Effect of Iron Dust on Arsenic Accumulation and Nutrient Status of Ipomoea aquatica Grown in Arsenic Contaminated Soil

摘要

A pot experiment was conducted to evaluate the effect of iron dust on arsenic accumulation and nutrient status in Ipomoea aquatica considering the fact that the iron has the ability to react chemically with arsenic and to form different complexes which can reduce the bioavailability of arsenic. The experimental soil was artificially contaminated with sodium metaarsenite (NaAsO₂) at the rate of 50 mg kg^-1. Three treatments (1, 2 and 3%) of Fe-dust were applied to the arsenic contaminated soil along with the control. The plant Ipomoea aquatica under the family of Convolvulaceae was cultivated in the present experiment. Twenty four days after seed sowing, the plant was harvested and analyzed for arsenic and other elements. The arsenic concentration in the edible part of the plant was measured as 7.12±0.91, 8.19±0.81 and 4.16±0.5 mg kg^-1 in 1, 2 and 3% iron-dust applied plants, respectively and the As concentration was 11.06±0.52 mg kg^-1 in control plant. It was found that both the arsenic concentration (mg kg^-1) and arsenic uptake (mg plant^-1) was decreased significantly (p<0.05) with the application of Fe-dust in arsenic contaminated soil. Potassium and zinc concentration was significantly (p<0.05) decreased in the plant part. The results showed that the application of iron dust in the arsenic contaminated soil could be an effective strategy in reducing arsenic uptake in plant.