PT Journal
AU Zeng, X
   Wu, P
   Su, S
   Bai, L
   Feng, Q
TI Phosphate has a differential influence on arsenate adsorption by soils with different properties
SO Plant, Soil and Environment
PY 2012
BP 405
EP 411
VL 58
IS 9
DI 10.17221/200/2012-PSE
DE isothermal equation; adsorption capacity; P/As molar ratio; As availability
AB 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<sup>(V)</sup>] adsorption capacities of six soils with different properties and the effects of P application were studied. The results indicated that the adsorbed As<sup>(V)</sup> contents all increased as a function of the As<sup>(V)</sup> content in equilibrium. When analysed using the Langmuir and Freundlich equations, the maximum As<sup>(V)</sup> 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<sup>(V)</sup> 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<sup>(V)</sup> 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<sup>(V)</sup> 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.
ER