Enhanced dewaterability of textile dyeing sludge using micro-electrolysis pretreatment

Xun-An Ning; Weibin Wen; Yaping Zhang; Ruijing Li; Jian Sun; Yujie Wang; Zuoyi Yang; Jingyong Liu

doi:10.1016/j.jenvman.2015.06.041

Enhanced dewaterability of textile dyeing sludge using micro-electrolysis pretreatment

J Environ Manage. 2015 Sep 15:161:181-187. doi: 10.1016/j.jenvman.2015.06.041. Epub 2015 Jul 13.

Authors

Xun-An Ning¹, Weibin Wen², Yaping Zhang³, Ruijing Li³, Jian Sun³, Yujie Wang³, Zuoyi Yang³, Jingyong Liu³

Affiliations

¹ School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China. Electronic address: ningxunan666@126.com.
² School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China. Electronic address: wenweibin0@sina.com.
³ School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China.

PMID: 26172108
DOI: 10.1016/j.jenvman.2015.06.041

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.

Keywords: Dewaterability; Extracellular polymeric substances; Micro-electrolysis; Sludge disintegration; Textile dyeing sludge.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

China
Electrolysis / methods*
Sewage / chemistry*
Textile Industry*
Waste Disposal, Fluid / methods*
Wastewater / chemistry*
Water Purification / methods*

Substances

Sewage
Waste Water