Determination of adsorption efficiency based on cation exchange capacity related to red earth, bone meal and pulverised fly ash as ameliorants to lead contaminated soils
Efficient treatment strategies to reduce the toxicity of metal contaminated soil using cost effective techniques such as naturally available ameliorants and industrial waste have emerged. Three easily available amendments were determined: Bone meal, red earth/mud and pulverised fly ash (PFA). The application of ameliorants offered a possible alternative in situ remediation of contaminated sites without disruption to the ecosystem profile. In comparison to other ameliorants Red earth/mud was found to be efficient in intercepting lead leaching from soil amended with different lead compounds based on CEC (Cmol/g). This was associated with the heterogeneous adsorbency principle in red mud which is associated with its ability to bind metal ions (M2+) onto one or two types of surface sites at pH< 6.0. However areas that need to be studied and assessed (for public health concerns) critically for wide spread application of all the ameliorants include off-site effects of the ameliorants.