The performance of UASB reactors treating high-strength wastewaters

In the study reported here, the authors investigated the influence of hydraulic loading rate, organic loading rate, and recycle rate on the performance of upflow anaerobic sludge blanket (UASB) reactors treating high-strength wastewaters. For this purpose, they used two identical reactors. The removal rates for chemical oxygen demand (COD), total kjeldahl nitrogen (TKN), total phosphorus (TP), total solids (TS), total suspended solids (TSS), and volatile solids (VS) were investigated for various hydraulic loading rates, and COD removal rates were investigated for various organic loading rates. In Reactor 1, a COD removal rate of 84.75 percent was achieved at influent COD of 8,000 mg/L and a hydraulic loading rate of 0.121 cubic meters per cubic meter per day (m3/m3-d). In Reactor 2, a COD removal rate of 82.83 percent was achieved at influent COD of 12,000 mg/L and a hydraulic loading rate of 0.069 m3/ m3-d. Although the COD removal rates of the reactors were high, TKN and TP removal rates were low. The removal rates usually decreased when hydraulic and organic loading rates were increased.