Effects of various ions on the dechlorination kinetics of hexachlorobenzene by nanoscale zero-valent iron

► The degradation kinetics of HCB by NZVI is not affected by HCO3-, Mg2+, and Na+. ► Cl− and SO42- enhance the degradation reaction due to their corrosion promotion. ► NO3- competes with HCB so it inhibits the degradation reaction. ► Cu2+ enhances degradation of HCB resulted from the reduced form of Cu on NZVI. ► Fe2+ inhibits the degradation reaction due to passivation layers formed.