Study on efficiency and mechanism of iron-carbon microelectrolysis treatment of dyeing wastewater

Aiming at the problems of high chroma, complex composition, and difficult degradation of printing and dyeing wastewater, the iron-carbon micro-electrolysis process is used to treat the wastewater to improve its biodegradability and treatment efficiency. The effect of initial pH, iron dosage, iron/carbon mass ratio and reaction time on the treatment efficiency of dyeing wastewater was investigated. Scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (EDS) and X-ray diffractometry (XRD) were used to analyze the changes in the compositions of iron and carbon before and after the treatment of dyeing wastewater. Zeta potential and UV-Vis spectra were used to compare the changes of organic matter before and after wastewater treatment, and the degradation mechanism of dyeing wastewater was explored. Under the initial pH 4, the iron dosage of 80 g/L, the iron-carbon molar ratio of 0.8 and the reaction time of 90 min, the removal efficiencies of COD, turbidity, chroma, ammonia nitrogen and TOC were 75.48%, 87.88%, 75.34%, 92.01% and 81.09%, respectively. Before the treatment of dyeing wastewater, the composition of the iron-carbon reactor was mainly composed of iron and carbon, and the pore structure of the activated carbon was developed. After the reaction, the surface of the iron carbon adhered to other metal substances such as Al, K and the hydroxide flocs of iron. The iron-carbon micro-electrolysis process can degrade esters, alcohols and organic substances, decompose macromolecular substances and improve the biodegradability of wastewater. © All Right Reserved.