Assessing the phytoavailability of arsenic and phosphorus to corn plant after the addition of an acrylic copolymer to polluted soils.

Abstract

Soil pollution by arsenic increases the potential risk of arsenic entrance into the food chain. The usefulness of maleic anhydride- styrene- acrylic acid copolymer on the mobility and phytoavailability of arsenic was evaluated. Treatments were the concentrations of acrylic copolymer (0, 0.05, 0.10, and 0.20% w/w) and the concentrations of soil total arsenic (0, 6, 12, 24, 48, and 96mgkg-1). Sodium arsenate was added in appropriate amounts to subsamples of an uncontaminated soil to give contaminated soils with different levels of arsenic. The contaminated soils were subjected to a greenhouse experiment using corn as the test crop. The results showed that contamination of soil by arsenic increased the concentrations of soil available arsenic, root and aerial parts arsenic. By the use of acrylic copolymer, the concentration of available arsenic in the soil and the accumulation of arsenic in the root and aerial parts of the corn plant decreased but the dry weights of the root and aerial parts increased significantly. When the concentration of soil total arsenic was 96mgkg-1, the application of copolymer at the concentration of 0.20% w/w reduced the concentrations of arsenic in soil, root, and aerial parts by 62.53, 43.65, and 37.00% respectively, indicating that application of acrylic copolymer immobilized arsenic in soils.