Journal articles: 'Oxidation. Ozone. Phenols'

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Lee, Jong-Pal, Nak-Chang Sung, Sung-Sik Lee, and Hyun-Seok Park. "Reactivity of Phenols in Ozone Oxidation Reaction." Journal of the Korean Chemical Society 47, no. 4 (August 20, 2003): 423–26. http://dx.doi.org/10.5012/jkcs.2003.47.4.423.

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Chen, Lei, Yanhua Xu, and Yongjun Sun. "Combination of Coagulation and Ozone Catalytic Oxidation for Pretreating Coking Wastewater." International Journal of Environmental Research and Public Health 16, no. 10 (May 15, 2019): 1705. http://dx.doi.org/10.3390/ijerph16101705.

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In this study, coagulation, ozone (O3) catalytic oxidation, and their combined process were used to pretreat actual coking wastewater. The effects on the removal of chemical oxygen demand (COD) and phenol in coking wastewater were investigated. Results showed that the optimum reaction conditions were an O3 mass flow rate of 4.1 mg min−1, a reaction temperature of 35 °C, a catalyst dosage ratio of 5:1, and a O3 dosage of 500 mg·L−1. The phenol removal ratio was 36.8% for the coagulation and sedimentation of coking wastewater under optimal conditions of 25 °C of reaction temperature, 7.5 reaction pH, 150 reaction gradient (G) value, and 500 mg·L−1 coagulant dosage. The removal ratios of COD and phenol reached 24.06% and 2.18%, respectively. After the O3-catalyzed oxidation treatment, the phenols, polycyclic aromatic hydrocarbons, and heterocyclic compounds were degraded to varying degrees. Coagulation and O3 catalytic oxidation contributed to the removal of phenol and COD. The optimum reaction conditions for the combined process were as follows: O3 dosage of 500 mg·L−1, O3 mass flow of 4.1 mg·min−1, catalyst dosage ratio of 5:1, and reaction temperature of 35 °C. The removal ratios of phenol and COD reached 47.3% and 30.7%, respectively.

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Yuan, B., J. Liggio, J. Wentzell, S. M. Li, H. Stark, J. M. Roberts, J. Gilman, et al. "Secondary formation of nitrated phenols: insights from observations during the Uintah Basin Winter Ozone Study (UBWOS) 2014." Atmospheric Chemistry and Physics Discussions 15, no. 20 (October 23, 2015): 28659–97. http://dx.doi.org/10.5194/acpd-15-28659-2015.

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Abstract. We describe the results from online measurements of nitrated phenols using a time of flight chemical ionization mass spectrometer (ToF-CIMS) with acetate as reagent ion in an oil and gas production region in January and February of 2014. Strong diurnal profiles were observed for nitrated phenols, with concentration maxima at night. Based on known markers (CH4, NOx, CO2), primary emissions of nitrated phenols were not important in this study. A box model was used to simulate secondary formation of phenol, nitrophenol (NP) and dinitrophenols (DNP). The box model results indicate that oxidation of aromatics in the gas phase can explain the observed concentrations of NP and DNP in this study. Photolysis was the most efficient loss pathway for NP in the gas phase. We show that aqueous-phase reactions and heterogeneous reactions were minor sources of nitrated phenols in our study. This study demonstrates that the emergence of new ToF-CIMS (including PTR-TOF) techniques allows for the measurement of intermediate oxygenates at low levels and these measurements improve our understanding of the evolution of primary VOCs in the atmosphere.

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Yuan, Bin, John Liggio, Jeremy Wentzell, Shao-Meng Li, Harald Stark, James M. Roberts, Jessica Gilman, et al. "Secondary formation of nitrated phenols: insights from observations during the Uintah Basin Winter Ozone Study (UBWOS) 2014." Atmospheric Chemistry and Physics 16, no. 4 (February 24, 2016): 2139–53. http://dx.doi.org/10.5194/acp-16-2139-2016.

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Abstract. We describe the results from online measurements of nitrated phenols using a time-of-flight chemical ionization mass spectrometer (ToF-CIMS) with acetate as reagent ion in an oil and gas production region in January and February of 2014. Strong diurnal profiles were observed for nitrated phenols, with concentration maxima at night. Based on known markers (CH4, NOx, CO2), primary emissions of nitrated phenols were not important in this study. A box model was used to simulate secondary formation of phenol, nitrophenol (NP), and dinitrophenols (DNP). The box model results indicate that oxidation of aromatics in the gas phase can explain the observed concentrations of NP and DNP in this study. Photolysis was the most efficient loss pathway for NP in the gas phase. We show that aqueous-phase reactions and heterogeneous reactions were minor sources of nitrated phenols in our study. This study demonstrates that the emergence of new ToF-CIMS (including PTR-TOF) techniques allows for the measurement of intermediate oxygenates at low levels and these measurements improve our understanding on the evolution of primary VOCs in the atmosphere.

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Sakakibara, Y., Y. Sena, and M. Prosnansky. "Direct oxidation treatment by a novel 3-dimensional electrolytic cell reactor." Water Supply 6, no. 2 (March 1, 2006): 87–91. http://dx.doi.org/10.2166/ws.2006.054.

