Dechlorination of short chain chlorinated paraffins by nanoscale zero-valent iron

► This is the first report of dechlorination of SCCPs by NZVI. ► A proper amount of humic acid can promote dechlorination. ► Chain length and chlorination degree have a polynominal effect on dechlorination reaction. In this study, nanoscale zero-valent iron (NZVI) particles were synthesized and used for the reductive dehalogenation of short chain chlorinated paraffins (SCCPs) in the laboratory. The results show that the dechlorination rate of chlorinated n-decane (CP10) by NZVI increased with decreased solution pH. Increasing the loading of NZVI enhanced the dechlorination rate of CP10. With an increase in temperature, the degradation rate increased. The reduction of CP10 by NZVI was accelerated with increasing the concentration of humic acid up to 15mg/L but then was inhibited. The dechlorination of CP10 within the initial 18h followed pseudo-first order rate model. The formation of intermediate products indicates a stepwise dechlorination pathway of SCCPs by NZVI. The carbon chain length and chlorination degree of SCCPs have a polynominal impact on dechlorination reactions.