Evaluate the effects of heavy metal contamination on settlement properties of sandy clay

Document Type : Research Article

Authors

1 رییس مرکز همایش های علمی و کارگاههای تخصصی دانشگاه

2 Student/Technical Faculty/Mohagheghe Ardabili university/Ardabil/Iran

3 Technical faculty/Mohagheghe Ardabili university/Ardabil/Iran

Abstract

Preventing the penetration of leachate of landfill which contains heavy metal into the soil and aquifer layer is one of the most critical issues in the world. High capacity of Clay minerals to exchange cations with other metal onions, made it natural absorbent material. Previous studies show that interaction of clay and metal contaminations leads to variation of surface and micro-structure properties of clay which will results in the changing of geotechnical properties of clay. The aim of this study is to evaluate the settlement properties of sandy-clay kaolinite in the presence of heavy metal. Therefore after preparing samples some laboratory tests such as XRD, settling, absorbent, one dimensional consolidation and liquid limit determination done on the samples in the presence of lead and zinc. The results of XRD and settling show that the presence of lead and zinc change the structure of soil from disperse to flocculation. This phenomenon would intensify with the increase in contamination concentration. The change in structure of clay lead to decrease in void ratio and settlement properties. In addition the result of experiments show that, by increasing the concentration of lead heavy metal from 0 to 25 cmol/kg.soil the initial void ratio of sand-kaolinite with the ratio of 10, 25 and 40 would reduced 0.17, 0.20 and 0.25 respectively. Also this reduction for similar samples in the presence of zinc is 0.13, 0.16 and 0.18 respectively.

Keywords

Main Subjects