Using Asclite to Reduce Arsenic Concentration in Vegetables Grown on Arsenic Contaminated Soil

Three pot experiments were conducted to assess the capacity of asclite in reducing arsenic (As) contents in vegetable plants from arsenic contaminated soil. Asclite is an artificially made granular amorphous iron (Fe)-hydroxide material having high ability in adsorbing As(III) as well as As(V). In the first experiment, Japanese mustard spinach (JMS) (Brassica rapa var. perviridis) was grown in a 242 mg As kg-1 soil with 10 and 20% of asclite application. The second and third experiments were conducted in Japan and Bangladesh, respectively, with JMS and Bangladesh spinach (BS) (Spinacia oleracea) grown in a 50 mg As kg-1 soil where 1 and 2% asclite were applied. Application of asclite to arsenic contaminated soil significantly reduced the arsenic concentration in the edible part of the plants as compared to the control plants. The arsenic concentration in JMS reduced by 43 and 60% at 10 and 20% asclite application when grown in a 242 mg As kg-1 soil. The arsenic concentration was reduced by 29 and 37% in JMS, whereas it was 52 and 74% in BS, at 1 and 2% asclite application, respectively, when grown in a 50 mg As kg-1 soil. There was no significant change in the growth and the nutrient elements concentration in the plants. Our findings suggested that asclite could be used to reduce arsenic concentration in vegetables grown on arsenic contaminated soil. Considering the soil type, soil pH, soil arsenic concentration and plant species, further study is required to examine the desirable conditions for reducing the arsenic concentration in vegetable plants with asclite application.