Case Study 19: Marine Aquaculture Solid Waste Treatment
Principal Investigators: US: Kevin Sowers (University of Maryland); IS: Amit Gross (Ben Gurion University of the Negev)
Goal: To develop an integrated aquaculture wastewater treatment system for simultaneous microbial reduction of sludge mass, nitrate/nitrite removal, and biomethane production from varying organic loads throughout the fish growth cycle.
Activities: Laboratory studies to identify a marine methanogenic consortium and system factors influencing methanogenic activity.
Upscaling of laboratory reactors to a semi-commercial marine and brackish recirculating system with integrated modified large volume USAB (Upflow Anaerobic Sludge Blanket) bioreactors fed with saline sludge.
Outcomes: Development of a system that leads to an overall reduction of organic saline waste at inland mariculture farms, generates energy, and consequently leads to an improved system efficiency and a reduction in operating costs.
The first commercial application of a methanogenic consortium, developed by the US PI together with industry partners using the same principles developed in the BARD projects, was established at an inland salmon farm in Norway in 2018 to convert its salmon smolt solid waste into fuel-grade methane.
Economic Benefit: Net Present Value of BARD’s investment is $28 million. The Internal Rate of Return is 31%. Benefit-Cost Ratio is 44, thereof 1 already attained.
Capacity Building: 5 graduate students, 8 undergraduates and 1 high school student. 5 are currently in academia, of which 3 in the US, 1 in Israel and 1 in Armenia. Another 6 are in industry, of which 3 in the US and 3 in Israel.