Sequential vertical flow trickling filter and horizontal flow multi-soil-layering reactor for treatment of decentralized domestic wastewater with sodium dodecyl benzene sulfonate

Sequential vertical flow trickling filter and horizontal flow multi-soil-layering bioreactor were investigated for the treatment of decentralized domestic wastewater at various concentrations of sodium dodecyl benzene sulfonate (SDBS). Results have shown that the removal rate of COD could reach 92.1% at initial COD concentration of 960 mg/L (800 mg/L was provided by SDBS). NH4+-N concentration could be reduced from 52.4 to 9.71 mg/ L without aeration. Besides, a quadratic function model was fit to describe the relationship between the relative activity of amylase and the protein content in extracellular polymer substance. SDBS could inhibit the transport and metabolisms of amino acids, lipids and carbohydrates in biofilms. The analysis of three-dimensional fluorescence diagram indicated that the peak in excitation/emission wavelengths = 310-340/370-430 nm was the characteristic peaks of some active substances such as some enzymes in EPS. Only Microbacterium could totally offset the toxicity of SDBS degradation products.