Final Report Summary - CLEARWATERPMPC (Development of an efficient environmentally-friendly Algae Control System, based on ultrasound technology, designed for use in bigger ponds and lakes)
Executive Summary:
The ClearWaterPMPC FP7 research for the benefits of SME project lasted three years from January 2012 to December 2013 and was divided into several work packages (WP) covering scientific research, system development and management, demonstration, innovation related activities and consortium management. The consortium consisted of partners from Netherlands, Norway, Greece, Lithuania, France and Poland. The ClearwaterPMPC team identified the main challenges of the Algae Control System and several opportunities to improve it.
The ClearwaterPMPC project sought to provide an environmentally-friendly technology for the treatment of algae that is based on ultrasound and modified existing operation and installation system, developed a new, independent of power supply from shore technology and provided improving to traditional algae controlling methods.
The idea of the ClearwaterPMPC project was to develop an algae management system by providing the autonomous operating algae control (satellite) unit that can operate in a broad spectrum of frequencies and with cleaning solution that continuously keeps the transducer free from sludge. Through improved technology, ClearWaterPMPC product is capable to selectively control algae, not only in ponds but also in larger waters, such as lakes.
Project Context and Objectives:
ClearWaterPMPC focused the attention on algae treatment system that is effective both from a technical and economical point of view. Today’s traditional algae controlling methods (e.g. aeration, chemical or biological additives, ultrasound and others) are not sufficiently effective when it comes to larger waters. There are high labour costs associated with the need for frequent maintenance and dosage. Another concern is the environmental impact in particular cases,
especially when chemicals are used.
The effect of eutrophication in natural lakes, ponds or water reservoirs is high production of planktonic algae and excessive growth of weeds and macro algae, leading to oxygen deficiency when they die, which in turn may lead to fish deaths, reduced biological diversity and bottom death. These conditions trigger a HAB (harmful algal blooms). Each year, numerous lakes world-wide are forced to close for all recreational use due to the growth of blue-green algae, forcing governments world-wide to release substantial annual budgets for cleaning measures.
The project was initiated to use an environmental-friendly and cost-effective method. Autonomous self-powered supporting satellite units (buoys) can be located at selected points in the lake. These units are equipped with an ultrasound acoustic system which is remotely programmable and able to generate frequencies that will bring the gas vesicles of blue-green algae cells to resonance, thereby rupturing the cell. Controlling the algae growth with ultra sound is a well-established technology that has existed for many years. The treatment is efficient for ponds and has also been tried for treating algae in smaller lakes. The biggest problems with current products are the limited coverage ranges. In order to achieve efficient treatment of lakes and bigger ponds, The ClearWaterPMPC project, brings four major concerns that have to be solved when using ultra sound. The unresolved issues are:
• Monitoring of present algae species
• Remote configurable ultra sound frequency and power
• Power supply
• Maintenance
This new approach leads to an essential reduction of consumed power, compared to the current state-of-the-art ultra sound transmitters, which have no capability for monitoring and distinguishing between the present algae species, operating as they do on multiple frequencies to generally cover the most common species.
The project had several goals and objectives.
Scientific Objectives:
• Identification and investigation of the impact on the eco- system by using ultra sound. Identify power levels and a frequency span that are not harmful. Determination and investigation of ultra sound propagation, based on chosen frequencies and power levels
• Identification of cyanobacterial species and their morphological and toxicological characteristics
• Determination of the optimal ultrasonic frequencies and power levels, which perform best for destruction of the 5 most common algae species in Europe.
Technological Objectives:
• Development of an ultra sound acoustic system that can operate in a broad spectrum of frequencies (25 -100kHz)
• Development of an ultra sonic transducer cleaning solution that continuously keeps the transducer free from sludge
• Development of an autonomous operating algae control (satellite)unit
• Development of an algae management system
Project Results:
Please provide a description of the main S & T results/foregrounds.
The objective of the ClearWaterPMPC is to develop a system to destroy precisely the algae species that happen to be present at any given time. This is a very important feature, because the blooming of non-harmful algae is the basis of the inherent food webs of all lake ecosystems. current ultrasonic systems use a non-selective ultrasonic program, thereby reducing efficiency and risking targeting other (non-harmful) algae species as well. Zooplanktons grazing on the diatoms are eaten by fish larvae and crustaceans, again feeding the trout population, and so forth. When the diatoms are outcompeted by for instance blue-greens, the natural food web is changed dramatically. Only very few species of zooplankton are efficient grazers of Cyanobacteria; they are not removed until the bloom collapses from a lack of nutrients and light. The biomass then sinks to the bottom of the lake.
Traditional algae controlling methods (e.g. aeration, chemical or biological additives, ultrasound waves and other methods) are not sufficiently effective. There are high labor costs associated with the need for frequent maintenance and dosage. The methods are often too expensive for large areas. Another major concern with chemical or biological additives is their environmentally hostile impact on other species of aquatic ecosystems.
The unique function of the proposed ClearWaterPMPC product is that it will be capable to selectively control algae, not only in ponds but also in larger waters, such as lakes. The treatment is applied using an environmental-friendly and cost-effective method. Autonomous self-powered supporting satellite units (buoys) will be located at selected points in the lake. These units are equipped with an ultrasound acoustic system which is remotely programmable and able to generate frequencies that will bring the gas vesicles of blue-green algae cells to resonance, thereby rupturing them cell. Algae species, like green algae, do not have gas vesicles, but their contractual vacuoles connected with the function of the plasmalemma are damaged preventing the algae to obtain fluids, nutrients and to control their internal pressure. Without these functions, these single celled algae die.
The objectives that needed to be realized during the project where the following:
• Identification and investigation of the use of ultrasound on a water ecosystem. This objective can be divided into the following:
o Identify the impact on the ecosystem by using ultrasound
o Identify power levels and a frequency span that are not harmful
o Determine the ultrasound propagation based on chosen frequencies.
• Identification of common cyanobacterial species and their morphological characteristics.
• Determination of the optimal ultrasonic characteristics for optimal algae destruction.
• Development of an ultrasound acoustic system that can operate in a broad spectrum of frequencies (25-100 kHz)
• Development of an ultrasonic transducer cleaning solution that continuously keeps the transducer free from sludge.
• Development of an autonomous operating algae control (satellite) unit.
• Development of an algae management system.
During the project, the following objectives where reached and form a part of the foreground of this project. Mort particularly, during the project, the following was realized:
• A literature study was created to identify the impact of ultrasound on the environment, determine the most common cyanobacteria blooms and identify parameters that can be used to determine their species, when using online measurements. (D.1.1 report on the scientific work)
• Several ultrasound acoustic test-rigs where developed to use on laboratory scale, to determine the most optimal ultrasound characteristics for algae destruction (D1.2 ultrasound acoustic test rig).
• A final report was created that identifies the most optimal ultrasonic parameters based on the laboratory study (D.1.3 Report on algae destruction test carried out with ultrasound)
• A final electro acoustic system was designed to be equipped on the buoys systems in the lake in Poland. (D.2.1 Prototyped electro acoustic system including documentation)
• After completion of 2 buoy systems, a Master and a Slave, both have been installed in a lake in Poland to control algae. From this, a report has been produced in regard to effect of the algae, spatial coverage of the ultrasound and practicality of the system (D.2.2 Technical and biological test and verification report).
• A software was developed that could be used to control the buoy by changing ultrasonic parameters and viewing data coming from the water quality sensors (D.3.1 Control unit design specification including external sensors)
• A prototyped Control Unit Design documentation and risk assessment of the ClearWater system, technical and operational requirements for the buoy control and detailed design of HW and SW was created based on the integration of all components. (D.3.2 Prototyped control unit design documentation and risk assessment).
• A management system has been specified for the Clearwater system (D.4.1. Management system specification)
• A buoy solution was developed, that could support the electro-acoustic systems, water quality sensors and hardware and could provide them with power by mains of solar energy (D.4.2. Buoy Solution)
• The management system has been verified and an online software has been created to make changes to the ultrasonic equipment and review water quality data (D4.3 Management system and design documentation)
• A complete prototype of ClearWater satellite unit for practical operation, containing: ultrasound acoustic system, control unit, algae and environmental sensor system, and powering unit integrated into a floating buoy has been produced (D.5.1. Prototyped Clearwater system and system design documentation)
• A test and validation report was created based on the deployment of the 2 buoys in a lake in Poland (D5.2. Test and Validation report)
• A video of the installation and operation of the Clearwater buoys has been created (D.7.3. Video of project results)
• A preliminary (D.7.1 Plan for exploitation and dissemination-interim) and final (D.7.4. Plan for exploitation and dissemination-final) plan for dissemination has been created and executed (D7.2. Publication of non-sensitive results at dissemination)
• A project web site was created to communicate results with the general public (D8.2 Web page for project)
D.1.1 Report on the scientific work
During literature study IMGW-PIB made a research of occurrence of Cyanobacterial blooms in European lakes, most important species which causes blooms in Europe and characterized the main factors of stimulating or inhibit their growth. Cyanobacterial blooms are a common problem occurring in Europe and in other parts of the world. Their occurrences can be both the symptom and the indicator of water eutrophication. Cyanobacteria are highly opportunistic organisms. The effects of cyanobacterial blooms include high biomass concentration, biodiversity decline, and high oxygen deficits that influence the entire limnic ecosystem. Bloom occurrences on lakes are correlated, to a considerable degree, with weather conditions and consequently with climate conditions in a given area. In the case of Northern Europe, cyanobacterial blooms are observed mostly during the summer season. IMGW-PIB characterized the main meteorological and hydrological, physico-chemical, biological factors of stimulating or inhibit the cyanobacteria growth. IMGW-PIB also made a
characteristics of blue-green algae bloom and identified the main species which causes blooms in Europe. Bloom is defined as a profuse growth of one or more phytoplankton species. The consequences of cyanobacterial blooms are: - decreased oxygen concentration, - decreased biodiversity, - negative effects on water taste and odour, - decreased recreational value of lakes, - presence of cyanobacterial toxins in water. The cyanobacterial species which cause most problems are Microcystis aeruginosa, Planktothrix agardii, Aphanizomenon flos-aquae, and Anabaena flos-aquae.
