Arsenic speciation dynamics in paddy rice soil-water environment: sources, physico-chemical, and biological factors - a review

Kumarathilaka, Prasanna and Seneweera, Saman and Meharg, Andrew and Bundschuh, Jochen (2018) Arsenic speciation dynamics in paddy rice soil-water environment: sources, physico-chemical, and biological factors - a review. Water Research, 140. pp. 403-414. ISSN 0043-1354

Abstract

Rice is the main staple carbohydrate source for billions of people worldwide. Natural geogenic and anthropogenic sources has led to high arsenic (As) concentrations in rice grains. This is because As is highly bioavailable to rice roots under conditions in which rice is cultivated. A multifaceted and interdisciplinary understanding, both of short-term and long-term effects, are required to identify spatial and temporal changes in As contamination levels in paddy soil-water systems. During flooding, soil pore waters are elevated in inorganic As compared to dryland cultivation systems, as anaerobism results in poorly mobile As(V), being reduced to highly mobile As(III). The formation of iron (Fe) plaque on roots, availability of metal (hydro)oxides (Fe and Mn), organic matter, clay mineralogy and competing ions and compounds (PO43− and Si(OH)4) are all known to influence As(V) and As(III) mobility in paddy soil-water environments. Microorganisms play a key role in As transformation through oxidation/reduction, and methylation/volatilization reactions, but transformation kinetics are poorly understood. Scientific-based optimization of all biogeochemical parameters may help to significantly reduce the bioavailability of inorganic As.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Files associated with this item cannot be displayed due to copyright restrictions.
Faculty/School / Institute/Centre: Current - Faculty of Health, Engineering and Sciences - School of Civil Engineering and Surveying
Date Deposited: 05 Feb 2019 00:11
Last Modified: 13 May 2019 00:18
Uncontrolled Keywords: Irrigation water; Geogenic arsenic; Redox chemistry; Arsenic speciation; Metal (hydro)oxides; Arsenic accumulation
Fields of Research : 05 Environmental Sciences > 0502 Environmental Science and Management > 050205 Environmental Management
Socio-Economic Objective: B Economic Development > 82 Plant Production and Plant Primary Products > 8204 Summer Grains and Oilseeds > 820402 Rice
Identification Number or DOI: 10.1016/j.watres.2018.04.034
URI: http://eprints.usq.edu.au/id/eprint/34916

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