Sulphate Reduction in a Three-Stage Packed-Bed Anaerobic Bioreactor

In this paper the effect of the sulphate concentration on the performance of a three-stage anaerobic baffled packed-bed reactor (ABPR) was investigated. Synthetic wastewater (3000 mg COD/l) was used as the sole organic substrate. The 30 liters fixed-bed bioreactor filled with plastic packing and divided in three equal sections was used as the mABPR reactor. The unit was run at a hydraulic retention time (HRT) of 1 day and at temperature of 25° C. The results of this study showed that when COD/SO4^2– ratios were changed from 30 to 3 with increasing sulphate concentration from 100 to 1000 mg/l, COD removal slightly was decreased. Maximum COD and sulphate removal were 91 and 96%, respectively, where more than 50% of this removal occurred in first compartment in the whole experiment. Overall sulphate concentration had little effect on the efficiency of organic removal and the anaerobic reactor performed well under various conditions, tolerating high concentration of sulphate.