D.1.2 Ultrasound Acoustic Test-rig
Based on the required technical parameters for this application, we analyzed various information sources to determine the necessary operational and constructional parameters for the transducers that would be used in the test rig. The requirement was that the transducer should efficiently operate in the frequency range from 20 to 80 kHz. In parallel, we assembled the necessary laboratory setup for evaluating and measuring electro-acoustic transducers for under water applications. We acquired the necessary missing equipment: calibrated hydrophones, various piezoelectric ceramic elements, electrical signal generators, and other necessary equipment for evaluating and measuring acoustic signals.
During this work task (evaluation) process, we practically determined that the transducers that are currently available in the market do not meet the requirements for this application and are not particularly well suited to reach the objectives of this work task, because all of the evaluated transducers had inadequate frequency response in the range of 20 to 80 kHz. Therefore, it was necessary to develop new transducers to meet the required parameters. Based on thorough analysis of information sources and our own experience in scientific work, analysis of the required types of vibrations for piezoelectric ceramic based transducers was carried out to maximally increase the efficiency of the transducer to be designed for continuous under water operation in the required frequency range. For applications in water environments, flexural, radial and longitudinal vibrations are suitable.
D.1.3 Report on algae destruction test carried out with ultrasound
The first trial was run in June, when the cultures of Anabaena were ready to be inoculated in the large tanks. The amplitude was set at 40 V. As the first two weeks of the experiment no decrease was detected in the different treatments compared with the control, it was decided to be changed to 80 V amplitude (20th of June). However, we decided to stop the trial as the general tendency was that algae declined in all treatment including the control (tank 6).
In the second trial with Anabaena, which was made in July, more clear results were obtained as the biomass in all treatments was lower than in the control tank. The conclusions from these trials were the following:
1. Anabaena proved to be quite tolerant species against ultrasound treatment
2. Amplitude of ultrasound is a decisive factor to work against resistant cyanobacteria
3. The lowest densities were obtained in the second trial with frequencies 55-65 and 70-80 kHz.
Some problems with up-scaling of Microcystis delayed out next trial which started in the end of August. This could probably be explained by the high temperature in the polyethylene bags. The initial inoculum, as may be noted, was much lower than in the case of Anabaena which was inoculated at higher cell densities. The same parameters as used in earlier trials were applied in the first experiment with Microcystis. The conclusion from this experiment was that Microcystis is far less resistant that Anabaena to ultrasound treatment and the cell densities fall down to zero in all treatments except control at the end of the experimental period.
D.2.1 Prototyped electro acoustic system including documentation
The design of the electroacoustic transducer for the buoy is based on our experience with the ultrasonic transducer that was designed for the test rig. The transducer for the buoy is designed for continuous under water operation in the frequency range of 20-100 kHz. To maximally increase the efficiency of the transducer, we chose a piezoelectric ceramic core based on a Langevin transducer, which enable to reach maximum amplitude of vibrations while having relatively small geometrical dimensions of the piezoelectric ceramic based core.
We chose two types of elastic materials – steel and aluminum. We chose the dimensions of these cylindrical parts so that a minimum of 5 resonances would be present in the frequency range of 20 – 100 kHz. Additional resonances were present in the frequency range of 100-200 kHz; therefore, it is possible to use the transducer in those higher if such a need would arise. Aluminum was chosen because it has similar acoustic impedance compared to the matching layers that will be in contact with water. In addition, amplitude is increased in the aluminum part of the core because it has lower acoustic impedance compared to piezoelectric ceramic elements. This way we can achieve a good transmittance of the vibrations of the transducer into water and the efficiency of the transducer is maximized.
We should note that by designing the core in such a way, we effectively shield the transducer from producing undesired electromagnetic radiation. The transducer does not radiate electromagnetic energy into the environment and therefore is considered a “clean” transducer.
D.2.2 Technical and biological test and verification report
The performance of the buoys was tested based on different factors. The coverage of the ultrasound throughout the lake, was measured with a hydrophone after deploying the buoys on several locations in the lake. The effect on the treatment of algae was tested by IMGW by taking regular water samples and comparing these too samples from previous years and from data collected at surrounding lake sites. The overall efficiency of the system was monitored as well, looking at the power consumption of the electro-acoustic system, the flexibility of the software and the efficiency of the solar power system.
After a few hours of operation it was discovered that the charge control unit, equipped on the Buoys was not suitable to deal with the power draw of the acoustic system. Because this system, suddenly draws a very high amount of power, the charge controller would shut down the complete buoy. Therefore, the ultrasound was set to a lower power output during the rest of the trial. After the installation of the buoys in the Skrzynki Male lake, acoustic pressure distribution in the lake was measured with only active buoy. Due to limited abilities of the power supply, the amplitude of the signal generator was set to 140 V. The acoustic pressure drops with distance as expected, and 200 meters away from the buoy there’s still significant acoustic pressure present. In regard to the effect of the ultrasound on algae, the results obtained do not show a clear trend of decrease in the size of any of the taxonomic groups of phytoplankton, or clear, unambiguous differences between the positions. During the trial, one of the buoys has been flipped over, making it impossible to finalize the test with 2 ultrasonic systems. This made it more difficult to interpret the results taken from the samples.
D.3.1 Control unit design specification including external sensors
The Buoy Controller Software (SW) consists of a number of modules. Some are written especially for this project and some are standard driver modules supplied by the vendors. All buoy SW is written in standard ANSI C. All modules have a dedicated include file (i.e. GPS.H) with the external references necessary to interface with the module (traditional C style). The project specific modules are:
GPS.C: The character stream from the GPS module is parsed and decoded. The values for longitude and altitude are stored in the buoy’s memory and reported to the Master on request. The GPS module also provides a correct time that is used to maintain the real time clock (time and date) in each buoy.
SENSORS.C This module will adress the correct sensor and retrieve information from each of the connected sensors. The sensors communicate physically through a RS485 interface and are addressed by use of the Modbus protocol. The Modbus functionality is taken care of in this module. Sensor data is stored in an array of data inside the buoy and is reported to the Master buoy on request.
UART.C The UART module takes care of the serial communication between literally all peripherals. A standard interface is used for all serial channels, providing RX and TX buffers, interrupt handling etc in a standardized manner. The buffer sizes are tailored to each peripheral to maintain the RAM memory budget.
RS485.C The RS485 module takes care of the RS485 based communication (with the sensors). EEPROM24AA64.C The EEPROM communicates through an I2C bus. The processor supports the low-level functionality and this module takes care of the high-level communication necessary to store and retrieve data in a standard, serial EEPROM. The EEPROM is used for storing vital configuration information (like buoy serial number, identification, radio channel for communication with Master etc) that needs to survive power down and loss of backup battery power.
GPRS.C This module is only active in the Master buoy. The GPRS module takes care of data communication with the Control Server. The module includes a state machine that configures the GPRS modem, connects with a server and transfers data and configuration information to and from the Control Server using the HTTP protocol.
ADC.C The ADC module handles the Analog to Digital Controller inside the controller. The ADC is used in this project to monitor battery and charger status. If battery voltage falls below a certain value it may be necessary to turn down the US amplitude to save power. Low battery voltage will also be reported as an alarm to the Master.
RTC.C The RTC module keeps track of time and date. It is synchronized with the real time information retrieved by the GPS receiver. The time and date is reported together with the sensor status.
MAIN.C The MAIN module initiates all modules and administrates the RTX OS. This module also handles the Watchdog - If the system for some reason should shut down or freeze for a certain period the controller will be reset and start over.
USDRIVER.C The USDRIVER module handles the Ultra Sonic Driver system. It will configure frequencies and amplitudes used by the US drivers. The US Drivers communicates through RS232 and Modbus.
