Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA, Australia; CRC for Contamination Assessment and Remediation in the Environment, University of South Australia, Mawson Lakes, SA, Australia.
Sci Total Environ. 2013 Oct 1;463-464:1154-62. doi: 10.1016/j.scitotenv.2013.04.016. Epub 2013 Apr 29.
Phosphorus (P) influences arsenic (As) mobility and bioavailability which depends on the charge components of soil. The objective of this study was to examine P-As interaction in variable-charge allophanic soils in relation to P-induced As mobilization and bioavailability. In this work, the effect of P on arsenate [As(V)] adsorption and desorption was examined using a number of allophanic and non-allophanic soils which vary in their anion adsorption capacity. The effect of P on As uptake by Indian mustard (Brassica juncea L.) plants was examined using a solution culture, and a soil plant growth experiment involving two As-spiked allophanic and non-allophanic soils which vary in their anion adsorption capacity, and a field As-contaminated sheep dip soil. Arsenate adsorption increased with an increase in the anion adsorption capacity of soils. The addition of P resulted in an increase in As desorption, and the effect was more pronounced in the case of allophanic soil. In the case of both As-spiked soils and field contaminated sheep-dip soil, application of P increased the desorption of As, thereby increasing its bioavailability. The effect of P on As uptake was more pronounced in the high anion adsorbing allophanic than low adsorbing non-allophanic soil. In the case of solution culture, As phytoavailability decreased with increasing concentration of P which is attributed to the competition of P for As uptake by roots. While increasing P concentration in solution decreased the uptake of As, it facilitated the translocation of As from root to shoot. The net effect of P on As phytoavailability in soils depends on the extent of P-induced As mobilization in soils and P-induced competition for As uptake by roots. The P-induced mobilization of As could be employed in the phytoremediation of As-contaminated sites. However, care must be taken to minimize the leaching of As mobilized through the P-induced desorption, thereby resulting in groundwater and off site contamination.
磷（P）影响砷（As）的迁移性和生物可利用性，这取决于土壤的电荷组成。本研究的目的是研究变电荷层状土壤中 P-As 的相互作用，以及 P 诱导的 As 迁移和生物可利用性。在这项工作中，使用多种层状和非层状土壤研究了 P 对砷酸盐[As(V)]吸附和解吸的影响，这些土壤的阴离子吸附能力不同。使用溶液培养和涉及两种阴离子吸附能力不同的砷污染层状和非层状土壤的田间植物生长实验，以及田间污染绵羊浸出土壤，研究了 P 对印度芥菜（Brassica juncea L.）植物吸收 As 的影响。砷酸盐吸附随土壤阴离子吸附能力的增加而增加。添加 P 会导致 As 解吸增加，在层状土壤中效果更为明显。对于两种砷污染土壤和田间污染绵羊浸出土壤，施用 P 会增加 As 的解吸，从而增加其生物可利用性。P 对 As 吸收的影响在高阴离子吸附层状土壤中比低吸附非层状土壤中更为明显。在溶液培养中，As 的植物可利用性随 P 浓度的增加而降低，这归因于 P 与根对 As 的竞争。虽然溶液中 P 浓度的增加会减少 As 的吸收，但它有利于 As 从根部向地上部的转运。土壤中 P 对 As 植物可利用性的净效应取决于土壤中 P 诱导的 As 迁移程度以及 P 诱导的根对 As 吸收的竞争程度。P 诱导的 As 迁移可用于受污染场地的植物修复。但是，必须注意尽量减少通过 P 诱导的解吸而迁移的 As 的淋失，从而导致地下水和场外污染。
