Use of Various Zero Valent Irons for Degradation of Chlorinated Ethenes and Ethanes

Amongst all of the reducing agents that can be used in environmental remediation, zero valent iron (ZVI) is one of the most common due to its environmental acceptance, high reaction rate, good availability, and long-term stability. Moreover, ZVI mobility, stability and reactivity can be enhanced by the application of a DC electric current, ie electrokinetics (EK). In the study, six various slurries containing different ZVI were tested for their efficacy for chlorinated ethenes and ethanes degradation. Chlorinated compound concentrations, pH, oxidation-reduction potential (ORP) and conductivity were determined during the long-term kinetic test. Kinetic rate constants calculated for the degradation of three chlorinated ethenes (PCE, TCE and cis-DCE) concluded that EK brings substantial contribution to chlorinated compounds degradation. Nano-scale zero valent iron STAR had the highest reaction rates compare to the other ZVI tested. The performed study could serve as a preliminary assessment of various available ZVI before in-situ application.