ISM.C The ISM module handles configuration of the radio modem communication. Most prewritten driver modules are written by the supplier of the controller,
ST Micro. Some are written by the supplier of the development system, Keil. In a number of modules it has been necessary to make some changes to adapt the drivers to this application. A simple Real Time Operative System (OS) is used:
RTX. The OS is mainly used for task switching. The OS is supplied by Keil. It has a limited functionality but requires very little resources in form of memory and CPUtime. It is thus well suited for embedded applications like this. The RTX is configured to run the following tasks: GPRS task is called every 0.5 second - Start state machine to go through the steps to configure, connect and transfer data to and from server - This task is active in the Master buoy only GPS task is called every 2 sec -Interpretation of data from GPS according to NMEA protocol. Updates current position and time.
SENSORS task is called every 10 to 1000 minutes. The frequency is configurable by operator through Control Server - The Master buoy will request all Slaves to prepare sensor information. Sensor information is sent to the Control Server. New instructions from the Control Server are sent to Slaves, which will configure the US drivers accordingly.
CLOCK task is called every second – Monitor battery voltage and other critical system status - Reset Watchdog The first version of the software is tested on a commercial development system from Keil: Uxxxxx200.
Detailed Design Buoy Controller HW The controller is designed with a STM32F407 CPU which is a single chip device with a different choice of serial interfaces suited for this application. Programing and testing is done through a standard USB interface, thus this device is easy to use for implementing new functions or new updates. The Controller is designed with a total of eight ports, each with a serial interface that can be configured for different interface standards. Each port has a power connection that can be set to +5V, +12V or +24V from the inside using straps. This allows different types of sensors to be connected to the controller without the need to change the hardware configuration.
D.3.2. Prototyped control unit design documentation and risk assessment
A ClearWater system consists of a centralized management with system of buoys. Buoys contain a number of sensors to keep track of temperature (water and air), chlorophyll, dissolved oxygen. The information from each buoy is sent by GPRS through the internet to a management database and presented to a user through a web browser. The management system returns a signal to each buoy to start transmission of ultrasound based upon the information received from the sensors and the threshold levels set by the operator.
Risk has been evaluated in every weekly meeting in the project. Most of the risk has been related to delays, or events that have influence on the progress of the project. The technical complexity of this project has been of a medium level, while management risk has been of greater concern as available human resources at the right time. Significant results: The risk has been assessed and there were not discovered any high technical risk.
D.4.1 Management system specification
The management and control system consists of a constantly running server application taking care of the continuous data monitoring, and a web-application servicing both the buoy communication and the management interface. The system was implemented using object oriented design, with traditional application, business and data layer. The web service, the management application and the control application are all using the same data layer, and many common functions from the business layer. It is possible to run the web service and the management application in separate web server applications (and consequently on different computers) , as well as running them in the same application. The Microsoft IIS server provides the necessary parallelism needed for simultaneous operations from several buoys or management users. The system was implemented in Microsoft Visual Studio, for running under Microsoft IIS and .NET framework present. Extensive use of included mechanisms for “local” update was provided updated data on the pages without need for whole page refresh. (AJAX or similar .NET methods) Preferred programming language for the management system is C#. Data model for the database was specified with an entity relation diagram as well as initial implementation on SQL Server Express for reference. The database was implemented in a Microsoft SQL server in the final system. The necessary tools for database development are integrated in the Visual Studio development IDE. The data layer will provide for storage, retrieval or modification of records in the database. Classes will be constructed for the necessary objects. The business layer will provide for the necessary handling of the incoming status records from buoys by analyzing the data against alarms /triggers specified for the buoy. The response sent contains any necessary changes in operation based on what the business layer decides. As for the management solution the business layer will decide how to implement changes requested from user, or present reports based on configurations in the system. For the web service communication part and the web pages in the management application the application layer consists of the “pages” in the web application. These pages will instantiate classes from business,- and data layer to serve their clients. For the Control app, the application layer will consist of a continuously running program, controlled by timers and events from the database. It will also provide for inter-process communication with other parts of the system to handle urgent events. Configuration of the system will be provided by using application config files provided by .NET application model.
D.4.2 Buoy Solution
The buoy was designed as a light platform to be deployed in shallow lakes and ponds for easy deployment, but still rugged enough to withstand the operational requirements. The system has been equipped with solar panels and batteries with sufficient power for continuously operation during the summer season. The power is distributed to the control unit and the ultrasound driver which consumes most of the energy when transmitting high power ultrasound signal.
Three modular floating was designed with a platform in the middle for the controller and batteries, while the sensors were attached to submergible arms to be lowered in to the water when the buoy was moored. This allowed the buoy to be moved without risking the sensors to be destroyed during the transportation. The controller and sensors where integrated with the buoy and tested in controllable conditions in the lab before the buoy were ready to be deployed. All mechanical parts were available and installed, but there were still some construction to be done with both the software and ultrasound driver.
D.4.3 Management system and design documentation
During the development of the management system, it was decided not to divide the management system into 2 systems (master and slave), as all the business logic was managed by the web application. During the operation of the buoys, the triggers and responses of the web application where specified. A functioning web site has been in place since deploying the buoys.
D.5.1 Prototyped Clearwater system and system design documentation
A complete prototype of ClearWater satellite unit for practical operation, containing: ultrasound acoustic system, control unit, algae and environmental sensor system, and powering unit integrated into a floating buoy has been produced. The powering unit is be based on solar panel module. The controller, sensors and ultrasound generator and transducers have been integrated with the buoy and the solar panels and batteries. This includes
• all cables between the units, antennas and external GPS.
• Submergible sensors measure chlorophyll (algae in the water), water temperature, pH, carbon dioxide in water and dissolved oxygen.
• The ultrasound generator and transducer are separated units that receive commands from the controller.
The final integration took place in Kornik Poland where two buoys were put into operation in a small lake. There were some problems due to wrong power selected to one of the probe ports sending +24V instead of +12V, while other problem were related to mechanical failure of the probes and activators.Both prototype of the controller and the generator worked after a few modifications to the HW and SW. The controller uses GPRS network for the re mote communication and ISM radio for the short range communication. Only the GPRS radio was used for communication during the test.
The controller was designed with a configurable interface that allows different type of equipment to be attached. This is a flexible design for future need, but also requirees the operator to be sure that the correct voltage is selected for the type of instrument selected to the port. One of the controllers operated all summer from mid June to October, while one of the boyos had to be replaced due to sabotage and the testing site. The controller is able to receive SW updates through the GPRS modem. This allows updates to be sent without the need to visit the unit on site.
D.5.2 Test and validation report
The buoy system was monitoring the environment data continuously the whole summer sending live data to the web management server and the operator could track and send commands from a standard web server. Based on this, a test and validation report was created.
Analysis of water samples taken from the lake during the tests showed that there are no concentrations of nitrogen and phosphorus, which would en sure the rapid development of cyanobacteria. However it should be noted, with full conviction that the ultrasound emitter contributed to a reduction in phytoplankton abundance in the Skrzynki Male Lake. Based on data analysis of number of relevant groups of organisms phytoplankton and comparing it to the information on the operation of the emitter, it should be noted that the ultrasound emission could help to reduce the number of green algae (Chlorophyta) and on some level yellow algae (Chrysophyceae) and to some extent of diatoms (Bacillariophyta). For other groups of phytoplankton that have been identified in the Skrzynki Male lake the greatest importance for their development was primarily the concentration of easily assimilable nitrogen and phosphorus compounds and water temperature. In addition to the analyzed data which support at least partial emitter efficiency, the information derived from local inhabitants is also important. They are in agreement that during the period of the buoy measuring, the lake was clearly cleaner (greater transparency) and there were no algal scum like the one that occurred on the surface of the lake in previous years. At the same time, however, they expressed a clear concern about the behavior of the fish, which, at least in the first phase of the startup of the ultrasound, cut down on feeding. The results obtained for the Skrzynki Male Lake do not prove that the emission of ultrasound cannot be effective in any case. The effect of the emitter may depend on the specifics of the lake, among others. The Skrzynki Male Lake is dominated by thin filamentous species without aerotops (gas vesicles which allows algae to regulate their position in the water column). Perhaps the influence of the emitter on species with aerotops (eg, Planktothrix sp., Microcystis sp., before Anabaena sp. now Dolichospermum sp.) would be different. In addition, the same test method hinders unambiguous interpretation of the data. It cannot be excluded that the phytoplankton assemblage that has been found in July 26th had been at least partly shaped by the earlier inclusion of the emitter and reduced the development of blue-green algae. In this case, ultrasound would be able to prevent cyanobacteria blooms, but not fight them. Against such thesis,however, a significant increase in the number of blue-green algae is proven, despite the emission of ultrasound in the second half of August and September.
D.7.3. Video of project results
A video was created during installation of the buoys, that explains the assembly, mooring, setup and use of the buoys. It shows the location and the use of the software.
D.7.1 Plan for exploitation and dissemination-interim, D.7.4. Plan for exploitation and dissemination-final and D7.2. Publication of non-sensitive results at dissemination
The Clearwater-PMPC project has been promoted at 23 different occasions. The target applications have been determined to be drinking water reservoirs, lakes and large irrigation reservoirs. The target user would be mainly be municipalities, but also owners of golf or other recreational estates. The main dissemination activities where speaking on seminars or in workshops. However, also tradeshows have been attended worldwide. Some of the target countries in which the project has been promoted is Australia, USA, South-Korea and Japan, because these countries have a high occurrence of blue-green algae bloom. Also within Europe there have been many events on which the Clearwater-PMPC project has been promoted
D.8.2 Web page for project
The project website www. clearwater-pmpc.com was established to provide communication and information of non-sensitive information to the wider public about the ClearWater project, as described under Work Package 8 – IPR, Training and Dissemination described in annex 1, Description of work.
