Textile Wastewater Treatment by Peroxydisulfate/Fe(II)/UV: Operating Cost Evaluation and Phytotoxicity Studies

Abstract

The discharges of the wastewater from the textile industry generate a substantial quantity of effluents which can cause various environmental problems, if disposed of without any prior treatment. Therefore, the treatment of these textile effluents is necessary. The present study aims to investigate the removal efficiency of colors from wastewater containing mixed primary direct dyes and real textile industry wastewater using PDS (Peroxydisulfate)/Fe(II)/UV process. A simulated mixture, based on an industrial recipe and containing Reactive Yellow 17 (RY17), Reactive Red 120 (RR120), and Reactive Blue 19 (RB19), was investigated. The obtained results showed that the mineralization rate is around 96.1% for RY17, 99.2% for RR120, 100% for RB19 and 80% for their mixed during 2 h of the treatment. The degradation of real textile wastewater was about 66% under similar conditions. The evaluations showed that ~ 93.82 MAD/m3 (~ 8.64 EURO/m3) is needed to supply the operating cost. As a vital industrial criterion, it was estimated that the conditions of initial pH of 3, [PDS] = 1 mM and T = 25 °C the highest cost effective case of the process for degrading the mixed dyes. Phytotoxicity studies revealed that the degradation products of mixed dyes and textile effluent were scarcely toxic in nature, thereby increasing the applicability of PDS/Fe(II)/UV for the treatment of textile wastewater. This will open a perspective for the reuse of treated water in crop irrigation. Based on the results of the advanced oxidation technologies experiments, it was found that PDS/Fe(II)/UV is the best treatment method for real textile wastewater.