title: Efficient remediation of pentachlorophenol contaminated soil with tetrapolyphosphate washing and subsequent ZVI/Air treatment.
abstract: In this study, we demonstrate that pentachlorophenol contaminated soil can be efficiently remediated with tetrapolyphosphate washing and subsequent zerovalent iron (ZVI)/Air treatment. 2 mmol L(-1) of tetrapolyphosphate could wash away 52.8% of pentachlorophenol (PCP) at pH 7.0 and 84.2% of pentachlorophenol at pH 11.0 from contaminated soil owing to the promotion effect of tetrapolyphosphate on the soil matrix dispersion and the subsequent solubilization of pentachlorophenol. More importantly, tetrapolyphosphate ions remained in the washing effluent could greatly enhance the molecular oxygen activation by ZVI to oxidize the desorbed PCP without any pH adjustment, and also avoid the competitive consumption of reactive oxygen species, as caused by the common organic surfactants in the washing effluent. Therefore, 85.1% of pentachlorophenol could be aerobically removed from the washing effluent by merely using 5 g L(-1) of ZVI. We also interestingly found that the dissolved iron ions released from the soil could enhance the oxidation of pentachlorophenol in the washing effluent, but the dissolved organic matter had the opposite effect. This study suggests the coupling tetrapolyphosphate washing and subsequent ZVI/Air treatment is an optional approach to remediate pentachlorophenol contaminated soil in view of its low cost and environmental benign.
authors.affiliation: Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental Chemistry, College of Chemistry, Central China Normal University, Wuhan 430079, PR China.
authors.forename: Menghua
authors.initials: M
authors.lastname: Cao
authors.affiliation: Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental Chemistry, College of Chemistry, Central China Normal University, Wuhan 430079, PR China.
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.affiliation: Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental Chemistry, College of Chemistry, Central China Normal University, Wuhan 430079, PR China. Electronic address: jennifer.ai@mail.ccnu.edu.cn.
authors.forename: Zhihui
authors.initials: Z
authors.lastname: Ai
authors.affiliation: Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental Chemistry, College of Chemistry, Central China Normal University, Wuhan 430079, PR China. Electronic address: zhanglz@mail.ccnu.edu.cn.
authors.forename: Lizhi
authors.initials: L
authors.lastname: Zhang
mesh_terms: D052918:Environmental Restoration and Remediation; D010084:Oxidation-Reduction; D010416:Pentachlorophenol / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry*; D012989:Soil Pollutants / Q000737:chemistry*; D012995:Solubility
chemical_list: D010710:Phosphates; D012989:Soil Pollutants; D010416:Pentachlorophenol
keywords: Molecular oxygen activation; Pentachlorophenol; Soil washing; Tetrapolyphosphate; Zerovalent iron