Potential Impact:
The Clearwater-PMPC project has developed a buoy system that can control algae blooms in lakes autonomously, by monitoring and interpreting water quality parameters. These buoys work with an ultrasonic sound signal of specific frequency, amplitude, duration and form. The ultrasound signal is optimized based on the algae type present in the water and because of this, does not harm plants, insects or other life present in a lake. For this reason, the buoys developed under the Clearwater-PMPC project are particularly useful for algae control in natural lakes, dams and drinking water reservoirs. The range of such a buoy is approximately 500 meter diameter.
Eutrophication of inland and coastal waters is a world-wide environmental problem and serious efforts are needed to reduce emissions and improve the situation. Eutrophication is a problem for 53% of lakes, ponds, reservoirs and dams in Europe. The numbers for Asia (48%) and North America (54%) are more or less the same. Some of these waters are used to supply drinking water, while many have a recreational, cultural or bird sanctuary function. The consequences of eutrophication hinder many, if not all, of these functions.
Each year, numerous lakes world-wide are forced to close for all recreational use due to the growth of blue-green algae, forcing governments world-wide to release substantial annual budgets for cleaning measures. In the US, the harmful freshwater algal blooms (FHAB) are conservatively estimated to cost the US.economy between 2.2 and 4.6 billion dollars annually. In addition to being expensive, present measures for abatement of blue-green algae are environmentally risky and can lead to problematic results. EU and US have together proposed a collaborative program to identify areas where collaboration will lead to significant progress in solving the HABs (harmful algal blooms).
For the Clearwater-PMPC buoy, we have defined the most important markets to be (1) recuperation areas in Europe that suffer from algae growth and (2) natural water sources used for water supply. Since algae blooming accelerates when water temperatures exceed approx. 20⁰C, the primary markets of Europe are the central and southern regions. The Scandinavian market possesses over 50% of all the lake surfaces of Europe and periodically encounter severe problems. Moreover, countries in Scandinavia more frequently use surface water from lakes, ponds and reservoirs as a source for their drinking water, thereby representing an attractive secondary market.
The reason for targeting these two markets is because they both face significant challenges regarding the growth of blue-green algae, although in different ways. The most important customers of the system will be local, regional and national authorities, as well as private owners of waterworks.
In estimating demand for the ClearWaterPMPC, we assume that 50% of the algae affected lakes and ponds in Europe are in need of treatment due. Further, we have evaluated the number of lakes according to size, desirable treatment and the number of potential units demanded. We estimate that 1 ClearWaterPMPC satellite unit is required to treat 20 ha (200,000 square metres) of water surface. Through previous studies, it was found that in Europe a total of 897,620 Ha of lake are affected by eutrophication. Leading to a total of 448,810 Ha of lake that require treatment with the ClearwaterPMPC buoy.
Using the above figures, this is a potential market for 22,440.5 ClearwaterPMPC units in total. Estimated at a value of EUR 15.000 per buoy, the potential market value would be EUR 336 million.
The main dissemination activities
The ClearWaterPMPC project has planned significant dissemination activities from the very start of the project in order to raise public participation and awareness at both private customers as national authorities. The partners of the project (IMWM, HCMR, KTU, TI, IK, ST and LG-S) have contributed in the dissemination process with deliverables as allocated in WP7 of the project.
A plan for using and disseminating knowledge obtained during the project was developed during the first stage of the project. The plan was aimed at raising awareness in the target markets. The adopted dissemination strategy focused on providing information to municipalities, universities and lake owners from the industry, with as a main goal to get more (trial) sites for the Clearwater PMPC buoys.
The ClearWaterPMPC project website (www.clearwater-pmpc.com) has been fully operational during the whole duration of the Project, and was continuously updated for the public audience. On the website all project highlights and relevant results has been presented as well as the updates that appeared every 3 months as the project progressed. The project webpage consists of an open part (presenting results and news to the broader public, and an internal part to be accessed via username and password by the project partners)
To further disseminate the project and the gained information during the project, several other promotional tools where developed by the consortium partners. Among these are:
PROJECT VIDEO, A promotion video has been produced and published, showing the installation and assembly of the buoys. This video is presenting the steps of installation and performance. This video has been shared at different online platforms for promotion purposes.
PROJECT LOGO, The project consortium has selected a logo that creates a well-distinguishable brand of the project. It includes the name of the project, and the initials of the scope of the project. The project logo is included on all materials and other documents concerning the project.
BROCHURE, A brochure presenting the benefits, technical specifications and the application (in lakes, dams, large ponds, etc.) of the integrated ClearWaterPMPC technology, has been designed and utilized as a marketing material in the second/final stage of the project.
PUBLICATIONS, Publications understood as all the different communications and publishing efforts made by the members of the consortium in order to promote, disseminate and increase visibility of the project, it has been a key element the Dissemination strategy adopted for ClearWaterPMPC.
These promotional tools have been spread at different platforms to spread awareness under the public. The project brochure was spread at several exhibitions to the public. Publications have been placed in several water related magazines, such as:
• Arab Water World (AWW) Magazine (Feb2013 Vol XXXVI Issue 2, pg. 21)
o Several responses have been received on this article from the middle east. Main replies came from the industry, looking to resell or commercialize the equipment locally.
• World Water (Vol 36, Issue 6, pg. 31-32) - Water Environment Federation.
o A few inquiries where received at our website, from the industry asking for more information about the system.
• Environmental-Expert.com
o This lead to many page views that could be tracked online.
o Inquiries came from the water industries to treat specific lakes within Europe.
o Some page-view notifications have also been received from municipalities and universities.
• World Water (Vol 36, Issue 6)
o A few inquiries where received at our website, from the industry asking for more information about the system.
• STREAM
• ClearWaterPMPC webpage, LG Sound B.V web-page.
A total of 20 events have been visited to disseminate the ClearwaterPMPC project. On these events promotional tools where spread, oral presentations where given, a workshop as organized or interviews where given to the local press.
• In total 8 exhibitions where visited in different countries in the world. Visited countries where Singapore, South Korea, Brazil, Spain, Japan, United Arab Emirates, UK and The Netherlands. Response from the different exhibitions came both from the general public, industry providers and municipalities.
o The main response from the municipalities was that this could be a very interesting product to solve algae blooms in drinking water reservoirs. In these applications the growth of algae causes problems with clogging of sand filters (in the water treatment plant) or with a bad taste and odour of the water, due to geosmins produced by cyanobacteria. A concern of many of the visitors from municipalities was how to protect the equipment from vandalism and birds.
o The main response on the project coming from the industry was very positive. Many people saw this as a good solution for drinking water reservoirs, lakes, recreational lakes but also industrial water and manmade lakes. Especially in the middle east, a lot of interest was generated in the sector of manmade lakes, as these lakes often have no ecological balance in place and no form of water treatment. Therefore, these lakes often suffer from severe algae blooms.
• Oral presentations where given at 2 conferences in the UK and in the United Arab Emirates. The average public at these seminars where between 25 and 70 persons. People attending the seminars where students, scientists and industry representatives and municipalities.
o The main response to the seminars came from scientist. Points of discussion with scientists where the ecological balance of a lake, and whether the ClearwaterPMPC system would disturb that. Other discussion points where the effect of ultrasound on zooplankton, such as Daphnia. These organisms are often referred to as a bio indicator for water quality, therefore it is important that they are kept alive. The release of toxins from cyanobacteria, once treated with ultrasound was also a point of discussion with scientists.
o Municipalities have approached us after the seminar with specific cases that might be interesting to the system.
• Workshops where organized by a company called Isle utilities. They have a Technology Approval Group, that is initiated by water and wastewater companies. Novel technologies are selected to present a workshop to these water companies. Main discussions at these workshops have been:
o The interest to set up trial locations for a Clearwater buoy at specific sites.
o Municipalities fear for a detrimental effect on the water quality and the balance within the ecosystem once algae are removed. This can result in lower oxygen levels, death of zooplankton etc.
o There is a doubt that the technology might increase toxin release of the cyanobacteria, once the ultrasound kills them and the cell ruptures.
o The fact was raised that the Clearwater system needs to be protected against vandalism and birds.
o Maintenance and installation where discussed.
• A 5 minute pitch and a 2 minute pitch where given at the Water Innovation Stimulation Award, organized by the Water Alliance in Amsterdam. The attendees where coming from Water companies, municipalities, universities and the industry. The main response at this event was:
o Water companies and municipalities claimed there is an occasional problem with blue-green algae in recreational lakes, but they do not have a direct intend to trial the ClearwaterPMPC technology.
List of Websites:
Project website address:
http://clearwater-pmpc.com/
Relevant contact details:
Coordinator
LG SOUND Nederland
Ing. Lisa Brand
Ba.Sc. (Biologist)
l.brand@lgsonic.com
www.lgsonic.com
For more contact details and project logo, please find attached file.
