Regulation Methods and Enhanced Mechanism on the Efficient Degradation of Aromatics in Biochemical Treatment System of Coal Chemical Wastewater

In order to address the problems of poor treatment effect of coal chemical wastewater (CCW) biochemical treatment system resulting in non-compliance with effluent standards and unstable operation, a combination regulation method of co-substrate metabolism and predominant flora enhancement was constructed, and the performance and mechanism of enhanced degradation of aromatics in CCW was also investigated in this study. The results showed that when the influent concentration of chemical oxygen demand (COD) and aromatics was less than 600 mg/L and 180 mg/L respectively, there was no significant effect of the combined regulation method on the enhanced treatment of aromatics, the removal rate of total organic carbon (TOC) in the system could all more than 73%; while when the influent concentration of COD increased to 800 mg/L and the aromatics concentration increased to more than 240 mg/L, the ordinary activated sludge system had collapsed. Compared with the regulation method of co-substrate metabolism alone, the combination regulation method increased the removal rate of TOC by 21%. The mechanism of enhanced degradation of effective aromatics by the combination regulation method was clarified, the result showed that under the combination regulation method, the antioxidant system of the microorganisms was increased, and the bacterial genera for aromatics degradation was enhanced, the higher dehydrogenase activity of the microorganisms facilitated the removal of the aromatics. The study provides a theoretical basis and technical guidance for solving the problems of unstable operation of CCW biochemical treatment systems and non-compliance with effluent standards