ANAEROBIC TREATMENT OF SWINE WASTE BY THE ANAEROBIC SEQUENCING BATCH REACTOR

Anaerobic sequencing batch reactor (ASBR) uses a high-rate anaerobic b ioconversion process to stabilize organic wastes for odor control and generate biogas for energy use. It is well suited for treating animal wastes. This article reviews previous research on the ASBR and reporte d a laboratory study to evaluate the ASBR with swine waste at short hy draulic retention times (HRTs) (two, three, and six days), over a wide range of volatile solids loading rate (0.9 to 5.5 g/L/day) and at 25 degrees C. The ASBR demonstrated satisfactory performance at all three HRTs. The three-day HRT reactor showed the best overall performance i n terms of biomass settleability, biogas production rate, and reductio ns of volatile solids and biochemical oxygen demand in the manure afte r the treatment. In the intermediate range of VS loading rate (1.6-4.5 g/L/day), the VS reduction was 55 to 61%, BOD5 reduction was 81 to 86 % and biogas production rate was 0.9 to 1.8 L/L/day. it was found that ammonia did not adversely affect the performance of the ASBR at a con centration as high as 2470 mg/L in a pH range of 6.8 to 7.4. The ASBR can be easily integrated into a waste management system on a swine far m. The conceptual designs for the configurations and operational schem es of the ASBR system for working with swine confinement operations us ing flushing, scraping, or gravity draining (pull-plug) systems are pr esented.