title: Elemental sulfur amendment decreases bio-available Cr-VI in soils impacted by leather tanneries.
abstract: This study investigated the potential use of elemental S (S(0)) to convert Cr-VI to Cr-III which should decrease the bio-availability hence, toxicity of Cr-VI in soils. The bio-available fraction of Cr in soil was measured by phosphate buffer extraction (PBE) and the results showed that the fraction is about 10% of the total Cr-VI and varied from 12.8 to 42.5 mg kg(-1). The addition of 4.0 mg g(-1) S(0) decreased PBE Cr-VI to <0.4 mg kg(-1) limit established for Cr-VI toxicity in soils. Synchrotron-based X-ray absorption near-edge structure (XANES), X-ray fluorescence (XRF) and micro-XRD revealed that Cr-III was the dominant species (99% of total Cr) and Cr was retained by hematite and goethite in soil. Fe-containing minerals may have provided sufficient protection to render the dominant Cr-III species biochemically inert to redox processes in soils. It is concluded that S(0)amendment is a promising approach to remediate Cr-VI contaminated soils.
authors: College of Life and Environmental Sciences, Wenzhou University, Wenzhou, Zhejiang Province 325035, China; Environmental Science and Engineering Programs, University of Northern British Columbia, Prince George, BC V2N 4Z9, Canada. Electronic address: Jshi@unbc.ca.
authors: Jingjing
authors: J
authors: Shi
authors: College of Life and Environmental Sciences, Wenzhou University, Wenzhou, Zhejiang Province 325035, China. Electronic address: hualin2100@126.com.
authors: Hualin
authors: H
authors: Chen
authors: College of Life and Environmental Sciences, Wenzhou University, Wenzhou, Zhejiang Province 325035, China; Environmental Science and Engineering Programs, University of Northern British Columbia, Prince George, BC V2N 4Z9, Canada. Electronic address: Joselito.arocena@unbc.ca.
authors: Joselito M
authors: JM
authors: Arocena
authors: Environmental Science and Engineering Programs, University of Northern British Columbia, Prince George, BC V2N 4Z9, Canada. Electronic address: Todd.whitcombe@unbc.ca.
authors: Todd
authors: T
authors: Whitcombe
authors: College of Life and Environmental Sciences, Wenzhou University, Wenzhou, Zhejiang Province 325035, China; Environmental Science and Engineering Programs, University of Northern British Columbia, Prince George, BC V2N 4Z9, Canada. Electronic address: Ron.thring@unbc.ca.
authors: Ronald W
authors: RW
authors: Thring
authors: Environmental Science and Engineering Programs, University of Northern British Columbia, Prince George, BC V2N 4Z9, Canada. Electronic address: Nzememi@unbc.ca.
authors: Jeff Nze
authors: JN
authors: Memiaghe
mesh_terms: D002412:Cations; D002857:Chromium / Q000032:analysis*; D004787:Environmental Pollution; D010084:Oxidation-Reduction; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis*; D013455:Sulfur / Q000737:chemistry*; D013633:Tanning; D014965:X-Rays
chemical_list: D002412:Cations; D012987:Soil; D012989:Soil Pollutants; D002857:Chromium; D013455:Sulfur
keywords: Bio-available metals; Environmental risks; Synchrotron; X-ray diffraction