Fenton’s treatment

Hydroxyl radicals are produced from hydrogen peroxide via different pathways and to different efficiencies depending on the nature of the catalyst (AOP system) involved. Figure 5.1 demonstrates hydroxyl radical production efficiencies for the three most commonly applied technologies Fenton s treatment, UV/H202 and 03/H202. 

Figure 5.1 Hydroxyl radical production via Fenton s treatment, UV/hydrogen peroxide and ozone I hydrogen peroxide.

The technology behind Fenton s treatment dates back over a hundred years to 1894 when M.J.H. Fenton reported that ferrous ion promoted the oxidation of tartaric acid with aqueous hydrogen peroxide." Ferrous-catalysed hydrogen peroxide at acidic pH has since come to be known as Fenton s reagent and is widely used in both oxidative treatment of industrial effluents and in the manufacture of several types of polymers and polyelectrolytes. Subsequently,... 

A typical Fenton s treatment installation requires facilities for storing and dosing chemicals (hydrogen peroxide, ferrous catalyst, acid and alkali for pH adjustment), a reaction tank, a settlement tank or centrifugal pump for solids removal and a UV-VIS lamp if photo-Fenton s is to be employed. The use of Fenton s and photo-Fenton s systems are likely to grow in use over the next decade as environmental legislation becomes more widespread, and as the systems become more efficient. 

Protonated nitrogen heterocycles can be carbalkoxylated" by treatment with esters of a-keto acids and Fenton s reagent. Pyridine is carbalkoxylated at C-2 and C-4, for example. The attack is by "COOR radicals generated from the esters ... 

The preparation was performed on a commercial microcrystalline beta zeolite. The zeolite was treated with the Fenton s reagent and less than 0.3 wt% of carbon remained after the treatment. The porosity was fully developed as revealed by the pore-size distribution. Elemental analysis combined with TPR did confirm the high degree of Fe-exchange (98%) on the Bronsted sites. 

From the 323 MTBE projects in U.S. EPA s MTBE Treatment Profiles dataset, 21 projects were identified where MTBE was treated using ISCO. No ISCO projects reported treating other oxygenates. Four of the projects used ozone and 17 used hydrogen peroxide, either alone or with Fenton s chemistry. 

El-Gohary FA, Badawy MI, El-Khateeb MA, El-Kalliny AS (2009) Integrated treatment of olive mill wastewater (OMW) by the combination of Fenton s reaction and anaerobic treatment. J Hazard Mat 162 1536-1541... 

Lodha B, Chuaudhari S (2007) Optimization of Fenton-biological treatment scheme for the treatment of aqueous dye solutions. J Hazard Mater 148 459-466... 

Tantak NP, Chaudhari S (2006) Degradation of azo dyes by sequential Fenton s oxidation and aerobic biological treatment. J Hazard Mater 136 698-705... 

To the best of our knowledge, the only work until now published that combines a chemical process with a biological process using yeasts was presented by [35]. This study describes the employment of an AOP - Fenton s reagent - as a pretreatment for further aerobic treatment with the yeast C. oleophila in the decolorization of the azo dye C.I. Reactive Black 5 (RB5). 

Fenton s reagent, 14 38-39, 65 Fenton s reagent effluent treatment, 9 435 Fenugreek, 23 167 Fenuron, 13 324... 

Contaminated soil from a manufactured coal gas plant that had been exposed to crude oil was spiked with acenaphthene (400 mg/kg soil) to which Fenton s reagent (5 mL 2.8 M hydrogen peroxide 5 mL 0.1 M ferrous sulfate) was added. The treated and nontreated soil samples were incubated at 20 °C for 56 d. Fenton s reagent did not promote the mineralization of acenaphthene by indigenous microorganisms to any appreciable extent. The mineralization of acenaphthene was enhanced only 1.2-fold when compared with the nontreated control sample. The amounts of acenaphthene recovered as carbon dioxide after treatment with and without Fenton s reagent were 20 and 17%, respectively (Martens and Frankenberger, 1995). 

Bigda, RJ. Consider Fenton s chemistry for wastewater treatment. 

In many cases, a combination of physical, chemical, physico-chemical, and biotechnological treatments may be more efficient than one type of treatment (Table 3). Efficient pretreatment schemes, used prior to biotechnological treatment, include homogenization of sohd wastes in water, chemical oxidation of hydrocarbons by H2O2, ozone, or Fenton s reagent, photochemical oxidation, and preliminary washing of wastes by surfactants. 

Oxidative processes can be based on ozonation, UV treatment, hydrogen peroxide, and Fenton s reagent for the destruction of the chromopore [96-107]. 

Acridine is readily oxidized to acridone by sodium dichromate and acetic acid. Pyridin-2-one and nicotinic acid have been found to undergo oxidation to oxalic add on treatment with Fenton s reagent (69CHE563). 

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