Kinetics of lindane dechlorination by zero valent iron microparticles: Effect of different salts and stability study.

Abstract

This report is focused on the dechlorination of lindane, a recalcitrant and refractory pollutant, by zerovalent iron microparticles (ZVIM) in batch and continuous mode. Experimental variables such as initial lindane concentration, ZVIM dosage, and temperature were studied. Batch experiments indicate that the lindane dechlorination is enhanced with the increase of ZVIM dosage and reaction temperature, and is maintained with increasing initial pollutant concentration. Kinetic analyses elucidated that lindane degradation followed a first order reaction for both pollutant and ZVIM concentration. The kinetic model can also accurately predict the results in continuous mode (more realistic conditions), where the high stability of ZVIM has been thoroughly demonstrated. Further studies indicated that coexistence of common ions can (i) not affect (SO42–, Na+, Ca2+, Mg+) or (ii) promote (HCO3–, Cl–) the lindane dechlorination process. The results implied that the use of ZVIM is a potential approach for in situ remediation of soil and groundwater lindane contamination.