Pyrene removal from contaminated soils by modified Fenton oxidation using iron nano particles

Abstract

BackgroundThe problems related to conventional Fenton oxidation, including low pH required and production of considerable amounts of sludge have led researchers to investigate chelating agents which might improve the operating range of pH and the use of nano iron particle to reduce the excess sludge. The pyrene removal from contaminated soils by modified Fenton oxidation at neutral pH was defined as the main objective of the current study.MethodsVarying concentrations of H2O2 (0-500 mM) and iron nano oxide (0-60 mM), reaction times of 0.5-24 hours and variety of chelating agents including sodium pyrophosphate, sodium citrate, ethylene diamine tetraacetic, fulvic and humic acid were all investigated at pyrene concentration levels of 100 – 500 mg/kg.ResultsBy applying the following conditions (H2O2 concentration of 300 mM, iron nano oxide of 30 mM, sodium pyrophosphate as chelating agent, pH 3 and reaction time of 6 hours) the pyrene removal efficiency at an initial concentration of 100 mg/kg was found to be 99%. As a result, the pyrene concentration was reduced from 100 to 93 mg/kg once the above optimum conditions are met.ConclusionsIn this research, the modified Fenton oxidation using iron nano oxide at optimum conditions is introduced as an efficient alternative method in lab scale for chemical remediation or pre-treatment of soils contaminated by pyrene at neutral pH.

Impact of a Modified Fenton Process on the Degradation of a Component Leached from Microplastics in Bottom Sediments

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Remediação De Solos Contaminados Com Fenantreno Por Oxidação Química in Situ Utilizando Persulfato De Sódio Ativado Com Argila Chocolate Modificada

“…A ativação convencional deste oxidante, a partir da ativação por Fe 2+ , para geração de radicais sulfato (SO4 -•), ocorre em pH baixo. O meio ácido, portanto, pode alterar as características naturais do meio e afetar negativamente os sistemas existentes (Jorfi, 2013). Assim, a necessidade de trabalhar com um pH baixo pode ser considerada uma das desvantagens do método convencional (Silva, 2014).…”

Rapid degradation of contaminated soil with 2‐methylpropane‐2‐thiol by H2O2/KMnO4/NaClO system: process modeling and optimization

“…2a). When initial concentration of hydrogen peroxide in presence of Fe 2+ increases, further OH • radicals that are very powerful and effective oxidizing agents are accessible to attack the 2-methylpropane-2-thiol molecules according to decomposition reaction (Eqn (11)) [40,[61][62][63] :…”