Removal of Chloro Derivatives of Ethene from Ground Water with Granulated-Iron Reaction Barriers

Page: 176

M. Jiříčeka,b, O. Šráčeka,c and V. Jandab

a OPV Ltd., Prague, b Department of Water Technology and Environmental Engineering, Institute of Chemical Technology, Prague, c Institute of Geological Sciences, Faculty of Science, Masaryk University, Brno


Reduction of chlorinated ethenes with iron metal was studied in pilot-plant tests. The test showed a sufficient ability of the iron material to reduce a mixture of tetrachloroethene and trichloroethene. The reactions were well approximated by the first-order kinetics. The rate constants per surface area were 0.22 ± 0.11 and 0.44 ± 0.09 mL m−2 L−1, respectively. Significant changes of Ca, total Fe, HCO3, and NO3 concentrations were found in the reaction zone. Speciation calculations indicated aragonite and siderite as possible precipitating minerals. The change in HCO3 concentration in the reaction zone was gradual and could be approximated by zeroth-order reaction kinetics with the rate constant value 0.096 mol L−1 h−1. The surface precipitate may influence the operating life of a permeable reactive barrier as a consequence of permeability decrease and coating of iron.


Full text (PDF)