Ex-situ remediation of heavy metals contaminated soils using natural aluminosilicate minerals

Abstract

The effects of zeolite and pyrophyllite on decreasing heavy metals availability in contaminated soil were evaluated in pot experiments. The zeolite and pyrophyllite materials were added to contaminated soil at four rates i.e. 0, 200, 400 and 600 kg ha−1. The available forms of heavy metals from soil samples were extracted using EDTA solution (0.01 mol dm−3 C10H16N2O8 and 1 mol dm−3 (NH4)2CO3, adjusted to pH 8.6) and their concentrations in the obtained extract were determined using atomic absorption spectrophotometry. Zeolite and pyrophyllite incorporation in soil was found to reduce the availability of heavy metals in soil under experimental conditions. The addition of zeolite was more effective in decreasing Cu and Pb availability, while the pyrophyllite showed a better effect on reducing Mn and Cd availability. These results indicated that addition of these clay minerals could be a suitable technique for reducing heavy metals availability in soils. However, the further research is necessary to confirm this hypothesis across different experimentation and soil ecosystems.