STOCHIOMETRY OF FENTONS-REAGENT IN THE OXIDATION OF CHLORINATED ALIPHATIC ORGANIC POLLUTANTS

The stoichiometry of Fenton's reagent in the oxidation of dichloroethy lene (DCE), trichloroethylene (TCE), tehrachloroethylene (tetra-CE), a nd dichloroethane (DCEA) was investigated. The theoretical optimal rat io between H2O2 and Fe2+ is found to be 11. However, the experimentall y determined optimal ratio between H2O2 and Fe2+ ranged from 5 to 11 a t optimal pH of 3.5. The amount of H2O2, required for a specific perce ntage removal of the organic compounds depends upon the initial organi c concentration to be oxidized. The accumulation of chloride ion relea sed also depends upon the initial organic substance concentrations. Th e typical percentage removal of organic compounds and percentage relea se of chloride ion were reported at 100%, 70%, 50%, 40%, 30%, 20%, 10% , and 1%. The amount of H2O2 required to achieve a certain percentage removal follows the order of TCE < Tetra-CE < DCE << DCEA. However, th e amount of chloride ion detected at a constant concentration of H2O2, follows the order of DCEA << DCE < TCE < Teha-CE.