Evaluation of biotoxicity of iron-carbon micro-electrolysis treatment of printing and dyeing wastewater by E.coli

The composition of printing and dyeing wastewater is complex, with high chroma and strong toxicity. By analyzing the morphology, antioxidant enzymes and biomarkers of E. coli (Escherichia coli), the biological toxicity of printing and dyeing wastewater before and after treatment with iron-carbon micro-electrolysis process was studied. The results showed that E.coli cells were broken in the influent and most of E.coli cells were in normal shape in the effluent. Compared with the influent, antioxidant enzyme, malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), and total antioxidant ability (T-AOC) in the effluent group decreased by 80.85%, 53.73%, 67.74%, 44.90% and 43.38%, respectively. After the printing and dyeing wastewater was treated by the iron-carbon micro-electrolysis process, its toxicity was reduced and the antioxidant system of E.coli was nearly in normal level. The glucose consumption inhibition rates of the influent and the effluent were 85% and 47%, respectively. Compared with the influent group, calorific value increased by 21.95%, endogenous fluorescent protein increased by 112.96%, and nucleic acid content decreased by 44.04% in effluent wastewater, respectively. Therefore, the iron-carbon micro-electrolysis process could reduce the biological toxicity of dyeing wastewater. © 2020, Chemical Industry Press Co., Ltd. All right reserved.