Laboratory study of successive soil saline leaching and electrochemical lead recovery

摘要

This research is related to a laboratory study on the performance of a successive soil saline leaching and electrochemical lead recovery process for soil decontamination. Erlenmeyer leaching assays showed that the addition of 5.5 mol NaCl/L in 25% (w/w) of soil pulp density maintained at pH 3.0 was found the most effective condition for Pb leaching. Under these conditions, 65%, of Pb was leached from soil. Electrochemical treatment using an iron-monopolar electrode system operated at a current intensity of 3.0 A was able to reduce Ph content in soil leachate from 650 to 0.15 mg/L and this without production of metallic residue. Then, a leaching tank reactor and electrolytic cell coupled in a closed loop showed that the Pb mass balance of extrants/intrants ratio indicated 99.0 +/- 1.6% of Pb was recovered. Likewise. 94.1 % of chloride ions were reused in the leaching tank reactor after electrochemical treatment.