APPLICATION OF ZEOLITE AND BENTONITE FOR STABILIZING LEAD IN A CONTAMINATED SOIL

• Main Authors: Agnieszka Andrzejewska, Jean Diatta, Tomasz Spiżewski, Włodzimierz Krzesiński, Anna Smurzyńska
• Format: Article
• Language: Polish
• Published: Polish Society of Ecological Engineering (PTIE) 2017-08-01
• Series: Inżynieria Ekologiczna
• Subjects: contamination; stabilization; lead; zeolite; bentonite
• Online Access: http://www.journalssystem.com/ie/ZASTOSOWANIE-ZEOLITU-I-BENTONITU-DO-STABILIZACJI-OLOWIU-W-GLEBIE-ZANIECZYSZCZONEJ,74950,0,2.html

Lead is a toxic element, which often is incorporated into the trophic chain. It is poorly susceptible to migration into the soil profile, and its presence in the upper layers of the soil is caused by anthropogenic factors. Zeolites are crystalline hydrated aluminosilicates containing in theis structure a system of chambers and channels associated with each other. The same applies to the bentonite which contain not less than 75% montmorillonite. Both clay mineral / sorbents are characterised by high sorptive properties, with a prevalence in the case of the bentonite. The incorporation of these sorbents into the soil can effectively immobilize contaminants, especially heavy metals. The study evaluated the properties of zeolite and bentonite for stabilizing lead (Pb) in a contaminated soil. Sorbents were applied at different rates 0, 0.25, 0.5, 1.0, 2.0, and 3.0% to the contaminated soil and incubated for four months. Soil reaction (pH) was measured as well as the electrical conductivity (EC). The total content of Pb was determined in the soil samples as did the reactive forms (extracted by 0.11 mol CH₃HCOOH dm^-3). The evaluation of the efficiency of the stabilization of Pb was performed on the basis of the fractions of the reactive lead. It was found, that the addition of both zeolite and bentonite resulted in a decrease in the concentrations of the active forms of lead in soils. Thus, the two sorbents exerted a good stability and can be used for efficiently immobilizing lead in soil contaminated anthropogenically.