Reactivity of Nitrate with Zero-Valent Iron

Elevated nitrate concentrations in groundwater and surface water supplies can negatively impact the quality of environment human health. Recent studies have examined use zero-valent iron technology to treat nitrate-contaminated groundwater. Mechanistic aspects reduction by are unresolved. This project investigated kinetics mechanism under anoxic conditions oxic conditions. Stirred-batch reactions were studied over environmentally relevant ranges reactant concentration, pH, temperature. A complex rate expression was derived with a 1.8 order dependence on nitrate, 1.4 iron, fractional (0.8) proton An apparent activation energy 35 kJ mol−1 observed indicating that diffusion controlled our Furthermore, calculated entropy value −162 J mol−1K−1 indicates this reaction occurred an associative mechanism. Under conditions, there lag period where oxygen preferentially utilized, leading slower when compared These data be used predicting disappearance wastewater treated iron.