Catalytic wet-air oxidation of high strength industrial wastewater

Formaldehyde is a carcinogen compound and one of the most important pollutants contained in wastewaters. Three different treatments were evaluated in a high-pressure batch reactor for the total organic carbon (TOC) degradation of formaldehyde solutions: thermolysis, noncatalytic wet oxidation, and catalytic wet oxidation over a CuO-ZnO/Al 2 O 3 catalyst. The absence of the catalyst leads to a predominant induction period (30 min) without changes in TOC concentrations, while the catalytic treatment leads to significant enhancement in TOC reduction. In the catalytic experiments, an asymptotic behavior was observed with a final TOC reduction of approximately 80%, with the remaining nonoxidizable TOC being due to methanol, a refractory compound contained in the formaldehyde solution that is resistant to oxidation even with increasing temperature and pressure. Formic acid was identified as an intermediary compound, and a new kinetic model was developed, designed as the modified generalized kinetic model, to account for refractory and nonoxidizable compounds. Moreover, leaching of the catalyst in the liquid phase was not significant, and the carbon adsorption capacity was not detected.

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“…Previous works reported the same type of behavior in the oxidation of other pollutants. [18][19][20]…”

Section: Resultsmentioning

confidence: 99%

Catalytic and Noncatalytic Wet Oxidation of Formaldehyde. A Novel Kinetic Model

Silva

Quinta‐Ferreira

Levec

2003

Ind. Eng. Chem. Res.

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“…In order to improve the conditions of such a process, homogenous and heterogeneous catalysts [1][2][3][4][5][6][7][8][9][10][11] were used. Catalytic wet air oxidation (CWAO) is an efficient technique to eliminate organic compounds such as phenols but reaction is performed at high operating pressure (1-10 MPa) and temperature (80-200 • C) makes investment rather costly.…”

Section: Introductionmentioning

confidence: 99%

Investigation of the catalytic wet peroxide oxidation of phenol over different types of Cu/ZSM-5 catalyst

Valkaj

Katović

Zrnčević

2007

Journal of Hazardous Materials

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“…Although the wet air oxydation (WAO) process has demonstrated high effectiveness in the abatement of the organic pollutants [8] [9]. It consists of an oxidation of organic and inorganic compounds in an aqueous solution or suspension by air or oxygen at high temperature and pressure: 423 -573 K and 2 -15 MPa [10]. In order to improve the conditions of such a process, homogenous and heterogeneous catalysts were developed [11]- [13] using strong oxidants such as H 2 O 2 [14] [15].…”

Section: Introductionmentioning

confidence: 99%

Anaerobic Digestion of Olive Oil Mill Wastewater Pre-Treated with Catalytic Wet Peroxide Photo-Oxidation Using Copper Supported Pillared Clay Catalysts

Achma¹,

Ghorbel²,

Dafinov³

et al. 2014

MSCE

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Because phenolic compounds are toxic for methanogenic bacteria many problems concerning the high toxicity and biodegradability of the olive oil mill wastewater (OMW) have been encountered during anaerobic treatments of this effluent. In this work, we try to develop a new catalytic process for the degradation of phenolic compounds, producing less toxic OMW for methanogenic bacteria, facilitating the anaerobic digestion. This process consists of an oxidative reaction using copper supported on alumina pillared clay in presence of a photocatalytic system (H 2 O 2 with UV light). Preliminary results showed that the use of the copper supported catalyst in presence of 0.88% H 2 O 2 (v/v) allows after 2 h colour reduction (25%), significant abatement of total organic carbon (40%), and important removal of polyphenolic compounds (63%) especially those of high molecular mass and subsequently decreases the OMW toxicity from 100% to 70%. This catalytic pre-treatment process of OMW was efficient for anaerobic digestion.

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Catalytic wet-air oxidation of high strength industrial wastewater

Cited by 54 publications

References 23 publications

Catalytic and Noncatalytic Wet Oxidation of Formaldehyde. A Novel Kinetic Model

Catalytic and Noncatalytic Wet Oxidation of Formaldehyde. A Novel Kinetic Model

Investigation of the catalytic wet peroxide oxidation of phenol over different types of Cu/ZSM-5 catalyst

Anaerobic Digestion of Olive Oil Mill Wastewater Pre-Treated with Catalytic Wet Peroxide Photo-Oxidation Using Copper Supported Pillared Clay Catalysts

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