Effects of Na2SO4 Concentration on Pollutants Removal and Mi-crobial Metabolic Characteristics in the Hydrolysis-Aerobic Treatment of Dyeing Wastewater

Chong-Miao Zhang, Yu-Chao Ma, Quan-Rui Niu, Zhe-Chao Wei, Peng-Kang Jin, Li-Mei Xu



Hydrolysis-aerobic biological treatment process shows low efficiency in removal inorganic salts from the dyeing wastewater, and the accumulation of inorganic salts in dyeing wastewater reuse process may inhibited the pollutants removal. To understandthis problem, a dyeing hydrolysis-aerobic biological treatment process was established, and the influence of interval increasing Na2SO4 concentration on treated effluent quality was investigated. Biolog technology was used to study the microbial metabolic characteristics under different Na2SO4 concentrations. The results indicated that the concentration of CODcr, NH4+-N and TP in the effluent increased as the increase of Na2SO4 concentration. When the Na2SO4 concentration in the influentincreased to 2700 mg/L, the concentration of CODcr and TP in sedimentation tank effluent was 2567.94 mg/L and 1.94 mg/L, respectively, which exceeded the requirement of effluent quality for printing and dyeing process. After 144 h, MLSS decreased to 1148 mg/L, while SV30 increased to78% with increasing salt content and sludge run off with the effluent. The system acclimated seed could tolerate a maximum shock of 2400 mg/L Na2SO4. The high Na2SO4 concentration would increase the ability of microbial community to utilize carbon source, especially the use of acids and saccharides.