Insight into trichloroethene removal in alkaline condition with the presence of surfactant based on persulfate system. Issue 5 (October 2022)

• Record Type: Journal Article
• Authors: Xu, Zhiqiang; Cai, Lankun; Liang, Xue; Lyu, Shuguang
• Is Part Of: Journal of environmental chemical engineering. Volume 10:Issue 5(2022)
• Publication Date: 2022-10
• Subjects: Trichloroethene -- Sodium dodecyl sulfate -- Critical micelle concentration -- Persulfate -- Groundwater remediation; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2022.108492
• Languages: English
• ISSNs: 2213-2929

Abstract

Abstract: Trichloroethene (TCE) degradation was investigated in Fe(II)/citric acid (CA) activated persulfate (PS) system containing surfactant sodium dodecyl sulfate (SDS). Only 37.7% removal of TCE was achieved at PS/Fe(II)/CA/TCE molar ratio of 40/20/20/1 in the presence of 2.3 g L −1 SDS with pH unadjusted (pH = 2.96). However, this result was significantly increased to 81% after adjusting the initial solution pH = 9.0. The presence of SDS inhibited TCE degradation and this inhibitory effect was initially increased and then declined with SDS concentration increase from 0 to 9.2 g L −1 . Radical scavenger experiments revealed that the major reactive oxygen species (ROS) contributed to TCE degradation were HO and SO4 −, while less contribution was owed to O2 − . The intermediates of SDS were identified with GC-MS and possible decomposition pathway of SDS was proposed. The performance of TCE degradation in other solution matrixes were investigated. Actual groundwater tests showed that PS/Fe(II)/CA system possessed huge potential in remediating groundwater contaminated by TCE with SDS presence. This research found that alkaline condition was more favorable for TCE degradation in PS/Fe(II)/CA system in the presence of SDS and the possible reasons for this phenomenon were explored from various aspects. Graphical Abstract: ga1 Highlights: The influence of solution pH on the CMC value of SDS was investigated. The mechanism of higher TCE degradation in alkaline condition was explored. HO and SO4 − were the primary ROSs in PS/Fe(II)/CA system with the presence of SDS. Significant TCE degradation in actual groundwater containing SDS was achieved after adjusting solution pH = 9.