Study of composition of the soil solution after amelioration of heavy metal contaminated acid soil in model experiment
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Author: Benkova, Maya; Dimova, Lyuba; Simeonova Tsetska
The soil solution is the most important constituent influencing chemical and biological activities in the soil. Apart from the elements in the solid phase of soil little is known about their concentration and speciation in the soil solution. The purpose of this paper is to study the chemical composition of soil solution after amelioration of heavy metal contaminated acid soil in model experiment with a grass mixture. Five kinds of ameliorative mixtures - CaO, peat, coal powder, iron hydroxide and zeolite in 11 treatments have been tested. The soil solution samples were obtained by vacuum application on the RHIZON soil moisture samplers from two soil depth ( 0-15 and 0-30 cm). The concentrations of the following inorganic components: K+, Na+, Ca2+, Mg2+, Cu2+, Zn2+, N-HN4+, N-NO3- and Cl- in the soil solution were analysed. The main soil factories controlled the solution composition: pH and Eh were measured. The results have shown that amendments have effects in changing the solubility and concentration of the elements in soil solution. Application of ameriorants raised solution pH increased Cu and Zn adsorption in soil and resulting in decreased leachability of the soil trace element. Copper and zinc concentrations in the soil solution, where the values of pH are 4.6, are the highest in the control and zeolit treatment.