Stabilization of Heavy Metals in Contaminated Soil around Zinc Mining Area by Sediment from Water Supply Plant for Cultivation of Rice

Abstract

A study on effectiveness of sediment from water supply plant for fixing heavy metals in contaminated soil and leachate reduction was conducted. The top soil samples (0-15 cm) were collected from zinc mining site at Mae Tao Sub-district, Mae Sot district, Tak province. Analysis results of heavy metals which contaminated in soil by US-EPA 3051 method and atomic absorption spectroscopy revealed that concentration of the soil concentration of Cd Pb Zn and Mn were 37.60, 135.51, 770.00 and 500.80 mg kg-1 respectively. The heavy metals removal efficacy of sediment was investigated by batch experiment. It was found that, sediment 2 g can remove Cd and Zn for 10 to 40 mg/l over than 95% and Mn 59.72%. The ratios between sediment and contaminated soil at 1:1 gave the highest removal efficacy. For pot treatment, which were designed in completely randomized design (CRD) with 7 treatments and 3 replications. The results shown that the pot with rations of soil 5 kg : sediment 5 kg : fertilizer 20 kg and pig manure 70 kg gave the highest rice yield (889.00 kg/ha) and the weight of rice grain was 38.60 g per 1000 seed. The rice grain was uncontaminated by heavy metals. Furthermore, the heavy metals in leachate from all pot treatments with sediment were lower than standard value.