Strategy of Phytoremediation for Sustainable Use of Arsenic-Rich Farmland

Abstract

Arsenic-rich groundwater causes arsenic accumulation in arable soils for irrigation. For such arsenic-contaminated farmland, phytoremediation is a feasible method in terms of cost and maintenance of soil. We studied arsenic-rich farmland planted with maize, Rotala rotundifolia, and the arsenic super-accumulating plant Pteris vittata and explored the arsenic absorption capacity of these plants to assess the effect of phytoremediation on arsenic-contaminated farmland. The arsenic removal by Pteris vittata was about 200 mg/m2 y. It would take about 90 years to reduce the soil arsenic below the regulatory standard of 60 mg/kg using Pteris vittata. Planting maize removed about 25.5 mg/m2 y of arsenic, and the arsenic concentration of the maize kernels was less than 0.2 mg/kg on a dry basis. It was below the standards of the animal food and human consumption limit. Pteris vittata needs to be planted first to rapidly reduce the bioavailable arsenic concentration in the soil. Subsequent planting of maize for remediating the soil while producing corn enables the sustainable production and utilization of farmland.

Keywords

• phytoremediation
• arsenic
• farmland
• phytoattenuation
• maize