Treatment of fish processing wastewater with microalgae-containing microbiota

Two photobioreactors inoculated with microalgae from a lagoon containing aerobically treated swine slurry and with sludge from a membrane submerged bioreactor treating winery wastewater were established to treat fish processing wastewater (FPW) at 23 and 31 °C, respectively. The hydraulic retention time (HRT) was decreased in the photobioreactors from 10 to 5 days. Ammonium was completely exhausted in both photobioreactors; however, volatilization was the main removal mechanism for the highest applied load whereas biomass assimilation was the main mechanism for the lowest applied load. Approximately 70% of TCOD (total chemical oxygen demand) and phosphate removal was achieved regardless of temperature. Biomass productivity was as much as 55% higher at 31 °C than at 23 °C. These results suggested that fish processing wastewater could be effectively treated using this technology.