Treatment of sludge from intensive whiteleg shrimp farming using a sequencing batch reactor

The wastewater/sludge generated from the shrimp aquaculture industry contains high levels of nitrogen (N), phosphorous (P), and carbon (C). This study aimed to evaluate the efficacy of N, P, and C removal and recovery from sludge obtained during the siphoning process of intensive white leg shrimp farming by using a sequencing batch reactor (SBR) with two trials. In the first trial, reactors were operated aerobically (3 - 5 days) and anaerobically (4 - 6 days) in sequence, resulting in a total cycle time of 9 days. In trial 2, the reactors were run aerobically for the first 3, 4, & 5 days, respectively, succeeded by anoxic conditions until the end of the experiment on day 14. The results showed that the removal of total ammonia nitrogen and chemical oxygen demand was about 60 - 70%, but the treatment efficiencies of total N and P were extremely low. Moreover, the anaerobic mode improved the mineralization of P, while aerobic condition promoted nitrate production. Further studies are needed to improve the nutrient and organic removal performance of the SBR.