A combination of new and previously reported data on the kinetics of d
ehalogenation by zero-valent iron (Fe-0) has been subjected to an anal
ysis of factors effecting contaminant degradation rates. First-order r
ate constants (k(obs)) from both batch and column studies vary widely
and without meaningful correlation. However, normalization of these da
ta to iron surface area concentration yields a specific rate constant
(k(SA))that varies by only 1 order of magnitude for individual halocar
bons. Correlation analysis using k(SA) reveals that dechlorination is
generally more rapid at saturated carbon centers than unsaturated carb
ons and that high degrees of halogenation favor rapid reduction. Howev
er, new data and additional analysis will be necessary to obtain relia
ble quantitative structure-activity relationships. Further generalizat
ion of our kinetic model has been obtained by accounting for the conce
ntration and saturation of reactive surface sites, but k(SA) is still
the most appropriate starting point for design calculations. Represent
ative values of k(SA) have been provided for the common chlorinated so
lvents.