Uso de processos oxidativos avançados e ferro elementar na remediação de agua subterranea contendo compostos organoclorados / Use of advanced oxidation process and zero valent ironinremediation of groundwater containing chlorinated compounds

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

The remediation of groundwater containing organochlorine compounds was evaluated in this work using UV (photolysis), Fenton (H2O2/Fe) and photo-Fenton (UV/H2O2/Fe). A reductive system using zero valent iron aiming the reductive dehalogenation of the compounds has also been tested. All the experiments were performed using an upflow reactor operating in a recirculating systems as well as in a single pass mode, using groundwater sample from a monitored well from Rhodia s Cubatão Chemical Plant. The concentration of the compounds reached up to 400 mg L each, while the degradation of the ten most concentrated compounds was monitored. Destructive oxidation yielded reductions higher than 99% for some compounds, especially when using the photo-Fenton system in a 1:10 (COD:H2O2) mass proportion, which produced a synergic effect when compared to the use of ultraviolet radiation (UV) alone. On the other hand, the oxidative systems also presented significant losses through volatilization, which led to the study of the reductive system using zero valent iron. In this system, a glass column packed with granulated iron (100 Mesh) was used, where reductions higher than 99% were achieved for most compounds. The degradation kinetics followed a pseudo first order reaction related to the contaminant and was dependent on the sample residence time in the column. An oxidative test using Fenton reagent after the reductive treatment presented reductions up to three times in the concentration of two compounds that have not achieved the proposed goals: chloroform and tetrachloroethylene. An economical assessment between the currently applied technology (adsorption in activated carbon bed) and the reductive dehalogenation presented significant savings when the cost of the final disposal of the activated carbon was taken into account.

ASSUNTO(S)

fenton chlorinated compounds zero valent iron ferro elementar fenton compostos organoclorados processos oxidativos avançados advanced oxidation process

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