Role of bentonite, illite, hematite, zeolite, and calcite in decreasing of heavy metals adsorption by polluted wastewater in Tabriz city

Heavy metals fixation in-situ by using inorganic amendments, is a method for remediation of polluted soils. The goal of this research is to determine 5 kinds of amendments feeiciency for heavy metals fixation of waste-water-irrigated soils in around of Tabriz city and to suggeste the best amendment/amendments. solutions containing CD, Pb< Cu, Ni, and Zn were added to 0.5 gram of 5 amendments including calcite, hematite, zeolite, illite, and bentonite; and 10 soil samples from around of Tabriz city. After shaking, these 5 element concentrations were determined in filtered solution by using atomic absorption instrument. Retention capacity percentages of these elements were ca;culated and by using dankan method, the best amendments were determined. There were sharp differnences of heavy metals retention between amendments. Calcite had the highest retention of Cd, ni, and Zn; hematite the highest one of Cu and Pb; and the least one was for ilite. Calciye, zeolite, bentonite, and hematite had significant (in 5 % level) higher retention capacities of Cd, Ni, and Zn in compared to 10 the soil samples. The highest retention capacities was done by calcite and hematite (without significant differences) for Pb. Calcite hematite, and zeolite had the highest retention of Cu. However, the highest retention was done by illite with significant difference with other 2 amendments. The retention capacities of calcite and hematite amendments for the 5 elements were higher than all 10 the soil samples in 5 % level and can cause low uptake and accumulation of these elements in agricultural crops of polluted soils of around of Tabriz city.