Phosphate has a differential influence on arsenate adsorption by soils with different properties
X. Zeng, P. Wu, S. Su, L. Bai, Q. Fenghttps://doi.org/10.17221/200/2012-PSECitation:Zeng X., Wu P., Su S., Bai L., Feng Q. (2012): Phosphate has a differential influence on arsenate adsorption by soils with different properties. Plant Soil Environ., 58: 405-411.
The adverse effect of the application of phosphorus (P) on arsenic (As) adsorption by soils can result in increasing mobility and availability of As. However, in different soils, P might influence As adsorption differently. In this study, the arsenate [As(V)] adsorption capacities of six soils with different properties and the effects of P application were studied. The results indicated that the adsorbed As(V) contents all increased as a function of the As(V) content in equilibrium. When analysed using the Langmuir and Freundlich equations, the maximum As(V) adsorption capacity of 0.72 mg/g was found for an Alumi-Plinthic Acrisol, while the minimum capacity of 0.09 mg/g was observed for an Epigleyic Cambisol. The adverse effects of P application on As(V) adsorption by the six soils were observed to be variable. When the P/As molar ratio in a culture experiment was increased from 0 to 10, the maximal and minimal decreases in the As(V) adsorption capacity of 0.086 and 0.014 mg/g were found in the Alumi-Plinthic Acrisol and Epigleyic Cambisol, respectively. P was relatively more effective in competing for adsorption sites with As(V) in the Alumi-Plinthic Acrisol and Luvi-Endogleyic Phaeozem due to their higher A/P values (decrease in adsorbedKeywords:
As/added P) of 1.143 and 1.135, respectively. These results will help decrease the environmental risk of some As-contaminated agricultural soils through the controlled application of P.
isothermal equation; adsorption capacity; P/As molar ratio; As availability