Recirculating aquaculture systems (RAS) provide a scalable fish growing technology with minimal water demand and a small areal footprint. Currently, massive aquaculture production via RAS is still impaired by the accumulation of fine suspended solids, and ammonia in the fish pond. Integration of bioreactors with membrane technology such as ultrafiltration was suggested to resolve the former constraints. However, the impact of RAS feedwater on the performance of ultrafiltration membrane is still unknown. This study investigated the impact of feedwater properties of RAS on biofouling propensity and performance of an inside-out hollowfiber ultrafiltration membrane. To this end, the permeate water flux and biofouling propensity of five membrane bioreactor systems were tested with different concentrations of fine suspended solids that range from 20 -150 mg l-1. The results indicated that 150 mg l-1 of fine suspended solids led to a 70% reduction in permeate water flux. Specifically, soluble microbial products and the extracellular polymeric substance led to greatest impact on permeate water flux. Overall, the results and corresponding insights highlight that the Ultra filtration membrane performance is limited by suspended solids concentration of the feed water, according to the experiment the suspended solids concentration in the RAS water should be maintain to 50 mg l-1 .these could serve as a basis for optimizing RASs for the sustainable production of aquatic products.
Mr. Mohammed Bream
Treatment of Intensive Fish Wastewater by Ultrafiltration: From Fouling Propensity to Membrane Performance
Ben Gurion University of the Negev, Israel