Performance and Characteristics of Anaerobic Baffled Reactor Treating Soybean Wastewater

The performance and characteristic of a four compartment anaerobic baffled reactor (ABR) treating soybean wastewater were investigated. The effective volume of the reactor is 28 L. After inoculated with aerobic activated sludge of 18.0 g-L^-1 in the term of mixed liquor volatile suspend solid (MLVSS), the ABR started up at an organic loading rate (OLR) of 1.2 kg-(m³-d)^-1 with an influent COD of 2000 mg-L^-1 and a hydraulic retention time (HRT) of 39.5 hrs under a temperature of (35plusmn1)degC. The ABR reached a steady state after 23 days for the first time with a COD removal of 96%. Since the 32^nd day, the OLR increased to 6.0 kg-(m³-d)^-1 step by step through increasing COD of the feed at the same HRT 39.5 hrs and temperature (35plusmn1)degC. Based on the analysis of liquid fermentation products, namely volatile fatty acids (VFAs), the microorganism communities showed an observable difference among the four compartments. The phase separation of different microorganism communities made the ABR have good operation stability to shock loads. When the OLR increased to 3.0, and then to 4.8 and to 6.0 kg-(m³-d)^-1, the COD removal could always keep above 97%.