[Effect of phosphorus on arsenic adorption by three different soils]

The effect of phosphorus on arsenic adsorption by yellow soil, red soil and brown soil was studied using batch experiment. The results indicated that the arsenic without P amendment adsorption capacity of three tested soils was yellow soil > red soil > brown soil. The maximal adsorption capacity of yellow soil and red soil was decreased with 60 mg.kg-1 phosphorus added, and that of brown soil was increased with 20 mg.kg-1 phosphorus added. The arsenic adsorption capacity of three soils was greater when P: As = 1:2 than that when P: As = 1:1 and P: As = 2:1, and the differences between P: As = 1:1 and P: As = 2:1 treatments were not significant. Observations could be better fitted by Langmuir equations.