Community Research and Development Information Service - CORDIS


SALTGAE Report Summary

Project ID: 689785
Funded under: H2020-EU.3.5.4.

Periodic Reporting for period 1 - SALTGAE (Demonstration project to prove the techno-economic feasibility of using algae to treat saline wastewater from the food industry.)

Reporting period: 2016-06-01 to 2017-11-30

Summary of the context and overall objectives of the project

For any industry generating vast amounts of wastewater, management of their residues required to comply with the EU directives involves direct costs which can be very high. This issue is critical for many industrial sectors, such as food processing, leather industries and land-based aquaculture, which generate saline wastewater. This kind of wastewater, with high concentrations of biodegradable organic matter, suspended solids, nutrients (mainly nitrogen and phosphorus) and salt (concentrations up to 15%), is extremely difficult and expensive to treat by conventional means (e.g anaerobic bacterial treatment is inhibited), making this cost unaffordable for SMEs, who can decide not to comply with EU directives and discharge without prior treatment, causing severe damage to the environment.
The objective of the SALTGAE project is twice:
1) Develop a techno-economically viable solution for the treatment of saline wastewaters from the Food and Beverage (and related) industry and implement and demonstrate it at large scale.
2) Develop an innovative platform for the mobilization and networking of stakeholders from all the different sectors related to wastewater, and for the dissemination of results with the aim of promoting paradigm shift in perception from ‘wastewater treatment’ to ‘resource valorisation’

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

The most important activities and results achieved in the first period are described next:

1. Selection and tests of the best performing algae-bacteria cultures for optimum BOD treatment efficiency suitable for different salinity and wastewater compositions.
2. Characterization of industrial wastewater and design of primary and pre-treatment processes. After testing, the dimensioning and detailed design for implementation in the Demos sites were done.
3. Anaerobic digestion treatment has been applied on saline wastewater to reduce their BOD load. Bacterial adaptation to high saline waste water has been successful and continuous test at lab scale have allowed to define the most important parameters for the scale-up to the Demo site.
4. Valorisation of effluents from algal treatment by assessment of best pre-treatment strategy for desalination (validated and optimized at pilot scale), electrodialysis for demineralisation of pre-treated effluents, creation of prototypes of a new pump for Reverse Osmosis and design of a device to recover the energy contained in the rejection stream, saving costs.
5. Biomass harvesting has been tested by combination of different techniques, including membrane technology and centrifugation. Good results have been reached so far.
6. The harvested biomass is submitted to refinement and extraction of its different. Both mechanical methods and chemical methods has been defined and extraction test at lab scale were performed for each of the type of algae.
7. Valorization of algal biomass fractions have been studied to produce new product, such as monomers for adhesives applications, water-based PU dispersions for coatings and adhesives, edible coatings, and high value material fillers & pastes.
8. Evaluation of the design and operational factors that influence high rate algae pond performance and cost efficiency, by mathematical model and CFD model.
9. Sensorization, monitoring and control of the high rate algae ponds, including functionality of the control system.
10. Scale-up of anaerobic digestion results to the Demo size and definition of the main equipment and the expected performance by means of modeling. Selection of the suppliers and on-site preparation to install the equipment.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

a. Innovative use of algal-bacterial treatment
The use of algal-bacterial system process not only eliminates the energy requirement of aeration (algae produce oxygen), but also partially embodies the energy contained in the wastewater into the biomass which can then be used for other purposes or to recover energy into biogas. As result, the treatment is much cheaper due to the reduced costs of aeration, CO2 is recycled rather than contributing to the climate change, and biomass can be further utilized (and sold).
b. Finding the most efficient bacteria that will treat wastewater with high salinity
Another important progress is development of a salt-tolerant anaerobic digestion. Archea are known to be salt sensitive and they cannot survive at elevated salinity levels. However, by means of the adaptation strategy and measures developed in the project this problem has overcome and biogas has been produced successfully at lab scale under high salinity.
Saltgae Project will develop an innovative modular based technology platform for the efficient treatment of saline wastewaters containing organic load, enabling ease of operation, significant cost reductions, compliance with European Directives with minimal environmental impact, recycling of water for non-potable applications and valorisation of nutrient and energy resources, with the following performance:
• Efficiency of BOD, N and P removal (> 90%) and algae biomass growth (> 15 g/m2/day)
• Able to deal with different salinity levels (2 g/L to 60 g/L) and wastewater compositions.
• Cost reduction > 40% with respect to current alternatives for saline wastewater with organic load.
• Able to valorise the algae biomass produced transforming the reject in revenue, with an increment of > 15% profit margin earned per tonne of algae biomass produced.
• Techno-economically viable, implemented and tested at DEMO scale in order to operate and validate them under real environment conditions and scale, and subjected to EU Environmental Technology Verification Program.
a) Resource efficiency and environmental performance.
Saltgae is aimed to produce less energy consumption, energy extraction from the wastewater, less green-house gas emissions, better effluent quality, significantly reducing industrial salt emissions and resource savings by valorisation of biomass. It also reduced the ammonium content of wastewater, preventing euthrophication. In additon, it is helping process industries become less water dependent while ensuring efficient management of other resources.
b) Creation of new market opportunities.
The valorisation of biomass via creation of edible coatings, the generation of know-how linked to improved formulations for animal feed and adhesives, the innovations related to the generation of biogas, a more energy efficient Reverse Osmosis desalination process or a more sustainable cycle of water-fish production-crop irrigation will enable sustainable economic growth, business and job creation both in the water sector and beyond.
c) Contribution to the implementation of the EIP Water across a number of key areas
SALTAGE project contributes to the objectives of EIP water across a number of key areas: 1) Water and wastewater treatment, including recovery of resources (by reduction of dissolved nutrients and recover them as biomass with potential source of high value precursors); 2) Water Reuse and Recycling (almost complete elimination of salt from water stream with > 20% of expected water recycling rate). 3) Water Energy Nexus (recovery of energy from the wastewater by conversion of BOD to heat and electricity); 4) Cross cutting challenges (mobilizing stakeholders and promoting paradigm shift in perception from ‘wastewater treatment’ to ‘resource valorisation’).

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