Anodic oxidation of phenol for waste water treatment
01 Aug 1991-Journal of Applied Electrochemistry (Kluwer Academic Publishers)-Vol. 21, Iss: 8, pp 703-708
TL;DR: In this article, the electrochemical oxidation of phenol for waste water treatment was studied at a platinum anode, and the reaction occurs by two parallel pathways; chemical oxidation with electrogenerated hydroxyl radicals and direct combustion of adsorbed phenol or/and its aromatic intermediates to CO2.
Abstract: The electrochemical oxidation of phenol for waste water treatment was studied at a platinum anode. Analysis of reaction intermediates and a carbon balance has shown that the reaction occurs by two parallel pathways; chemical oxidation with electrogenerated hydroxyl radicals and direct combustion of adsorbed phenol or/and its aromatic intermediates to CO2.
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1,837 citations
TL;DR: The present tutorial review summarizes the results of an extensive selection of papers dealing with electrochemical oxidation, which is proposed as an alternative for treating polluted wastes, to discuss the possibility of removing selected contaminants from water using different anodes.
Abstract: In recent years, there has been increasing interest in finding innovative solutions for the efficient removal of contaminants from water, soil and air. The present tutorial review summarizes the results of an extensive selection of papers dealing with electrochemical oxidation, which is proposed as an alternative for treating polluted wastes. Both the direct and indirect approaches are considered, and the role of electrode materials is discussed together with that of other experimental parameters. Apart from discussing the possibility of removing selected contaminants from water using different anodes, efficiency rates for pollutant removal have been collected, the dependence of these rates on operational conditions advantages and disadvantages determining the further full-scale commercial application.
1,428 citations
TL;DR: In this paper, the authors present a general review of advanced oxidation processes developed to decolorize and/or degrade organic pollutants and highlight the application of nano-zero valent iron in treating refractory compounds.
Abstract: The increase in the disposal of refractory organics demands for newer technologies for the complete mineralization of these wastewaters. Advanced oxidation processes (AOPs) constitute a promising technology for the treatment of such wastewaters and this study presents a general review on such processes developed to decolorize and/or degrade organic pollutants. Fundamentals and main applications of typical methods such as Fenton, electro-Fenton, photo-Fenton, sono-Fenton, sono-photo-Fenton, sono-electro-Fenton and photo-electro-Fenton are discussed. This review also highlights the application of nano-zero valent iron in treating refractory compounds.
1,256 citations
TL;DR: A critical review of recent research identifies future opportunities and research needed to overcome major challenges that currently limit the application of electrochemical water treatment systems for industrial and municipal water and wastewater treatment.
Abstract: Electrochemical processes have been extensively investigated for the removal of a range of organic and inorganic contaminants. The great majority of these studies were conducted using nitrate-, perchlorate-, sulfate-, and chloride-based electrolyte solutions. In actual treatment applications, organic and inorganic constituents may have substantial effects on the performance of electrochemical treatment. In particular, the outcome of electrochemical oxidation will depend on the concentration of chloride and bromide. Formation of chlorate, perchlorate, chlorinated, and brominated organics may compromise the quality of the treated effluent. A critical review of recent research identifies future opportunities and research needed to overcome major challenges that currently limit the application of electrochemical water treatment systems for industrial and municipal water and wastewater treatment. Given the increasing interest in decentralized wastewater treatment, applications of electrolytic systems for treat...
716 citations
TL;DR: Key challenges facing EAOP technologies are related to toxic byproduct formation and low electro-active surface areas and must be addressed in future research in order for EAOPs to realize their full potential for water treatment.
Abstract: Electrochemical advanced oxidation processes (EAOPs) have emerged as novel water treatment technologies for the elimination of a broad-range of organic contaminants. Considerable validation of this technology has been performed at both the bench-scale and pilot-scale, which has been facilitated by the development of stable electrode materials that efficiently generate high yields of hydroxyl radicals (OH˙) (e.g., boron-doped diamond (BDD), doped-SnO2, PbO2, and substoichiometic- and doped-TiO2). Although a promising new technology, the mechanisms involved in the oxidation of organic compounds during EAOPs and the corresponding environmental impacts of their use have not been fully addressed. In order to unify the state of knowledge, identify research gaps, and stimulate new research in these areas, this review critically analyses published research pertaining to EAOPs. Specific topics covered in this review include (1) EAOP electrode types, (2) oxidation pathways of select classes of contaminants, (3) rate limitations in applied settings, and (4) long-term sustainability. Key challenges facing EAOP technologies are related to toxic byproduct formation (e.g., ClO4− and halogenated organic compounds) and low electro-active surface areas. These challenges must be addressed in future research in order for EAOPs to realize their full potential for water treatment.