The ClearWaterPMPC FP7 research for the benefits of SME project lasted three years from January 2012 to December 2013 and was divided into several work packages (WP) covering scientific research, system development and management, demonstration, innovation related activities and consortium management. The consortium consisted of partners from Netherlands, Norway, Greece, Lithuania, France and Poland. The ClearwaterPMPC team identified the main challenges of the Algae Control System and several opportunities to improve it.
The ClearwaterPMPC project sought to provide an environmentally-friendly technology for the treatment of algae that is based on ultrasound and modified existing operation and installation system, developed a new, independent of power supply from shore technology and provided improving to traditional algae controlling methods.
The idea of the ClearwaterPMPC project was to develop an algae management system by providing the autonomous operating algae control (satellite) unit that can operate in a broad spectrum of frequencies and with cleaning solution that continuously keeps the transducer free from sludge. Through improved technology, ClearWaterPMPC product is capable to selectively control algae, not only in ponds but also in larger waters, such as lakes.
Project Context and Objectives:
ClearWaterPMPC focused the attention on algae treatment system that is effective both from a technical and economical point of view. Today’s traditional algae controlling methods (e.g. aeration, chemical or biological additives, ultrasound and others) are not sufficiently effective when it comes to larger waters. There are high labour costs associated with the need for frequent maintenance and dosage. Another concern is the environmental impact in particular cases,
especially when chemicals are used.
The effect of eutrophication in natural lakes, ponds or water reservoirs is high production of planktonic algae and excessive growth of weeds and macro algae, leading to oxygen deficiency when they die, which in turn may lead to fish deaths, reduced biological diversity and bottom death. These conditions trigger a HAB (harmful algal blooms). Each year, numerous lakes world-wide are forced to close for all recreational use due to the growth of blue-green algae, forcing governments world-wide to release substantial annual budgets for cleaning measures.
The project was initiated to use an environmental-friendly and cost-effective method. Autonomous self-powered supporting satellite units (buoys) can be located at selected points in the lake. These units are equipped with an ultrasound acoustic system which is remotely programmable and able to generate frequencies that will bring the gas vesicles of blue-green algae cells to resonance, thereby rupturing the cell. Controlling the algae growth with ultra sound is a well-established technology that has existed for many years. The treatment is efficient for ponds and has also been tried for treating algae in smaller lakes. The biggest problems with current products are the limited coverage ranges. In order to achieve efficient treatment of lakes and bigger ponds, The ClearWaterPMPC project, brings four major concerns that have to be solved when using ultra sound. The unresolved issues are:
• Monitoring of present algae species
• Remote configurable ultra sound frequency and power
• Power supply
• Maintenance
This new approach leads to an essential reduction of consumed power, compared to the current state-of-the-art ultra sound transmitters, which have no capability for monitoring and distinguishing between the present algae species, operating as they do on multiple frequencies to generally cover the most common species.
The project had several goals and objectives.
Scientific Objectives:
• Identification and investigation of the impact on the eco- system by using ultra sound. Identify power levels and a frequency span that are not harmful. Determination and investigation of ultra sound propagation, based on chosen frequencies and power levels
• Identification of cyanobacterial species and their morphological and toxicological characteristics
• Determination of the optimal ultrasonic frequencies and power levels, which perform best for destruction of the 5 most common algae species in Europe.
Technological Objectives:
• Development of an ultra sound acoustic system that can operate in a broad spectrum of frequencies (25 -100kHz)
• Development of an ultra sonic transducer cleaning solution that continuously keeps the transducer free from sludge
• Development of an autonomous operating algae control (satellite)unit
• Development of an algae management system
Project Results:
Please provide a description of the main S & T results/foregrounds.
The objective of the ClearWaterPMPC is to develop a system to destroy precisely the algae species that happen to be present at any given time. This is a very important feature, because the blooming of non-harmful algae is the basis of the inherent food webs of all lake ecosystems. current ultrasonic systems use a non-selective ultrasonic program, thereby reducing efficiency and risking targeting other (non-harmful) algae species as well. Zooplanktons grazing on the diatoms are eaten by fish larvae and crustaceans, again feeding the trout population, and so forth. When the diatoms are outcompeted by for instance blue-greens, the natural food web is changed dramatically. Only very few species of zooplankton are efficient grazers of Cyanobacteria; they are not removed until the bloom collapses from a lack of nutrients and light. The biomass then sinks to the bottom of the lake.
Traditional algae controlling methods (e.g. aeration, chemical or biological additives, ultrasound waves and other methods) are not sufficiently effective. There are high labor costs associated with the need for frequent maintenance and dosage. The methods are often too expensive for large areas. Another major concern with chemical or biological additives is their environmentally hostile impact on other species of aquatic ecosystems.
The unique function of the proposed ClearWaterPMPC product is that it will be capable to selectively control algae, not only in ponds but also in larger waters, such as lakes. The treatment is applied using an environmental-friendly and cost-effective method. Autonomous self-powered supporting satellite units (buoys) will be located at selected points in the lake. These units are equipped with an ultrasound acoustic system which is remotely programmable and able to generate frequencies that will bring the gas vesicles of blue-green algae cells to resonance, thereby rupturing them cell. Algae species, like green algae, do not have gas vesicles, but their contractual vacuoles connected with the function of the plasmalemma are damaged preventing the algae to obtain fluids, nutrients and to control their internal pressure. Without these functions, these single celled algae die.
The objectives that needed to be realized during the project where the following:
• Identification and investigation of the use of ultrasound on a water ecosystem. This objective can be divided into the following:
o Identify the impact on the ecosystem by using ultrasound
o Identify power levels and a frequency span that are not harmful
o Determine the ultrasound propagation based on chosen frequencies.
• Identification of common cyanobacterial species and their morphological characteristics.
• Determination of the optimal ultrasonic characteristics for optimal algae destruction.
• Development of an ultrasound acoustic system that can operate in a broad spectrum of frequencies (25-100 kHz)
• Development of an ultrasonic transducer cleaning solution that continuously keeps the transducer free from sludge.
• Development of an autonomous operating algae control (satellite) unit.
• Development of an algae management system.
During the project, the following objectives where reached and form a part of the foreground of this project. Mort particularly, during the project, the following was realized:
• A literature study was created to identify the impact of ultrasound on the environment, determine the most common cyanobacteria blooms and identify parameters that can be used to determine their species, when using online measurements. (D.1.1 report on the scientific work)
• Several ultrasound acoustic test-rigs where developed to use on laboratory scale, to determine the most optimal ultrasound characteristics for algae destruction (D1.2 ultrasound acoustic test rig).
• A final report was created that identifies the most optimal ultrasonic parameters based on the laboratory study (D.1.3 Report on algae destruction test carried out with ultrasound)
• A final electro acoustic system was designed to be equipped on the buoys systems in the lake in Poland. (D.2.1 Prototyped electro acoustic system including documentation)
• After completion of 2 buoy systems, a Master and a Slave, both have been installed in a lake in Poland to control algae. From this, a report has been produced in regard to effect of the algae, spatial coverage of the ultrasound and practicality of the system (D.2.2 Technical and biological test and verification report).
• A software was developed that could be used to control the buoy by changing ultrasonic parameters and viewing data coming from the water quality sensors (D.3.1 Control unit design specification including external sensors)
• A prototyped Control Unit Design documentation and risk assessment of the ClearWater system, technical and operational requirements for the buoy control and detailed design of HW and SW was created based on the integration of all components. (D.3.2 Prototyped control unit design documentation and risk assessment).
• A management system has been specified for the Clearwater system (D.4.1. Management system specification)
• A buoy solution was developed, that could support the electro-acoustic systems, water quality sensors and hardware and could provide them with power by mains of solar energy (D.4.2. Buoy Solution)
• The management system has been verified and an online software has been created to make changes to the ultrasonic equipment and review water quality data (D4.3 Management system and design documentation)
• A complete prototype of ClearWater satellite unit for practical operation, containing: ultrasound acoustic system, control unit, algae and environmental sensor system, and powering unit integrated into a floating buoy has been produced (D.5.1. Prototyped Clearwater system and system design documentation)
• A test and validation report was created based on the deployment of the 2 buoys in a lake in Poland (D5.2. Test and Validation report)
• A video of the installation and operation of the Clearwater buoys has been created (D.7.3. Video of project results)
• A preliminary (D.7.1 Plan for exploitation and dissemination-interim) and final (D.7.4. Plan for exploitation and dissemination-final) plan for dissemination has been created and executed (D7.2. Publication of non-sensitive results at dissemination)
• A project web site was created to communicate results with the general public (D8.2 Web page for project)
D.1.1 Report on the scientific work
During literature study IMGW-PIB made a research of occurrence of Cyanobacterial blooms in European lakes, most important species which causes blooms in Europe and characterized the main factors of stimulating or inhibit their growth. Cyanobacterial blooms are a common problem occurring in Europe and in other parts of the world. Their occurrences can be both the symptom and the indicator of water eutrophication. Cyanobacteria are highly opportunistic organisms. The effects of cyanobacterial blooms include high biomass concentration, biodiversity decline, and high oxygen deficits that influence the entire limnic ecosystem. Bloom occurrences on lakes are correlated, to a considerable degree, with weather conditions and consequently with climate conditions in a given area. In the case of Northern Europe, cyanobacterial blooms are observed mostly during the summer season. IMGW-PIB characterized the main meteorological and hydrological, physico-chemical, biological factors of stimulating or inhibit the cyanobacteria growth. IMGW-PIB also made a
characteristics of blue-green algae bloom and identified the main species which causes blooms in Europe. Bloom is defined as a profuse growth of one or more phytoplankton species. The consequences of cyanobacterial blooms are: - decreased oxygen concentration, - decreased biodiversity, - negative effects on water taste and odour, - decreased recreational value of lakes, - presence of cyanobacterial toxins in water. The cyanobacterial species which cause most problems are Microcystis aeruginosa, Planktothrix agardii, Aphanizomenon flos-aquae, and Anabaena flos-aquae.
