ELECTROKINETIC REMEDIATION OF A CONTAMINATED RIVER SEDIMENT

摘要

Electrokinetic remediation was selected to clean-up river sediment samples containing metallic contamination. A number of experiments were carried out at a lab scale with the purpose of testing the performance of this technique in a 2 dimensional arrangement and establishing the base for future studies. The sediments were obtained from Palmones River and were characterized before use in the experiments. Six metals (Cd, Cu, Fe, Ni, Pb and Zn) were analyzed in the sediments before and after the treatment. The evolution of the electrical potential difference between the electrodes was monitored along the duration of each experiment. The electrical potential drop increased with time, reaching values from 5 to 10 times the initial values. Sometimes, the formation of precipitates in the sediment areas close to the cathode and anode could be observed a few hours after the beginning of an assay. After a few days of operation, pH values decreased below 2 in the anode region and increased above 12 in the cathode region. A near symmetrical distribution of the metals concentration relative to the imaginary line connecting the electrodes was found. Iron presented a different distribution pattern than metals like Zn, Cu and Ni.