Enhanced dewaterability of textile dyeing sludge using micro-electrolysis pretreatment. (15th September 2015)

• Record Type: Journal Article
• Authors: Ning, Xun-an; Wen, Weibin; Zhang, Yaping; Li, Ruijing; Sun, Jian; Wang, Yujie; Yang, Zuoyi; Liu, Jingyong
• Is Part Of: Journal of environmental management. Volume 161(2015)
• Page Start: 181
• Page End: 187
• Publication Date: 2015-09-15
• Subjects: Textile dyeing sludge -- Micro-electrolysis -- Dewaterability -- Extracellular polymeric substances -- Sludge disintegration; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2015.06.041
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: The effects of micro-electrolysis treatment on textile dyeing sludge dewatering and its mechanisms were investigated in this study. Capillary suction time (CST) and settling velocity (SV) were used to evaluate sludge dewaterability. Extracellular polymeric substances (EPS) concentration and sludge disintegration degree (DDSCOD ) were determined to explain the observed changes in sludge dewaterability. The results demonstrated that the micro-electrolysis could significantly improve sludge dewaterability by disrupting the sludge floc structure. The optimal conditions of sludge dewatering were the reaction time of 20 min, initial pH of 2.5, Fe/C mass ratio of 1/1, and the iron powder dosage of 2.50 g/L, which achieved good CST (from 34.1 to 27.8 s) and SV (from 75 to 60%) reduction efficiency. In addition, the scanning electron microscope (SEM) images revealed that the treated sludge floc clusters are broken up and that the dispersion degree is better than that of a raw sludge sample. The optimal EPS concentration and DDSCOD to obtain maximum sludge dewaterability was 43–46 mg/L and 4.2–4.9%, respectively. The destruction of EPS was one of the primary reasons for the improvement of sludge dewaterability during micro-electrolysis treatment. Highlights: Micro-electrolysis treatment was first applied to textile dyeing sludge. The dewaterability of textile dyeing sludge was significantly improved by micro-electrolysis. The optimal EPS concentration and DDSCOD were beneficial for obtaining maximum sludge dewaterability.