Well-known, yet undefined, changes in the conditions and activity of palladized zerovalent iron (Fe/Pd) over an extended period of time hindered a careful study of dechlorination kinetics in long-term experiments. A short-term experimental method was, therefore, developed to study the effects of temperature and solvent on the dechlorination of monochlorobipheryls (MCBs), 2-chlorobiphenyl (2-CIBP), in particular by Fe/Pd. The experiments started with specified initial conditions and lasted only for 10 min. The average value ((k) under bar) of the first-order rate constant for the dechlorination of 2-CIBP was 0.13 +/-0.03 L m(-2) h(-1), not significantly different from the average values for 3-chlorobiphenyl and 4-chlorobiphenyl. The apparent activation energy was 20 +/- 4 U mol(-1) and 17 +/- 7 U mol(-1), in a temperature range between 4 degrees C and 60 degrees C, for the dechlorination of 2-CIBP using two batches of Fe/Pd catalyst. The (k) under bar values decreased significantly in mixtures with a methanol concentration higher than 10%. The values of the rate constant were slightly influenced by the initial concentrations in the experiments at a low temperature and in a solution with a high methanol concentration. The concentration dependence was described with a Langmuir equation, based on the Langmuir-Hinshelwood mechanism that includes an adsorption step of a single species preceding a rate-determining catalytic reaction. (c) 2007 Elsevier B.V. All rights reserved.