Removal of Copper Ions from Contaminated Soil by Enhanced Soil Washing

Abstract

This study investigated the feasibility of using different extracting solutions at various concentrations to remove copper from low permeability silty loam soils, which have a high buffering soil, pH of 7.6, where it spiked with copper at concentration of about 1500 mg/kg to represent soil conditions. The most efficient extracting solutions could be used as purging/extracting solutions in other technologies such as soil washing. Several batch tests were conducted to be optimizing the various parameters like stirring speed, mixing time, surfactant-chelating agent concentration, and the liquid/solid ratio (L/S). The following extracting solutions were investigated for the removal of copper from the soils: distilled water, chelating agents (EDTA ethylenediaminetetraacetic acid), and surfactant (SDS, sodium dodecyl sulphate). The metal removal efficiency was found to be dependent on EDTA concentration at case used alone, with the increasing of EDTA concentration, the removal of Cu+2 increased and peaking at approximately 42.4% with increasing of EDTA concentration to 0.1M. The addition of 0.6% SDS retarded copper removal by EDTA, therefor, the removal become approximately 32 %, as compared when EDTA was applied alone.