Determining Effect of Chemical Amendments on Soil Properties in Heavy Metal Contaminated Agricultural Field.

Heavy metal contamination of soil is caused by mining and industrial activities, incineration, agricultural practices, etc., resulting in potential toxic effects for all biota. Chemical stabilization refers to adjust of organic and inorganic materials to modify soil properties such as pH, SOM, CEC, etc., in order to reduce metal mobility, toxicity, bioavailability (adsorption to mineral surfaces, formation of stable complexes with organic ligands, ion exchange, precipitation, etc.). Therefore, main objective of this research was to evaluate application of stabilizing materials on reduction of heavy metals contents and variation of chemical and biological properties in two contaminated soil in laboratory condition. Stabilizing materials, pH control, organic, and mineral, were treated solely with heavy metal contaminated agricultural soil. Variation of heavy metals concentration and properties in soil was monitored during incubation period. During experimental period, arsenic concentration in soil was lowered at the range of about 15-20%, 35-50%, and 50-60% for lime-base materials, organic materials, and rich metal-oxide materials, respectively, comparing to non-treated soil. However, arsenic concentration in soil was increased when calcium superphosphate was applied. In case of lead, concentration was decreased at the range of about 10-100%, 35-80%, and 5-75% for lime-base materials, organic materials, and mineral materials, respectively. Cation exchange capacity in soil was increased 1-23 cmol₍₊₎/kg depending on varied treatment. Result showed that microbial populations in soil was increased compared to control (2*10^-5-4*10^-5 CFU) after mixing with stabilizing materials and organic (6*10^-5-12*10^-5 CFU) > mineral (5*10^-5-11*10^-5 CFU) > pH control (3*10^-5-9*10^-5 CFU).