Retention of clay-solidified grouting curtain to Cd²⁺, Pb²⁺ and Hg²⁺ in landfill of municipal solid waste

Abstract

The effects of components and their ratio of groups on anti-seepage capability of clay-solidified grouting curtain and its permeability of heavy metal cations were investigated by permeating experiments, using reactive solute transport model to study the permeation of heavy metals (Cd²⁺, Pb²⁺ and Hg²⁺). The study of permeating for different mixture ratios of cement and clay indicates that hydraulic conductivity of clay-solidified groupting curtain with different ratios of solid to liquid or with the same ratio of solid to liquid but with different ratios of cement to clay is changed. The laboratory simulation test results also show that precipitates produced in heavy metal cation migration process in curtain block up water flowing passage which makes the hydraulic conductivity of the solution-permeated curtain decrease with the leakage time. The permeation velocities for different heavy metal cations vary with ionic concentration, exchange capacity and ion radius etc. The test results indicate that the permeation rapidity order of heavy metals cations in clay-solidified grouting curtain is Hg²⁺ > Pb²⁺ in the same experimental circumstance. In addition, permeability for different mixture ratios and antisepsis capabilities of clay-solidified grouting curtain were studied in tests.

Keywords

clay-solidified grouting / solid-waste landfill / leachate / heavy metal cation / hydraulic conductivity / anti-seepage curtain

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