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Electrochemical Oxidation in the Recirculating Aquaculture Systems Industry

Periodic Reporting for period 3 - ELOXIRAS (Electrochemical Oxidation in the Recirculating Aquaculture Systems Industry)

Reporting period: 2017-12-01 to 2018-11-30

ELOXIRAS®: Boosting Recirculating Aquaculture Industry
Aquaculture industry appears to be an interesting alternative to fulfil the increasing global demand of marine species without spoiling natural resources. The aquaculture production within Europe offered 1.26 million tons of aquaculture products in 2015 (Eurostat), 70% of which came from marine areas. Recirculating aquaculture systems (RAS) are emerging as an advantageous technology to provide adequate culture water quality at inland hatchery and growing facilities. Since its introduction, RAS production has increased in volume and species with a 9.56% CAGR, and has a worldwide market estimated at 449.9 M€.
Although the RAS concept is an advantageous culture process that allows the control of key farming parameters, it requires high biomass densities to become profitable, which involves two important drawbacks: 1) a wide variety of pollutants as nitrogenous compounds (ammonia, nitrite and nitrate), organic matter and pathogens are generated due to fish excretion and decomposition of uneaten feed, implying fast accumulation of toxic metabolised compounds in low water volumes; 2) limited efficacy in the removal of these compounds by the conventional water treatment processes. Therefore, RAS end users require cost-efficient technologies able to deal with these key issues to boost their competitiveness. Market conventional water treatment technologies for RAS facilities are mainly based on bio-filtration and ozone, but they show efficacy fluctuations and start-up periods that increase the production stages and their costs. Based on an electrochemical oxidation technology, APRIA Systems is upgrading an innovative water treatment concept specially developed to improve the productivity of marine RAS used by the exponentially growing aquaculture industry – Electrochemical Oxidation in the Recirculating Aquaculture Systems Industry (ELOXIRAS: ELOXIRAS® allows the efficient removal of all the highly concerned pollutants in RAS, such as total ammonia nitrogen (TAN), nitrite, dissolved organic matter, bacteria and viruses, without the addition of chemicals or heat and with no change in water composition. Uniquely electricity and the catalytic properties of the electrode materials are required to achieve water purification.
ELOXIRAS project has been satisfactorily executed, making relevant progress in all WPs. The system has been optimized and upgraded before the pilot construction. Complementarily, re-engineering activities have led to a product with major versatility and minimum fails. Advances were done in pre and post-treatment requirements towards minimizing the CAPEX and OPEX. The certification assessment has revealed that ELOXIRAS requires CE marking for its distribution. Dissemination and exploitation of the product have been promoted thorough ELOXIRAS execution, at EU level and beyond (OTF programme), gaining the attention of several potential clients and stakeholders. But in the end, the aim of the project it to bring an innovative product to the market.
In this sense, great progress has been made on product definition and standardization. Four ELOXIRAS® series were defined regarding its market applications:
- MINI: designed for small-scale operations as hatcheries, large aquariums or R&D and innovation facilities.
- HYBRID: Ideal for large facilities.
- BIO: For quarantine and biosecurity operations.
- LOGISTIC: Designed to be integrated in transport platforms, such as trucks or well-boats, for live animals in logistic operations.

Complementarily, ELOXIRAS® is commercialized based on functionalities:
- Concept, provides the core functionalities of ELOXIRAS®.
- Basic, offers the entire ELOXIRAS® system with manual control, ideal for research purposes.
- Comfort, the equipment is fully automated.
- 4.0 with fully automated system, it also includes remote control via web browser.
Year 1 (1-12-month period)
- Design and manufacture the most optimised electrolysers in terms of technical performance and economic viability.
- Development of a mathematical model that describes the water treatment conditions and the upgraded ELOXIRAS® version.
- Preselection of 3 activated carbons that fulfil the ELOXIRAS® requirements.
- Detailed P&ID of the two prototypes and O&M manual.
- Procurement of the elements defined and included in the P&ID and construction of the two large-scale ELOXIRAS® prototypes.
- Assessment of certification requirements.
- Dissemination activities and exploitation of results.
- Project coordination.

Year 2 (13-24-month period)
- Package and shipment of both ELOXIRAS® prototypes from APRIA Systems facilities to
- Installation and start-up of both ELOXIRAS® prototypes in IRTA and RODECAN.
- Validation tests to assess and monitor ELOXIRAS® performance.
- Pilot testing of the different activated carbon (AC) filters selected in WP1.
- Re-engineering actions over the prototypes to improve the system performance.
- Demonstrative actions to assess the time evolution of nitrogenous compounds, the total chlorine and the biomass growth rate.
- Dissemination activities and exploitation of results.
- Development of data for a business plan.
- Project coordination.

Year 3 (25-36-month period)
- Validation and demonstration tests to assess and monitor ELOXIRAS® performance.
- Pilot testing of the different activated carbon (AC) filters selected in WP1.
- Re-engineering actions over the prototypes to improve the system performance.
- Study middle-long term effects of ELOXIRAS® on culture biomass.
- Dissemination activities and exploitation of results.
- Development of a complete business plan.
- Project coordination.
ELOXIRAS® prototypes have reached an excellent water quality, removing pollutants and keeping the key parameters at optimal values according to literature. The specific industrial-technological objectives beyond state of the art achieved are:
- The tests conducted confirm that ELOXIRAS® can remove TAN with an efficacy higher than 90%. Additionally, high removal efficacies of nitrites (90%), nitrates (50%) and organic matter have been observed.
- By increasing the biomass density, ELOXIRAS® can increase the production at least an 80% in pre-growing and a 40% in ongrowing, while maintaining the farming performance in relation to feeding and fish growth in comparison with typical values.
- Easy to operate, fitting perfectly the changes of the production.
- Compared to conventional RAS circuits, ELOXIRAS® entails a minimum of 50% reduction in the water intake, thus fulfilling the proposed target value of 20%.
- The power consumption of the electrochemical treatment observed in the end-user’s tests was lower than 4.4 kWh/kg feed/day in all instances.
- No need for an additional dedicated denitrification treatment. The monitoring of nitrates, verified by an external laboratory, showed that not significant accumulation is observed.
- High disinfection capacity. The microbiological analyses performed confirm that a disinfection capacity greater or equal to 3 log CFU/mL is likely to be achieved under treatment with ELOXIRAS®.
- No generation of by-products.
- Electrodes lifetime period equivalent to at least 2 years. MAGNETO claims that a 2-year electrode lifespan is guaranteed when the proposed CIS electrochemical cell is used, and a multiple-pass chemical cleaning protocol is implemented.
ELOXIRAS prototype A
ELOXIRAS concept
ELOXIRAS reactor
ELOXIRAS prototype B