US EPA

1579241 

Journal Article 

Phosphorus-arsenic interactions in variable-charge soils in relation to arsenic mobility and bioavailability 

Bolan, N; Mahimairaja, S; Kunhikrishnan, A; Choppala, G 

In Press 

Yes 

Science of the Total Environment
ISSN: 0048-9697
EISSN: 1879-1026 

463-464 

1154-1162 

English 

23639210 

10.1016/j.scitotenv.2013.04.016 

WOS:000325831200126 

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. 

Arsenic; Adsorption; Phosphorus; Variable-charge soil; Bioavailability