title: Impact of wastewater derived dissolved organic carbon on reduction, mobility, and bioavailability of As(V) and Cr(VI) in contaminated soils.
abstract: In this work, the effects of various wastewater sources (storm water, sewage effluent, piggery effluent, and dairy effluent) on the reduction, and subsequent mobility and bioavailability of arsenate [As(V)] and chromate [Cr(VI)] were compared using both spiked and field contaminated soils. Wastewater addition to soil can increase the supply of carbon, nutrients, and stimulation of microorganisms which are considered to be important factors enhancing the reduction of metal(loid)s including As and Cr. The wastewater-induced mobility and bioavailability of As(V) and Cr(VI) were examined using leaching, earthworm, and soil microbial activity tests. The rate of reduction of As(V) was much less than that of Cr(VI) both in the presence and absence of wastewater addition. Wastewater addition increased the reduction of both As(V) and Cr(VI) compared to the control (Milli-Q water) and the effect was more pronounced in the case of Cr(VI). The leaching experiment indicated that Cr(VI) was more mobile than As(V). Wastewater addition increased the mobility and bioavailability of As(V), but had an opposite effect on Cr(VI). The difference in the mobility and bioavailability of Cr(VI) and As(V) between wastewater sources can be attributed to the difference in their dissolved organic carbon (DOC) content. The DOC provides carbon as an electron donor for the reduction of As(V) and Cr(VI) and also serves as a complexing agent thereby impacting their mobility and bioavailability. The DOC-induced reduction increased both the mobility and bioavailability of As, but it caused an opposite effect in the case of Cr.
authors.affiliation: Chemical Safety Division, Department of Agro-Food Safety, National Academy of Agricultural Science, Wanju-gun, Jeollabuk-do 55365, Republic of Korea.
authors.forename: Anitha
authors.initials: A
authors.lastname: Kunhikrishnan
authors.affiliation: Southern Cross GeoScience, Southern Cross University, P.O. Box 157, Lismore 2480, NSW, Australia.
authors.forename: Girish
authors.initials: G
authors.lastname: Choppala
authors.affiliation: Global Centre for Environmental Remediation, ATC Building, University of Newcastle, Callaghan 2308, NSW, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), University of Newcastle, Callaghan 2308, NSW, Australia. Electronic address: Balaji.Seshadri@newcastle.edu.au.
authors.forename: Balaji
authors.initials: B
authors.lastname: Seshadri
authors.affiliation: Global Centre for Environmental Remediation, ATC Building, University of Newcastle, Callaghan 2308, NSW, Australia.
authors.forename: Hasintha
authors.initials: H
authors.lastname: Wijesekara
authors.affiliation: Global Centre for Environmental Remediation, ATC Building, University of Newcastle, Callaghan 2308, NSW, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), University of Newcastle, Callaghan 2308, NSW, Australia.
authors.forename: Nanthi S
authors.initials: NS
authors.lastname: Bolan
authors.affiliation: Department of Chemistry, Higher Teacher Training College of the University of Yaounde, P.O. Box 47, Yaounde, Cameroon.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Mbene
authors.affiliation: Chemical Safety Division, Department of Agro-Food Safety, National Academy of Agricultural Science, Wanju-gun, Jeollabuk-do 55365, Republic of Korea.
authors.forename: Won-Il
authors.initials: WI
authors.lastname: Kim
mesh_terms: D001151:Arsenic / Q000737:chemistry / Q000493:pharmacokinetics*; D001682:Biological Availability; D002244:Carbon; D002840:Chromates / Q000737:chemistry / Q000493:pharmacokinetics; D002857:Chromium / Q000737:chemistry / Q000493:pharmacokinetics*; D006863:Hydrogen-Ion Concentration; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000737:chemistry / Q000493:pharmacokinetics*; D062065:Wastewater / Q000737:chemistry*
chemical_list: D001151:Arsenic; D002244:Carbon; D002840:Chromates; D002857:Chromium; D012987:Soil; D012989:Soil Pollutants; D062065:Wastewater; C074702:chromium hexavalent ion
keywords: Adsorption; Arsenate; Bioavailability; Chromate; Dissolved organic carbon; Reduction