D.1.2 Ultrasound Acoustic Test-rig
Based on the required technical parameters for this application, we analyzed various information sources to determine the necessary operational and constructional parameters for the transducers that would be used in the test rig. The requirement was that the transducer should efficiently operate in the frequency range from 20 to 80 kHz. In parallel, we assembled the necessary laboratory setup for evaluating and measuring electro-acoustic transducers for under water applications. We acquired the necessary missing equipment: calibrated hydrophones, various piezoelectric ceramic elements, electrical signal generators, and other necessary equipment for evaluating and measuring acoustic signals.
During this work task (evaluation) process, we practically determined that the transducers that are currently available in the market do not meet the requirements for this application and are not particularly well suited to reach the objectives of this work task, because all of the evaluated transducers had inadequate frequency response in the range of 20 to 80 kHz. Therefore, it was necessary to develop new transducers to meet the required parameters. Based on thorough analysis of information sources and our own experience in scientific work, analysis of the required types of vibrations for piezoelectric ceramic based transducers was carried out to maximally increase the efficiency of the transducer to be designed for continuous under water operation in the required frequency range. For applications in water environments, flexural, radial and longitudinal vibrations are suitable.
D.1.3 Report on algae destruction test carried out with ultrasound
The first trial was run in June, when the cultures of Anabaena were ready to be inoculated in the large tanks. The amplitude was set at 40 V. As the first two weeks of the experiment no decrease was detected in the different treatments compared with the control, it was decided to be changed to 80 V amplitude (20th of June). However, we decided to stop the trial as the general tendency was that algae declined in all treatment including the control (tank 6).
In the second trial with Anabaena, which was made in July, more clear results were obtained as the biomass in all treatments was lower than in the control tank. The conclusions from these trials were the following:
1. Anabaena proved to be quite tolerant species against ultrasound treatment
2. Amplitude of ultrasound is a decisive factor to work against resistant cyanobacteria
3. The lowest densities were obtained in the second trial with frequencies 55-65 and 70-80 kHz.
Some problems with up-scaling of Microcystis delayed out next trial which started in the end of August. This could probably be explained by the high temperature in the polyethylene bags. The initial inoculum, as may be noted, was much lower than in the case of Anabaena which was inoculated at higher cell densities. The same parameters as used in earlier trials were applied in the first experiment with Microcystis. The conclusion from this experiment was that Microcystis is far less resistant that Anabaena to ultrasound treatment and the cell densities fall down to zero in all treatments except control at the end of the experimental period.
D.2.1 Prototyped electro acoustic system including documentation
The design of the electroacoustic transducer for the buoy is based on our experience with the ultrasonic transducer that was designed for the test rig. The transducer for the buoy is designed for continuous under water operation in the frequency range of 20-100 kHz. To maximally increase the efficiency of the transducer, we chose a piezoelectric ceramic core based on a Langevin transducer, which enable to reach maximum amplitude of vibrations while having relatively small geometrical dimensions of the piezoelectric ceramic based core.
We chose two types of elastic materials – steel and aluminum. We chose the dimensions of these cylindrical parts so that a minimum of 5 resonances would be present in the frequency range of 20 – 100 kHz. Additional resonances were present in the frequency range of 100-200 kHz; therefore, it is possible to use the transducer in those higher if such a need would arise. Aluminum was chosen because it has similar acoustic impedance compared to the matching layers that will be in contact with water. In addition, amplitude is increased in the aluminum part of the core because it has lower acoustic impedance compared to piezoelectric ceramic elements. This way we can achieve a good transmittance of the vibrations of the transducer into water and the efficiency of the transducer is maximized.
We should note that by designing the core in such a way, we effectively shield the transducer from producing undesired electromagnetic radiation. The transducer does not radiate electromagnetic energy into the environment and therefore is considered a “clean” transducer.
D.2.2 Technical and biological test and verification report
The performance of the buoys was tested based on different factors. The coverage of the ultrasound throughout the lake, was measured with a hydrophone after deploying the buoys on several locations in the lake. The effect on the treatment of algae was tested by IMGW by taking regular water samples and comparing these too samples from previous years and from data collected at surrounding lake sites. The overall efficiency of the system was monitored as well, looking at the power consumption of the electro-acoustic system, the flexibility of the software and the efficiency of the solar power system.
After a few hours of operation it was discovered that the charge control unit, equipped on the Buoys was not suitable to deal with the power draw of the acoustic system. Because this system, suddenly draws a very high amount of power, the charge controller would shut down the complete buoy. Therefore, the ultrasound was set to a lower power output during the rest of the trial. After the installation of the buoys in the Skrzynki Male lake, acoustic pressure distribution in the lake was measured with only active buoy. Due to limited abilities of the power supply, the amplitude of the signal generator was set to 140 V. The acoustic pressure drops with distance as expected, and 200 meters away from the buoy there’s still significant acoustic pressure present. In regard to the effect of the ultrasound on algae, the results obtained do not show a clear trend of decrease in the size of any of the taxonomic groups of phytoplankton, or clear, unambiguous differences between the positions. During the trial, one of the buoys has been flipped over, making it impossible to finalize the test with 2 ultrasonic systems. This made it more difficult to interpret the results taken from the samples.
D.3.1 Control unit design specification including external sensors
The Buoy Controller Software (SW) consists of a number of modules. Some are written especially for this project and some are standard driver modules supplied by the vendors. All buoy SW is written in standard ANSI C. All modules have a dedicated include file (i.e. GPS.H) with the external references necessary to interface with the module (traditional C style). The project specific modules are:
GPS.C: The character stream from the GPS module is parsed and decoded. The values for longitude and altitude are stored in the buoy’s memory and reported to the Master on request. The GPS module also provides a correct time that is used to maintain the real time clock (time and date) in each buoy.
SENSORS.C This module will adress the correct sensor and retrieve information from each of the connected sensors. The sensors communicate physically through a RS485 interface and are addressed by use of the Modbus protocol. The Modbus functionality is taken care of in this module. Sensor data is stored in an array of data inside the buoy and is reported to the Master buoy on request.
UART.C The UART module takes care of the serial communication between literally all peripherals. A standard interface is used for all serial channels, providing RX and TX buffers, interrupt handling etc in a standardized manner. The buffer sizes are tailored to each peripheral to maintain the RAM memory budget.
RS485.C The RS485 module takes care of the RS485 based communication (with the sensors). EEPROM24AA64.C The EEPROM communicates through an I2C bus. The processor supports the low-level functionality and this module takes care of the high-level communication necessary to store and retrieve data in a standard, serial EEPROM. The EEPROM is used for storing vital configuration information (like buoy serial number, identification, radio channel for communication with Master etc) that needs to survive power down and loss of backup battery power.
GPRS.C This module is only active in the Master buoy. The GPRS module takes care of data communication with the Control Server. The module includes a state machine that configures the GPRS modem, connects with a server and transfers data and configuration information to and from the Control Server using the HTTP protocol.
ADC.C The ADC module handles the Analog to Digital Controller inside the controller. The ADC is used in this project to monitor battery and charger status. If battery voltage falls below a certain value it may be necessary to turn down the US amplitude to save power. Low battery voltage will also be reported as an alarm to the Master.
RTC.C The RTC module keeps track of time and date. It is synchronized with the real time information retrieved by the GPS receiver. The time and date is reported together with the sensor status.
MAIN.C The MAIN module initiates all modules and administrates the RTX OS. This module also handles the Watchdog - If the system for some reason should shut down or freeze for a certain period the controller will be reset and start over.
USDRIVER.C The USDRIVER module handles the Ultra Sonic Driver system. It will configure frequencies and amplitudes used by the US drivers. The US Drivers communicates through RS232 and Modbus.
ISM.C The ISM module handles configuration of the radio modem communication. Most prewritten driver modules are written by the supplier of the controller,
ST Micro. Some are written by the supplier of the development system, Keil. In a number of modules it has been necessary to make some changes to adapt the drivers to this application. A simple Real Time Operative System (OS) is used:
RTX. The OS is mainly used for task switching. The OS is supplied by Keil. It has a limited functionality but requires very little resources in form of memory and CPUtime. It is thus well suited for embedded applications like this. The RTX is configured to run the following tasks: GPRS task is called every 0.5 second - Start state machine to go through the steps to configure, connect and transfer data to and from server - This task is active in the Master buoy only GPS task is called every 2 sec -Interpretation of data from GPS according to NMEA protocol. Updates current position and time.
