The Fenton's regent was applied to decolor and degrade2,4-dinitrophenol (DNP). Different concentrations of ferrous ion(Fe~2+) and hydrogen peroxide (H_2O_2) were dosed to investigatetheir influences on the removal of DNP. The ADMI color value wasadopted as an index to indicate the decoloring performance of thereaction. Low molecular weight of organic acids was monitored, andthe role of dissolved oxygen during the DNP degradation wasdiscussed. Results show that due to productions of coloredintermediates and the oxalic acid, DNP was quickly removed, followedby the ADMI color value and DOC, respectively. Both initial removalrates of DNP and ADMI color value increased linearly at low dosagesof Fe~2+ and H_2O_2. A high dosage of F~2+ (>1mM) led to aninsignificant response of the initial removal rate of DNP, whereasthe initial removal rate of ADMI color value was not affected andkept increasing constantly. Because of the non-selective feature ofthe hydroxyl radical, leveling off in the initial removal rates ofADMI color value was observed when dosing with a high concentrationof H_2O_2. The variation in dissolved oxygen associated with a changein color led to a proposed pathway to depict the oxidation of DNP ina Fenton's reaction.
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