600 citations
References
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TL;DR: In this article, the electrochemical oxidation of phenol was studied using a packed bed reactor of pellets with recirculating anolyte in order to follow phenol loss and benzoquinone, maleic acid, and carbon dioxide formation.
Abstract: The electrochemical oxidation of phenol was studied using a packed bed reactor of pellets with recirculating anolyte in order to follow phenol loss and benzoquinone, maleic acid, and carbon dioxide formation. A carbon mass balance revealed a significant fraction of additional by‐products for initial phenol concentrations of ≥ 0.014M. Benzoquinone and carbon dioxide formation were measured as a function of applied current, initial phenol concentration, electrolyte acid concentration, temperature, and dissolved oxygen. Benzoquinone formation was favored by high current and acid concentration and by low phenol concentration, temperature, and dissolved oxygen at relatively short electrolysis times. Carbon dioxide formation depended on the degree of the oxidation and was favored by high current, acid concentration, temperature, dissolved oxygen, and by low phenol concentration.
141 citations
TL;DR: In this paper, the electrochemical oxidation of phenol for waste water treatment applications was investigated on lead dioxide packedbed anodes on both batch and continuous modes with feed streams up to 1100 mg/l phenol dissolved in aqueous solutions of Na2SO 4 and H2SO4 or NaOH.
Abstract: The electrochemical oxidation of phenol for waste water treatment applications was investigated on lead dioxide packedbed anodes. Cells were operated in both batch and continuous modes with feed streams up to 1100 mg/l phenol dissolved in aqueous solutions of Na2SO4 and H2SO4 or NaOH. All the phenol in solution could be readily oxidized but complete total organic carbon (T.O.C.) removal was more difficult. The percent phenol oxidized increased with increasing current density, and decreased as initial phenol concentration, electrolyte flow rate, pH and anode particle size were increased. Results are compared to simple mathematical models.
On a etudie l'oxydation electrochimique du phenol, susceptible d'applications dans le traitement des eaux usees, sur une colonne garnie d'anodes de dioxyde de plomb. On a fait fonctionner ces cellulesc, d'une maniere continue et d'une maniere discontinue, en utilisant des courants d'alimentation contenant jusqu'a 1000 milligrammes par litre de phenol dissous dans des solutions aqueuses de Na2SO4 et H2SO4 ou NaOH. On a pu ainsi oxyder facilement tout le phenol en solution, mais il a ete plus difficile d'enlever completement tout le carbone organique (T.O.C.). I.c pourcentage du phenol oxyde s'est accru avec I'augmentation de la densite de courant et a diminue avec un accroissement de la concentration initiale du phenol, du debit de l'electrolyte et des dimensions des particules a l'anode. On a compare les resultats avec les predictions de modeles mathematiques simples.
114 citations
TL;DR: The feasibility of electropolymerization of phenol(s) in oxalic acid solutions at different electrodes (Pt, graphite, Fe) was demonstrated by voltammetric experiments as discussed by the authors.
104 citations
TL;DR: The second-order rate constants for the microbial transformation of a series of phenols were correlated with physicochemical properties of the phenols as mentioned in this paper, and the results showed that van der Waal's radii gave the best coefficient of determination (r2 = 0.956).
Abstract: The second-order rate constants for the microbial transformation of a series of phenols were correlated with the physicochemical properties of the phenols. The compounds studied were phenol, p-methylphenol, p-chlorophenol, p-bromophenol, p-cyanophenol, p-nitrophenol, p-acetylphenol, and p-methoxyphenol. Phenol-grown cells of Pseudomonas putida U transformed these compounds. Microbial transformation rate constants ranged from (1.5 ± 0.99) × 10−14 liter · organism−1 · h−1 for p-cyanophenol to (7.0 ± 1.3) × 10−12 liter · organism−1 · h−1 for phenol. Linear regression analyses of rate constants and electronic, steric, and hydrophobic parameters showed that van der Waal's radii gave the best coefficient of determination (r2 = 0.956). Products identified by thin-layer chromatography and liquid chromatography indicated that the phenols were microbially oxidized to the corresponding catechols.
82 citations
TL;DR: In this article, the formation of polyoxyphenylene coatings onto Fe, Zn and Cu sheets by anodic oxidation of phenol/amine systems has been investigated and it was found that thick homogeneous coatings are obtained only when a suitable amine is present in the electrolysis solution.
Abstract: The formation of protective polyoxyphenylene coatings onto Fe, Zn and Cu sheets by anodic oxidation of phenol/amine systems has been investigated It was found that thick homogeneous coatings are obtained only when a suitable amine is present in the electrolysis solution The amine not only stops the anodic formation of passivating metal oxides which inhibit polymer growth, but also enters into the structure of the coatings The polymer chains obtained from phenols are, in fact, highly modified by amine molecules grafted onto the phenoxy units
68 citations