Speciation and stabilization of some heavy metals in the sediments from drains, Egypt

Abstract

Speciation has been used to indicate the chemical forms of metals and to measure their distribution in the sediment. Therefore, sequential extraction techniques were used to distinguish between different physicochemical states of metals and give detailed information on mobilization and their transportation. This work aimed to determine the total metals concentrations and their fractionation pattern (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in the sediment samples. Also, solidification/ stabilization processes were used to reduce the mobility of metal contaminants by the addition of an agent that solidifies and then immobilizes the metals. The data showed that metal fractionation is relatively stable under normal conditions except for Cd, Zn, and Mn, which were distributed mainly in the mobile fraction for all samples of Talkha drain, Egypt, while, in Rahway drain, Egypt, all heavy metals were found in the stable form bound to organic sulfide and residual fractions except for, Mn and Zn, which distributed mainly in the unstable form. The data showed that 50% of cement kiln dust was sufficient to reduce the mobility of metals by increasing their percentages in the stable forms.

Keywords:

• Sediment
• Sequential extraction procedure
• Stabilization
• Cement kiln dust