Effect of mixed petrochemical wastewater with different effluent sources on anaerobic treatment: organic removal behaviors and microbial community.

Abstract

Petrochemical industrial effluent contains industrial wastewater from various manufacturing processes. The mixed treatment of these different petrochemical wastewater effluents may influence the organic removal performance of the anaerobic processes. In this study, three typical petrochemical effluents, including polyester (PE), polyethylene terephthalate, and purified terephthalic acid wastewater, were collected. The effect of the mixed petrochemical wastewater on the organic removal and microbial community structure was investigated in the anaerobic batch assays via spectroscopy and high-throughput sequencing. The organic removal efficiencies were similar (71-85%) in all the batch assays for 90 h acclimation. The mixture of wastewater, especially the addition of PE wastewater, significantly prolonged organic removal process. It was related to the aromatic removal performance and microbial community structure during the mixed wastewater treatment. The microbial community structure in the mixed wastewater batch assay showed high similarity with that in the PE wastewater batch assay. Ignavibacterium, Syntrophus, and Pelotomaculum were crucial to the degradation of aromatic compounds together with Methanosaeta. The mixture of wastewater, especially the addition of PE wastewater, caused the decay of these functional microbes and resulted in the inefficient removal of the aromatic compounds.