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The\ performance of a novel 3-dimensional electrolytic cell reactor for the treatment of dilute solutions was investigated using different dyes (potassium indigotrisulfonate (PI), Orange 2 and Amaranth) and endocrine disrupting chemicals (EDCs). Continuous experiments demonstrated that the present electrolytic cell reactor was able to directly oxidize the dyes on the surface of the electrode very quickly in response to a change in electric current. It is interesting to note that the energy consumption for the oxidation of PI and Orange 2 was significantly smaller than for the commercially available ozone generators. The electrolytic reactor was also successfully applied to the treatment of trace EDCs including 17β-estradiol, bisphenol-A, nonyl-phenol and chlorinated phenols.

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Chaparro, T. R., and E. C. Pires. "Post-treatment of anaerobic effluent by ozone and ozone/UV of a kraft cellulose pulp mill." Water Science and Technology 71, no. 3 (December 26, 2014): 382–89. http://dx.doi.org/10.2166/wst.2014.527.

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Pulp and paper mill effluents represent a challenge when treatment technologies are considered, not only to reduce organic matter, but also to reduce the toxicological effects. Although anaerobic treatment has shown promising results, as well as advantages when compared with an aerobic system, this process alone is not sufficient to reduce recalcitrant compounds. Thus, an advanced oxidation process was applied. This experiment was performed to determine the effect of ozone and ozone/UV treating a horizontal anaerobic immobilized biomass reactor effluent from a kraft cellulose pulp mill for 306 days with an organic volumetric load of 2.33 kgCOD/m3/day. The removal of organic compounds was measured by the following parameters: adsorbable organically bound halogens (AOX), total phenols, chemical oxygen demand (COD), dissolved organic carbon and absorbance values in the UV-visible spectral region. Moreover, ecotoxicity and genotoxicity tests were conducted before and after treatment with ozone and ozone/UV. At an applied ozone dosage of 0.76 mgO3/mgCOD and an applied UV dosage of 3.427 Wh/m3, the organochlorine compounds measured as AOX reached removal efficiencies of 40%. Although the combination of ozone/UV showed better results in colour (79%) and total phenols (32%) compared with only ozone, the chronic toxicity and the genotoxicity that had already been removed in the anaerobic process were slightly increased.

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Amin, Nor Aishah Saidina, Javaid Akhtar, and H. K. Rai. "Catalytic ozonation of aqueous phenol over metal-loaded HZSM-5." Water Science and Technology 63, no. 8 (April 1, 2011): 1651–56. http://dx.doi.org/10.2166/wst.2011.313.

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The performances of HZSM-5 and transition metal-loaded HZSM-5 (Mn, Cu, Fe, Ti) catalysts during catalytic ozonation of phenol have been investigated. It was observed the performance order for removal of phenol and COD was Mn/HZSM-5>Fe/HZSM-5>Cu/HZSM-5>Ti/HZSM-5>HZSM-5. The presence of metals on HZSM-5 enhanced the phenol removal capability of HZSM-5. Mn loading on HZSM-5 was optimized due to its high phenol removal capability amongst metal-loaded HZSM-5 catalysts. Experimental results suggested that low amount of Mn loading on HZSM-5 was sufficient for HZSM-5 to act as catalyst and adsorbent. A maximum of 95.8 wt% phenols and 70.2 wt% COD were removed over 2 wt% Mn/HZSM-5 in 120 min. It was supposed that transition metals mainly acted as ozone decomposers due to their multiple oxidation states that enhanced the ozonation of phenol.

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Zeff, Jack D., and Jerome T. Barich. "UV/Oxidation of Organic Contaminants in Ground, Waste and Leachate Waters." Water Quality Research Journal 27, no. 1 (February 1, 1992): 139–50. http://dx.doi.org/10.2166/wqrj.1992.008.

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Abstract Over the past four years, Ultrox International has demonstrated the efficacy of ultraviolet light-enhanced oxidation at industrial, Department of Defense and Superfund sites. Waters containing halogenated solvents such as trichloroethylene, perchloroethylene and other halogenated compounds have been successfully treated with UV/ozone or UV/hydrogen peroxide or UV with ozone and peroxide. Other contaminants such as benzene, toluene, xylene, hydrazines, phenols, chlorophenols, dioxanes, PCBs and pesticides in wastewaters and groundwaters have also been reduced to acceptable discharge standards. Summations of the above projects will be presented, along with some of the technological basis of this process. Data showing comparisons of UV-enhanced oxidation testing with traditional ozonation also will be presented based upon research conducted under government grants. Design and cost data from pilot plant testing and from operations at full-scale commercial installations will be presented. The applications will cover ultraviolet/oxidation systems treating waste water in the wood treating industry, rocket fuel waste water, and groundwater containing chlorinated solvents at automotive, aerospace and electronics manufacturers. A discussion of test results and process economics from a demonstration of the ULTROX® process in the U.S. EPA Superfund Innovative Technology Evaluation (SITE) Program also will be presented.

