Improving anaerobic sequencing batch reactor performance by modifying operational parameters.

A lab-scale anaerobic sequencing batch reactor (ASBR) that had operated with glucose at an organic loading rate of 2.1 kg COD m(-3) d(-1) was stressed with an organic loading rate of 3.2 kg COD m(-3) (-1). Five different combinations of influent concentration, total cycle time, and fill time to cycle time ratio were examined. No external pH control was used. In all cases, acetate and propionate were the main constituents of the effluent. Larger fill time to cycle time ratios and lower initial substrate concentrations resulted in improved performance suggesting that ASBR operation may be improved by changing operational parameters.