Degradation of 2-chloroaniline, 3-chloronitrobenzene and 1,2,4-trichlorobenzene in river sediments

The disappearance kinetics of three chlorinated aromatic compounds (2-Chloroaniline, 3-Chloronitrobenzene and 1,2,4-Trichlorobenzene) in a sediment-water system are described. Analyte concentrations in three definite compartments (water, interstitial water and sediment core) are indicated. Concentration versus time data for the reaction in the water phase complies with first-order kinetics, while for the analytes in the sediment phase disappearance kinetics do not follow first-order kinetics. A bi-exponential mathematical expression that takes into account the two different initial concentrations and reaction rates in both the interstitial water and sediment core is used to fit data for analyte concentration in the sediment phase. An overall expression is then used to model the kinetics in the entire sediment-water system. The highest degradation rate is found in the interstitial water. A description is also given of the effects of the temperature on the disappearance kinetics observed. Two reaction products are also identified by GC-MS.