title: Potential phosphorus and arsenic mobilization from Bangladesh soils by particle dispersion.
abstract: Besides dissolution, particle dispersion and mobilization can substantially contribute to element transfer from soils to waters. The dispersibility of the fine particulate and the associated potential losses of P and As from Bangladesh soils of the Ganges and Meghna floodplains have been evaluated with a simple dispersion test. The dispersible fraction was greater for the coarse-textured soils from the Meghna floodplain and increased with particle charge density. Particulate phosphorus (PP) and As (PAs) were the dominant forms in the dispersion, dissolved P and As being scarce to negligible. The PP and PAs were related to the amount of dispersed particulate, oxalate-extractable iron and, respectively, to the water-extractable P or phosphate-extractable As. Although reductive dissolution is reported as the main mechanism of As mobilization during prolonged monsoon flooding, the transfer in particulate form could potentially represent a major pathway for P and As transfer from soils to waters in oxic environments after sudden, extreme events. Since the frequency of extreme rainfall and floods is increasing because of the climate changes, and the intensified land cultivation is enhancing soil disturbance, larger contributions of particulate runoff to element migration from soils to waters could be expected in the future.
authors.affiliation: Department of Agricultural, Forest and Food Sciences (D.I.S.A.F.A.), University of Torino, Largo Braccini, 2, 10095 Grugliasco, Torino, Italy. Electronic address: maria.martin@unito.it.
authors.forename: Maria
authors.initials: M
authors.lastname: Martin
authors.affiliation: Department of Agricultural, Forest and Food Sciences (D.I.S.A.F.A.), University of Torino, Largo Braccini, 2, 10095 Grugliasco, Torino, Italy; NATRISK, University of Torino, Largo Braccini, 2, 10095 Grugliasco, Torino, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Stanchi
authors.affiliation: Department of Agricultural, Forest and Food Sciences (D.I.S.A.F.A.), University of Torino, Largo Braccini, 2, 10095 Grugliasco, Torino, Italy; Bangladesh Water Development Board, Ministry of Water Resources, Dhaka 1000, Bangladesh.
authors.forename: K M
authors.initials: KM
authors.lastname: Jakeer Hossain
authors.affiliation: Bangladesh Australia Centre for Environmental Research, Department of Soil, Water and Environment, University of Dhaka, Dhaka 1000, Bangladesh.
authors.forename: S M
authors.initials: SM
authors.lastname: Imamul Huq
authors.affiliation: Department of Agricultural, Forest and Food Sciences (D.I.S.A.F.A.), University of Torino, Largo Braccini, 2, 10095 Grugliasco, Torino, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Barberis
mesh_terms: D001151:Arsenic / Q000032:analysis*; D001459:Bangladesh; D004784:Environmental Monitoring; D008956:Models, Chemical; D010758:Phosphorus / Q000032:analysis*; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis*
chemical_list: D012987:Soil; D012989:Soil Pollutants; D010758:Phosphorus; D001151:Arsenic
keywords: Arsenic; Bangladesh; Dispersion; Particulate; Phosphorus; Soil