SENSORS task is called every 10 to 1000 minutes. The frequency is configurable by operator through Control Server - The Master buoy will request all Slaves to prepare sensor information. Sensor information is sent to the Control Server. New instructions from the Control Server are sent to Slaves, which will configure the US drivers accordingly.
CLOCK task is called every second – Monitor battery voltage and other critical system status - Reset Watchdog The first version of the software is tested on a commercial development system from Keil: Uxxxxx200.
Detailed Design Buoy Controller HW The controller is designed with a STM32F407 CPU which is a single chip device with a different choice of serial interfaces suited for this application. Programing and testing is done through a standard USB interface, thus this device is easy to use for implementing new functions or new updates. The Controller is designed with a total of eight ports, each with a serial interface that can be configured for different interface standards. Each port has a power connection that can be set to +5V, +12V or +24V from the inside using straps. This allows different types of sensors to be connected to the controller without the need to change the hardware configuration.
D.3.2. Prototyped control unit design documentation and risk assessment
A ClearWater system consists of a centralized management with system of buoys. Buoys contain a number of sensors to keep track of temperature (water and air), chlorophyll, dissolved oxygen. The information from each buoy is sent by GPRS through the internet to a management database and presented to a user through a web browser. The management system returns a signal to each buoy to start transmission of ultrasound based upon the information received from the sensors and the threshold levels set by the operator.
Risk has been evaluated in every weekly meeting in the project. Most of the risk has been related to delays, or events that have influence on the progress of the project. The technical complexity of this project has been of a medium level, while management risk has been of greater concern as available human resources at the right time. Significant results: The risk has been assessed and there were not discovered any high technical risk.
D.4.1 Management system specification
The management and control system consists of a constantly running server application taking care of the continuous data monitoring, and a web-application servicing both the buoy communication and the management interface. The system was implemented using object oriented design, with traditional application, business and data layer. The web service, the management application and the control application are all using the same data layer, and many common functions from the business layer. It is possible to run the web service and the management application in separate web server applications (and consequently on different computers) , as well as running them in the same application. The Microsoft IIS server provides the necessary parallelism needed for simultaneous operations from several buoys or management users. The system was implemented in Microsoft Visual Studio, for running under Microsoft IIS and .NET framework present. Extensive use of included mechanisms for “local” update was provided updated data on the pages without need for whole page refresh. (AJAX or similar .NET methods) Preferred programming language for the management system is C#. Data model for the database was specified with an entity relation diagram as well as initial implementation on SQL Server Express for reference. The database was implemented in a Microsoft SQL server in the final system. The necessary tools for database development are integrated in the Visual Studio development IDE. The data layer will provide for storage, retrieval or modification of records in the database. Classes will be constructed for the necessary objects. The business layer will provide for the necessary handling of the incoming status records from buoys by analyzing the data against alarms /triggers specified for the buoy. The response sent contains any necessary changes in operation based on what the business layer decides. As for the management solution the business layer will decide how to implement changes requested from user, or present reports based on configurations in the system. For the web service communication part and the web pages in the management application the application layer consists of the “pages” in the web application. These pages will instantiate classes from business,- and data layer to serve their clients. For the Control app, the application layer will consist of a continuously running program, controlled by timers and events from the database. It will also provide for inter-process communication with other parts of the system to handle urgent events. Configuration of the system will be provided by using application config files provided by .NET application model.
D.4.2 Buoy Solution
The buoy was designed as a light platform to be deployed in shallow lakes and ponds for easy deployment, but still rugged enough to withstand the operational requirements. The system has been equipped with solar panels and batteries with sufficient power for continuously operation during the summer season. The power is distributed to the control unit and the ultrasound driver which consumes most of the energy when transmitting high power ultrasound signal.
Three modular floating was designed with a platform in the middle for the controller and batteries, while the sensors were attached to submergible arms to be lowered in to the water when the buoy was moored. This allowed the buoy to be moved without risking the sensors to be destroyed during the transportation. The controller and sensors where integrated with the buoy and tested in controllable conditions in the lab before the buoy were ready to be deployed. All mechanical parts were available and installed, but there were still some construction to be done with both the software and ultrasound driver.
D.4.3 Management system and design documentation
During the development of the management system, it was decided not to divide the management system into 2 systems (master and slave), as all the business logic was managed by the web application. During the operation of the buoys, the triggers and responses of the web application where specified. A functioning web site has been in place since deploying the buoys.
D.5.1 Prototyped Clearwater system and system design documentation
A complete prototype of ClearWater satellite unit for practical operation, containing: ultrasound acoustic system, control unit, algae and environmental sensor system, and powering unit integrated into a floating buoy has been produced. The powering unit is be based on solar panel module. The controller, sensors and ultrasound generator and transducers have been integrated with the buoy and the solar panels and batteries. This includes
• all cables between the units, antennas and external GPS.
• Submergible sensors measure chlorophyll (algae in the water), water temperature, pH, carbon dioxide in water and dissolved oxygen.
• The ultrasound generator and transducer are separated units that receive commands from the controller.
The final integration took place in Kornik Poland where two buoys were put into operation in a small lake. There were some problems due to wrong power selected to one of the probe ports sending +24V instead of +12V, while other problem were related to mechanical failure of the probes and activators.Both prototype of the controller and the generator worked after a few modifications to the HW and SW. The controller uses GPRS network for the re mote communication and ISM radio for the short range communication. Only the GPRS radio was used for communication during the test.
The controller was designed with a configurable interface that allows different type of equipment to be attached. This is a flexible design for future need, but also requirees the operator to be sure that the correct voltage is selected for the type of instrument selected to the port. One of the controllers operated all summer from mid June to October, while one of the boyos had to be replaced due to sabotage and the testing site. The controller is able to receive SW updates through the GPRS modem. This allows updates to be sent without the need to visit the unit on site.
D.5.2 Test and validation report
The buoy system was monitoring the environment data continuously the whole summer sending live data to the web management server and the operator could track and send commands from a standard web server. Based on this, a test and validation report was created.
Analysis of water samples taken from the lake during the tests showed that there are no concentrations of nitrogen and phosphorus, which would en sure the rapid development of cyanobacteria. However it should be noted, with full conviction that the ultrasound emitter contributed to a reduction in phytoplankton abundance in the Skrzynki Male Lake. Based on data analysis of number of relevant groups of organisms phytoplankton and comparing it to the information on the operation of the emitter, it should be noted that the ultrasound emission could help to reduce the number of green algae (Chlorophyta) and on some level yellow algae (Chrysophyceae) and to some extent of diatoms (Bacillariophyta). For other groups of phytoplankton that have been identified in the Skrzynki Male lake the greatest importance for their development was primarily the concentration of easily assimilable nitrogen and phosphorus compounds and water temperature. In addition to the analyzed data which support at least partial emitter efficiency, the information derived from local inhabitants is also important. They are in agreement that during the period of the buoy measuring, the lake was clearly cleaner (greater transparency) and there were no algal scum like the one that occurred on the surface of the lake in previous years. At the same time, however, they expressed a clear concern about the behavior of the fish, which, at least in the first phase of the startup of the ultrasound, cut down on feeding. The results obtained for the Skrzynki Male Lake do not prove that the emission of ultrasound cannot be effective in any case. The effect of the emitter may depend on the specifics of the lake, among others. The Skrzynki Male Lake is dominated by thin filamentous species without aerotops (gas vesicles which allows algae to regulate their position in the water column). Perhaps the influence of the emitter on species with aerotops (eg, Planktothrix sp., Microcystis sp., before Anabaena sp. now Dolichospermum sp.) would be different. In addition, the same test method hinders unambiguous interpretation of the data. It cannot be excluded that the phytoplankton assemblage that has been found in July 26th had been at least partly shaped by the earlier inclusion of the emitter and reduced the development of blue-green algae. In this case, ultrasound would be able to prevent cyanobacteria blooms, but not fight them. Against such thesis,however, a significant increase in the number of blue-green algae is proven, despite the emission of ultrasound in the second half of August and September.
D.7.3. Video of project results
A video was created during installation of the buoys, that explains the assembly, mooring, setup and use of the buoys. It shows the location and the use of the software.
D.7.1 Plan for exploitation and dissemination-interim, D.7.4. Plan for exploitation and dissemination-final and D7.2. Publication of non-sensitive results at dissemination
The Clearwater-PMPC project has been promoted at 23 different occasions. The target applications have been determined to be drinking water reservoirs, lakes and large irrigation reservoirs. The target user would be mainly be municipalities, but also owners of golf or other recreational estates. The main dissemination activities where speaking on seminars or in workshops. However, also tradeshows have been attended worldwide. Some of the target countries in which the project has been promoted is Australia, USA, South-Korea and Japan, because these countries have a high occurrence of blue-green algae bloom. Also within Europe there have been many events on which the Clearwater-PMPC project has been promoted
D.8.2 Web page for project
The project website www. clearwater-pmpc.com was established to provide communication and information of non-sensitive information to the wider public about the ClearWater project, as described under Work Package 8 – IPR, Training and Dissemination described in annex 1, Description of work.
