Modified Fenton's processes for effective in‐situ chemical oxidation—Laboratory and field evaluation

Abstract

Fenton's reagent in its conventional form, although effective for contaminant treatment, isimpractical from an in-situ field application perspective due to low pH requirements (i.e., pH 3-4)

Remediation of PAH-contaminated sediments by chemical oxidation

“…Hydrogen peroxide can be used alone, but it is considered not kinetically fast enough to degrade most of organic contaminants before its decomposition occurs [19]. In Fenton's reagent, hydrogen peroxide is dosed together with a solution of a transition metal (typically iron) to enhance the radical formation, as the catalyst addition dramatically increases the peroxide oxidative strength [19][20][21][22]29,[31][32][33][34][35][36]. The typical Fenton's reaction is based on the hydrogen peroxide decomposition into hydroxyl radicals in the presence of ferrous iron, according to the reaction:…”

“…chelating agents) and/or by high peroxide concentrations. When high oxidant concentrations are used, many complex reactions are involved in the Fenton's system, and numerous reacting species can be generated in addition to hydroxyl radical, including hydroperoxide radicals (HO 2 • ), superoxide anions (O 2 •− ) and hydroperoxide anions (HO 2 − ) [19,29,30,[34][35][36]:…”

“…Therefore, vigorous oxidation condition can allow to increase the remediation efficiency, by attacking even the most refractory compounds. On the other hand, too high peroxide concentrations must be avoided, as they can enhance the oxidant self-consumption [33,34], leading to poorer oxidant efficiency.…”

Enhanced biosorption of metal ions from wastewater by Fenton modified Hydrilla verticillata dried biomass

“…In addition to this, Fenton process has numerous significant advantages; for instance, reagents are inexpensive, short reaction time among all advanced oxidation processes (Pouran et al 2013), iron is highly abundant, hydrogen peroxide is easy to handle and environmentally benign (Munter 2001;Venny et al 2012), high efficiency of mineralization facilitates the conversion of organic pollutants into non-toxic carbon dioxide (Nidheesh et al 2013), and the overall procedure is easy to execute and control (Argun and Dursun 2008;Miretzky and Munoz 2011). Hydrogen peroxide used in the Fenton process would cause no environmental or ecological threat because diluted and stabilized hydrogen peroxide (5-20 %) was applied, which not only promotes a safer working environment during exothermic in situ application of Fenton reaction, but also results in enhanced treatment efficiency throughout the in situ remediation compared to concentrated H 2 O 2 (30-35 % commercial grade), as already reported elsewhere (Kakarla et al 2002;Venny et al 2012).…”

Lab-scale feasibility tests for sediment treatment using different physico-chemical techniques

“…The oxidants most commonly used for environmental applications include ozone, hydrogen peroxide, Fenton's reagent and modified Fenton's reagents (i.e., iron-catalyzed hydrogen peroxide), permanganate, and persulfate. The effectiveness of the treatments relies on many factors including the nature and the level of contamination and the solid matrix characteristics such as the organic matter content and the particle size distribution (Kakarla et al 2002;Watts et al 2002;Flotron et al 2005;Bissey et al 2007). Electrokinetics uses a low-level electric current or an electric voltage across electrodes placed in the porous medium (Acar et al 1995).…”