High grit content has been widely found in sludge of wastewater treatment plants in China.This paper investigated the effects of grit content(15％,30％,45％and 60％)on volatile fatty acids(VFAs)production during sludge alkaline fermentation.Results showed that the increase of grit content inhibited the sludge hydrolysis and acidification.VFAs concentration decreased from(314.0±11.93)mg CODCr/(g VSS)to(257.1±12.34)mg CODCr/(g VSS)as the grit content increased from 15％to 60％.With the increase of grit content,the concentration of soluble protein decreased from(75.83±2.79)mg/(g VSS)to(58.40±0.90)mg/(g VSS).The fluorescence intensity of tryptophan-like and aromatic protein-like substances,and the concentration of low molecular weight(＜1 kDa)soluble protein decreased with the increase of grit content.Meanwhile,the abundance of hydrolytic acidification bacteria such as Firmicutes,Proteobacteria and Acinetobacter also decreased with the increase of grit content.These findings resulted in the decrease of VFAs production.This study provides guiding significance for the optimized operation of alkaline fermentation system for VFAs production of sludge with high grit content.
维普
万方数据