Arsenic Uptake from Arsenic-Contaminated Water Using Hyperaccumulator Pteris vittata L.: Effect of Chloride, Bicarbonate, and Arsenic Species

Abstract

High As groundwater normally contained high concentrations of Cl - and HCO 3 - . This study examined the effects of Cl-, HCO 3 -, and As species on As uptake by hyperaccumulator Pteris vittata. Plants were exposed hydroponically to 5.0 mg/L As(III) or As(V) in the presence of 0, 0.5, 1, 2, 5, 10, and 20 mM of Cl- or HCO 3 - for 10 days. Addition of high Cl- concentrations (10 mM) slightly inhibited P. vittata growth (biomass), while generally had no significant effect on plant As uptake. High solution pH resulted in reduced plant growth and As uptake, which attributed to the inhibitory effects in HCO 3 - treatments with the high pH of the high HCO 3 - concentration. It was speculated that addition of HCO 3 - (20 mM) would have no significant effect on plant growth and As uptake. The inhibitory effect of HCO 3 - on As translocation was less apparent in the As(III) solutions than the As(V) solutions. For the high As groundwater with As(III) as the predominant species, high pH, instead of high concentrations HCO 3 - and Cl-, was expected to inhibit As uptake. The results suggested that optimum plant growth and maximum As hyperaccumulation could be achieved by adjusting solution pH in the growth media (around 7.2). 2012 Springer Science+Business Media B.V.