Sequencing batch biofilm reactor (SBBR) for the treatment of effluents from Penaeus vannamei cultivated under biofloc conditions

Abstract

The present study evaluated two mechanically agitated 19 L-sequencing batch biofilm reactors (SBBRs) using low-cost biological support, oyster shells (R1) and plastic matrices filled with polyurethane foam (R2), for treating wastewater from intensive P. vannamei culture. The treatment process consisted of batches with a 7-day cycle that alternated phases without and with aeration. An SBBR for wastewater treatment was feasible. Ammon-N was reduced by approximately 93 % in both bioreactors, with effluents of 0.26 and 0.24 mg L−1, which were efficiently obtained after 6 and 24 h for R1 and R2, respectively. Nitrite was present at 0.03 mg L–1 in R1 and 0.0 mg L–1 in R2, whereas nitrate was not significantly reduced. Carbon reduction (measured as chemical oxygen demand (COD)) was observed in R2, with an efficiency of 84 %, an effluent value of 19 mg L–1, as well as phosphorus solubilization in both bioreactors. The results obtained in this study indicate that both support materials can be used in SBBR bioreactors to treat wastewater from shrimp farming.