Mao Ye; Sun Mingming; Yang Xinglun; Wei Haijiang; Song Yang; Xin Jiang. Remediation of organochlorine pesticides (OCPs) contaminated soil by successive hydroxypropyl-β-cyclodextrin and peanut oil enhanced soil washing–nutrient addition: a laboratory evaluation.Journal of soils and sediments 2013 13(2): 403-412 [10 page(s) (article)]

Abstract

PurposeProblems associated with organochlorine pesticides (OCPs)-contaminated sites have received wide attention. To address the associated environmental concerns innovative ex situ techniques are urgently needed.Materials and methodsAs regards long-term contamination by OCPs in Wujiang region China we investigated the feasibility of a cleanup strategy that employed hydroxypropyl-β-cyclodextrin (HPCD) and peanut oil to enhance ex situ soil washing for extracting OCPs followed by the addition of supplemental nutrients to the residual soil.Results and discussionElevated temperature (50 °C) in combination with ultrasonication (35 kHz 30 min) at 50 g L⁻¹ HPCD and 10 % peanut oil were effective in extracting and therefore washing the OCPs in soil. Ninety-three percent of total OCPs 98 % of dichlorodiphenyltrichloroethanes 93 % of chlordane as well as 85 % of Mirex were removed from soil after three successive washing cycles. Treating the residual soil with nutrients addition for 12 weeks led to significant increases (p < 0.05) in the average well color development obtained by the BIOLOG Eco plate assay Shannon–Weaver index Simpson index and EC₅₀ ecotoxicological evaluation compared with the controls. This implied that this cleanup strategy at least partially restored the microbiological functioning of the OCPs-contaminated soil and has the advantage of being an environmental-friendly technology.ConclusionsThe ex situ cleanup strategy through HPCD and peanut oil enhanced soil washing followed by nutrients addition could be effective in remediation of OCPs-contaminated soil.