Potential Impact:
The Clearwater-PMPC project has developed a buoy system that can control algae blooms in lakes autonomously, by monitoring and interpreting water quality parameters. These buoys work with an ultrasonic sound signal of specific frequency, amplitude, duration and form. The ultrasound signal is optimized based on the algae type present in the water and because of this, does not harm plants, insects or other life present in a lake. For this reason, the buoys developed under the Clearwater-PMPC project are particularly useful for algae control in natural lakes, dams and drinking water reservoirs. The range of such a buoy is approximately 500 meter diameter.
Eutrophication of inland and coastal waters is a world-wide environmental problem and serious efforts are needed to reduce emissions and improve the situation. Eutrophication is a problem for 53% of lakes, ponds, reservoirs and dams in Europe. The numbers for Asia (48%) and North America (54%) are more or less the same. Some of these waters are used to supply drinking water, while many have a recreational, cultural or bird sanctuary function. The consequences of eutrophication hinder many, if not all, of these functions.
Each year, numerous lakes world-wide are forced to close for all recreational use due to the growth of blue-green algae, forcing governments world-wide to release substantial annual budgets for cleaning measures. In the US, the harmful freshwater algal blooms (FHAB) are conservatively estimated to cost the US.economy between 2.2 and 4.6 billion dollars annually. In addition to being expensive, present measures for abatement of blue-green algae are environmentally risky and can lead to problematic results. EU and US have together proposed a collaborative program to identify areas where collaboration will lead to significant progress in solving the HABs (harmful algal blooms).
For the Clearwater-PMPC buoy, we have defined the most important markets to be (1) recuperation areas in Europe that suffer from algae growth and (2) natural water sources used for water supply. Since algae blooming accelerates when water temperatures exceed approx. 20⁰C, the primary markets of Europe are the central and southern regions. The Scandinavian market possesses over 50% of all the lake surfaces of Europe and periodically encounter severe problems. Moreover, countries in Scandinavia more frequently use surface water from lakes, ponds and reservoirs as a source for their drinking water, thereby representing an attractive secondary market.
The reason for targeting these two markets is because they both face significant challenges regarding the growth of blue-green algae, although in different ways. The most important customers of the system will be local, regional and national authorities, as well as private owners of waterworks.
In estimating demand for the ClearWaterPMPC, we assume that 50% of the algae affected lakes and ponds in Europe are in need of treatment due. Further, we have evaluated the number of lakes according to size, desirable treatment and the number of potential units demanded. We estimate that 1 ClearWaterPMPC satellite unit is required to treat 20 ha (200,000 square metres) of water surface. Through previous studies, it was found that in Europe a total of 897,620 Ha of lake are affected by eutrophication. Leading to a total of 448,810 Ha of lake that require treatment with the ClearwaterPMPC buoy.
Using the above figures, this is a potential market for 22,440.5 ClearwaterPMPC units in total. Estimated at a value of EUR 15.000 per buoy, the potential market value would be EUR 336 million.
The main dissemination activities
The ClearWaterPMPC project has planned significant dissemination activities from the very start of the project in order to raise public participation and awareness at both private customers as national authorities. The partners of the project (IMWM, HCMR, KTU, TI, IK, ST and LG-S) have contributed in the dissemination process with deliverables as allocated in WP7 of the project.
A plan for using and disseminating knowledge obtained during the project was developed during the first stage of the project. The plan was aimed at raising awareness in the target markets. The adopted dissemination strategy focused on providing information to municipalities, universities and lake owners from the industry, with as a main goal to get more (trial) sites for the Clearwater PMPC buoys.
The ClearWaterPMPC project website (www.clearwater-pmpc.com) has been fully operational during the whole duration of the Project, and was continuously updated for the public audience. On the website all project highlights and relevant results has been presented as well as the updates that appeared every 3 months as the project progressed. The project webpage consists of an open part (presenting results and news to the broader public, and an internal part to be accessed via username and password by the project partners)
To further disseminate the project and the gained information during the project, several other promotional tools where developed by the consortium partners. Among these are:
PROJECT VIDEO, A promotion video has been produced and published, showing the installation and assembly of the buoys. This video is presenting the steps of installation and performance. This video has been shared at different online platforms for promotion purposes.
PROJECT LOGO, The project consortium has selected a logo that creates a well-distinguishable brand of the project. It includes the name of the project, and the initials of the scope of the project. The project logo is included on all materials and other documents concerning the project.
BROCHURE, A brochure presenting the benefits, technical specifications and the application (in lakes, dams, large ponds, etc.) of the integrated ClearWaterPMPC technology, has been designed and utilized as a marketing material in the second/final stage of the project.
PUBLICATIONS, Publications understood as all the different communications and publishing efforts made by the members of the consortium in order to promote, disseminate and increase visibility of the project, it has been a key element the Dissemination strategy adopted for ClearWaterPMPC.
These promotional tools have been spread at different platforms to spread awareness under the public. The project brochure was spread at several exhibitions to the public. Publications have been placed in several water related magazines, such as:
• Arab Water World (AWW) Magazine (Feb2013 Vol XXXVI Issue 2, pg. 21)
o Several responses have been received on this article from the middle east. Main replies came from the industry, looking to resell or commercialize the equipment locally.
• World Water (Vol 36, Issue 6, pg. 31-32) - Water Environment Federation.
o A few inquiries where received at our website, from the industry asking for more information about the system.
• Environmental-Expert.com
o This lead to many page views that could be tracked online.
o Inquiries came from the water industries to treat specific lakes within Europe.
o Some page-view notifications have also been received from municipalities and universities.
• World Water (Vol 36, Issue 6)
o A few inquiries where received at our website, from the industry asking for more information about the system.
• STREAM
• ClearWaterPMPC webpage, LG Sound B.V web-page.
A total of 20 events have been visited to disseminate the ClearwaterPMPC project. On these events promotional tools where spread, oral presentations where given, a workshop as organized or interviews where given to the local press.
• In total 8 exhibitions where visited in different countries in the world. Visited countries where Singapore, South Korea, Brazil, Spain, Japan, United Arab Emirates, UK and The Netherlands. Response from the different exhibitions came both from the general public, industry providers and municipalities.
o The main response from the municipalities was that this could be a very interesting product to solve algae blooms in drinking water reservoirs. In these applications the growth of algae causes problems with clogging of sand filters (in the water treatment plant) or with a bad taste and odour of the water, due to geosmins produced by cyanobacteria. A concern of many of the visitors from municipalities was how to protect the equipment from vandalism and birds.
o The main response on the project coming from the industry was very positive. Many people saw this as a good solution for drinking water reservoirs, lakes, recreational lakes but also industrial water and manmade lakes. Especially in the middle east, a lot of interest was generated in the sector of manmade lakes, as these lakes often have no ecological balance in place and no form of water treatment. Therefore, these lakes often suffer from severe algae blooms.
• Oral presentations where given at 2 conferences in the UK and in the United Arab Emirates. The average public at these seminars where between 25 and 70 persons. People attending the seminars where students, scientists and industry representatives and municipalities.
o The main response to the seminars came from scientist. Points of discussion with scientists where the ecological balance of a lake, and whether the ClearwaterPMPC system would disturb that. Other discussion points where the effect of ultrasound on zooplankton, such as Daphnia. These organisms are often referred to as a bio indicator for water quality, therefore it is important that they are kept alive. The release of toxins from cyanobacteria, once treated with ultrasound was also a point of discussion with scientists.
o Municipalities have approached us after the seminar with specific cases that might be interesting to the system.
• Workshops where organized by a company called Isle utilities. They have a Technology Approval Group, that is initiated by water and wastewater companies. Novel technologies are selected to present a workshop to these water companies. Main discussions at these workshops have been:
o The interest to set up trial locations for a Clearwater buoy at specific sites.
o Municipalities fear for a detrimental effect on the water quality and the balance within the ecosystem once algae are removed. This can result in lower oxygen levels, death of zooplankton etc.
o There is a doubt that the technology might increase toxin release of the cyanobacteria, once the ultrasound kills them and the cell ruptures.
o The fact was raised that the Clearwater system needs to be protected against vandalism and birds.
o Maintenance and installation where discussed.
• A 5 minute pitch and a 2 minute pitch where given at the Water Innovation Stimulation Award, organized by the Water Alliance in Amsterdam. The attendees where coming from Water companies, municipalities, universities and the industry. The main response at this event was:
o Water companies and municipalities claimed there is an occasional problem with blue-green algae in recreational lakes, but they do not have a direct intend to trial the ClearwaterPMPC technology.
List of Websites:
Project website address:
http://clearwater-pmpc.com/
Relevant contact details:
Coordinator
LG SOUND Nederland
Ing. Lisa Brand
Ba.Sc. (Biologist)
l.brand@lgsonic.com
www.lgsonic.com
For more contact details and project logo, please find attached file.
