Destruction of Trichloroethylene with Zerovalent Iron/ Persulfate
Anita Padmanabhan and John Bergendahl. Department of Civil Engineering, Worcester Polytechnic Institute, Kaven Hall, 100 Institute Road, Worcester, MA 01609
Research was undertaken to find the potential for zero valent iron (Fe0)/persulfate treatment of trichloroethylene (TCE) contaminated water. The Fe0 activated the persulfate to produce sulfate free radicals, a powerful oxidant used for destroying organic contaminants in water. Batch experiments showed that Fe0/persulfate removed TCE more effectively than persulfate alone, and was more effective than ferrous iron activated persulfate. The results indicated that destruction occurred over a wide range of pH values. The production and destruction of intermediates cis 1,2 dichloroethylene and vinyl chloride was observed. The effect of persulfate dose on this reaction was investigated. Results demonstrated that a molar ratio of 10/1/1 (persulfate/Fe0/TCE) yielded over 95 percent TCE destruction. Increasing the persulfate dose resulted in greater TCE destruction as well as destruction of the intermediates. Kinetic experiments at a molar ratio of 10/1/1 (persulfate/Fe0/TCE) showed that approximately 90 percent of the TCE was destroyed in less than 15 minutes.