Treatment of High Strength Vegetable Processing Wastewater with a Sequencing Batch Reactor

Abstract

The feasibility of an aerobic sequencing batch reactor was studied at the lab scale to treat the high organic loading present in two vegetable processing wastewaters. Hydraulic retention time (HRT) was varied to evaluate its effect on the removal efficiency of chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN) and total phosphorus (TP). The results showed that a longer HRT promoted the removal of TP, while the liquid drawn per cycle had a larger effect on the COD removal efficiency. An increase in the COD/TKN and TKN/TP ratio decreased the removal efficiency of TKN and TP respectively. The optimized configuration was able to reduce the wastewater loadings to acceptable sewer discharge limits, making it possible eliminate the sewer surcharge fees.