123rd General Meeting of the KCS

Type Poster Presentation
Area Environmental Energy
Room No. Exhibition Hall 2
Time 4월 18일 (목요일) 11:00~12:30
Code ENVR.P-510
Subject Natural organic matter effects on the removal of mercury in groundwater by pumice-supported nanoscale zero-valent iron
Authors Qasim Ghulam Hussain, Seunghee Han1,*
School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology, Korea
1School of Environmental Sciences and Engineering, Gwangju Institute of Science and Technology, Korea
Abstract Previous studies have reported the outstanding Hg removal efficiency of nanosized zero-valent iron (nZVI), related to the reductive sorption of Hg(II). However, how natural organic matter (NOM) in contaminated water changes Hg removal has not been tested despite the ubiquitous presence of NOM in wastewater. To investigate the potential effects of NOM on Hg(II) removal by nZVI, a series of batch tests was carried out using a mixture of 250 nM of Hg(II) and 3.6 g L-1 of pumice-supported nZVI (p-nZVI) in the absence and the presence of 1, 10, and 100 mg L-1 of Suwannee River NOM (SRNOM). The 80 minuite tests showed that Hg(II) removal efficacy declines with increasing NOM concentration, and in the presence of 100 mg L-1 of NOM, headspace Hg(0) and Hg removal rate decrease from 23 to 12 µmol m-3 and from 89 to 36%, respectively. Similar trends were observed in the 15 day tests, attributable to surface passivation of p-nZVI by NOM. In contrast, adding 100 M of glutathione (GSH) to the mixture of Hg(II) and p-nZVI increased Hg(II) removal efficiency from 85 to 96% on day 15, attributable to the formation of Hg(II)-GSH complex that can be removed by ferric (i.e., lepidocrocite) surface of p-nZVI. Furthermore, adding GSH to the mixture of Hg(II), p-nZVI, and SRNOM effectively removed Hg(II), demonstrating the addition of thiolic organic compounds, likely to form oxidative complexes with Hg(II) and Hg(0), can be an effective way to overcome NOM inhibition effects in the application of nZVI for Hg(II) remediation.
E-mail qasimgh@gist.ac.kr