Aerobic treatment of fish canning wastewater using a pilot-scale external membrane bioreactor

Abstract

Fish canning wastewater is characterized by high salinity and organic matter, which makes its treatment particularly difficult. To this purpose, the use of an aerobic membrane bioreactor (AeMBR) process could be a perfect option for the treatment of this wastewater. The aim of this study was to evaluate the effect of different operational conditions on the performance of the biological process and ceramic ultrafiltration (UF) membrane in AeMBR pilot plant for fish canning wastewater treatment. The AeMBR pilot was operated under ambient conditions (21.5 °C), 12 days of sludge retention time (SRT) and for a hydraulic retention time (HRT) of 24 h. The effect of operational parameters including organic loading rate (OLR) (3–5 kg COD/m3.day); total dissolved solids (TDS) (2.5–5 g/L), oxygenation rate (700 and 1300 NL/h) and transmembrane pressure (TMP) (0.05–1.5 bar) affected the quality of the effluent. The main performance results were the removal of approximately 97% of COD, 98% of BOD, 90% of nitrate and over 97% of total Kjeldahl nitrogen (TKN) and total phosphorus (TP). The treated effluent at the output of the AeMBR meets the quality standards according to the Food and Agriculture Organization (FAO) directive and the Moroccan standards for the discharge and reuse of water for irrigation and watering.