Effects of nutrients on arsenic accumulation by arsenic hyperaccumulator Pteris vittata L.

Abstract

This research investigated the effects of various nutrients on arsenic (As) removal by arsenic hyperaccumulator Pteris vittata L. in a Hoagland nutrient solution (HNS). The treatments included different concentrations of Ca and K in 20% strength of HNS, different strengths of HNS (10, 20 and 30%), different strengths of HNS (10 and 20%) with and without CaCO 3, and different concentrations of Ca, K, NO 3, NH 4, and P in 20% strength of HNS. The plants were grown in nutrient solution containing 1 mg As L −1 for 4 weeks except the Ca/K experiment where the plants were grown in nutrient solution containing 10 or 50 mg As L −1 for 1 week. Adding up to 4 mM Ca or 3 mM K to 20% strength HNS significantly ( P < 0.05) increased plant arsenic accumulation when the solution contained 10 mg As L −1. Plant arsenic removal was reduced with increasing Ca and K concentrations at 50 mg As L −1. Lower strength of HNS (10%) resulted in the greatest plant arsenic removal (79%) due to lower competition of P with As for plant uptake. Addition of CaCO 3 to 20% strength of HNS significantly increased arsenic removal by P. vittata. Among the nutrients tested, NO 3 and CaCO 3 were beneficial to plant arsenic removal while NH 4, P and Cl had adverse effects. This experiment demonstrated that it is possible to optimize plant arsenic removal by adjusting nutrients in the growth medium.