Operational Characteristics of an Anaerobic Baffled Reactor Treating Low Strength Wastewater

A bench-scale experiment has been carried out to investigate the operational characteristics of a 9.9L anaerobic baffled reactor (ABR) treating low strength wastewater (about 500 mg COD/L) under mesophilic temperatures in term of chemical oxygen demand (COD) concentration, volatile fatty acids (VFA) concentration, pH value. The reactor was efficient in the removal of COD, viz. above 80%. The hydraulic load played an important role. Large part of COD was removed in the front compartments, which indicated a less compartment number would be suitable. The separation of acidogenic and methanogenic processes existed in the ABR after long-term operation. The results indicated that the performance of system could be recovered within 4 h after a 350% hydraulic shock for 2.5 h. The influence of organic shock load was complicated. The performance of system could be recovered within 8 h after 50% and 100% organic shock loads. Under the definition scope of low strength wastewater (COD<1000 mg/L), increasing organic shock loads would not deteriorate the performance of ABR. The compartmental structure of ABR provided its strong ability to resist shock loads. No granules were observed.