The Treatment Performance of an ABR-DHS System for Natural Rubber Wastewater

摘要

In this study, treatment performance of a combined system consisted of an anaerobic baffled reactor (ABR) and a down-flow hanging sponge (DHS) reactor (ABR-DHS system) was evaluated. Synthetic natural rubber processing wastewater was used for the experiment. The ABR-DHS system achieved a chemical oxygen demand (COD) removal efficiency of 98.5% with an organic loading rate of 3.1 kgCOD/(m~3•day). In addition, the DHS effluent achieved both Malaysian and Vietnamese (B) effluent standard of pH, COD, total nitrogen and ammonia concentration. In the ABR, 96.9% of volatile fatty acid (VFA) was removed and converted to methane. The estimated greenhouse gases (GHG) emission rate from the ABR was 0.00018 t-CO_(2c)/m~3-wastewater. In the results of microbial community analysis of the ABR retained sludge, Hydrogen-utilizing methanogen Methanobacterium (10.0 to 23.1%) was predominantly detected. Also, VFA oxidizing bacteria, Syntrophobacter (9.2 to 37.1%), Pelotomaculum (0.0 to 8.8%) and Syntrophomonas (0.4 to 1.7%), were detected. On the other hand, the abundance of acetate-utilizing methanogen Methanosarcina was low (0.5 to 1.4%). These results indicate that hydrogen-utilizing methanogen and VFA oxidizing bacteria contribute significantly to organic matter degradation in the wastewater.