Actavia 0 Zeng, X. Wu, P. Su, S. Bai, L. Feng, Q. 2012 2012-9-30 405-411 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 adsorbedAs/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. 9 58