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9

Oputu, Ogheneochuko Utieyin, Olalekan Siyabonga Fatoki, Beatrice Olutoyin Opeolu, and Michael Ovbare Akharame. "Degradation Pathway of Ozone Oxidation of Phenols and Chlorophenols as Followed by LC-MS-TOF." Ozone: Science & Engineering 42, no. 4 (September 9, 2019): 294–318. http://dx.doi.org/10.1080/01919512.2019.1660617.

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10

Solanki, V. S., B. Pare, P. Gupta, S. B. Jonnalagadda, and R. Shrivastava. "A Review on Advanced Oxidation Processes (AOPs) for Wastewater Remediation." Asian Journal of Chemistry 32, no. 11 (October 28, 2020): 2677–84. http://dx.doi.org/10.14233/ajchem.2020.22806.

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In 21st century, organic and domestic wastes and discharges from varied chemical and manufacturing industries to water bodies become a critical issue and challenge for the researchers, engineers and policy makers. Advanced oxidation processes (AOPs) are efficient, sustainable, economically viable and green techniques to elimination on-degradable organic pollutants by biological and traditional processes. A number of research articles have been published from the past two decades on the wastewater treatment using various advanced oxidation processes. The main objective of this review paper is to provide the quick view for researchers, academicians and scientists in the area of wastewater treatment using various types of AOPs, which incorporate green principles involves in the processes for removal of different pollutants and contaminants including dyes, phenols, pesticides, herbicides etc. from wastewaters, with emphasis on the degradation efficiency of various photocatalysts. The formation reactions of •OH radical and the mechanisms of degradation of various organic pollutants in the wastewater is also discussed. This review covers various types of advanced oxidation processes, viz., ozone-based processes, photocatalysis and Fenton-based reactions.

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Duguet, J. P., B. Dussert, J. Mallevialle, and F. Fiessinger. "Polymerization Effects of Ozone: Applications to the Removal of Phenolic Compounds from Industrial Wastewaters." Water Science and Technology 19, no. 5-6 (May 1, 1987): 919–30. http://dx.doi.org/10.2166/wst.1987.0270.

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Degradation of phenols by ozone has been extensively studied but the oxidative coupling pathway of ozone resulting in a phenol polymerization has not been largely investigated. Application of low ozone dose in solutions of 2.4 dichlorophenol and salicylic acid is characterized by the formation of high molecular compounds which are partially insoluble. Numerous polymers have been identified by gas chromatography coupled with mass spectrometry. Application of the polymerization effect of ozone to petrochemical and coking wastewaters containing phenols give similar results. In each case, phenolic compounds are efficiently removed, even if a large organic content is present. In the case of petrochemical wastewater, where phenols represent only 30% of TOC, the ozone effects are not sufficient to merit an ozonation step on the present treatment line. On the other hand, when phenols represent the greater part of the organics, as in coking wastewater, an important fraction of insoluble compounds, easily removed by filtration, are formed.

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Teo, K. C., C. Yang, R. J. Xie, N. K. Goh, and L. S. Chia. "Destruction of model organic pollutants in water using ozone, UV and their combination (Part I)." Water Science and Technology 47, no. 1 (January 1, 2003): 191–96. http://dx.doi.org/10.2166/wst.2003.0051.

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The experimental results showed that ozone (O3) oxidation is an effective means to destroy phenolic organic pollutants present in water. High removal efficiencies can be readily achieved for most of the model compounds fortified in aqueous matrices within a reasonable time frame. This study also included the oxidation of phenolic compounds using ozone in combination with ultraviolet (UV) irradiation. The extent of mineralization measured in terms of the losses in total organic carbon is promoted by the joint action of ozone and UV in comparison with using ozone alone.

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13

Oh, B. S., K. S. Kim, and J. W. Kang. "Ozonation of haloacetic acid precursor using phenol as a model compound: effect of ozonation by-products." Water Supply 6, no. 2 (March 1, 2006): 215–22. http://dx.doi.org/10.2166/ws.2006.072.

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The formation pattern of haloacetic acids (HAAs) was investigated using phenol as a model precursor of HAAs, and the oxidation by-products formed from phenol ozonation, such as hydroquinone, catechol, glyoxal, glyoxylic acid and oxalic acid, were also chlorinated to measure the HAAs formation potential (HAAFP). Of these, phenol showed the highest reactivity with chlorine, yielding the most HAAFP. Even though HAAFP of the tested by-products was lower than that of phenol, it was confirmed that all by-products can act as the precursor of HAAs. Regarding the ozonation of phenol-containing water, the efficiency of ozone in controlling HAAs can be reduced by the formation of oxidation by-products. When comparing conditions for pH 7 and 3, the ozonation for pH 7 was more effective in removing the overall HAA precursors than the ozonation for pH 3. This result was attributed to complete oxidation by the production of the secondary oxidant, such as the OH radical (OH·) from ozone decay, and ionization of phenol.

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Narkis, Nava, Bella Ben-David, and Malka Schneider Rotel. "Ozonation of Non-Ionic Surfactants in Aqueous Solutions." Water Science and Technology 17, no. 6-7 (June 1, 1985): 1069–80. http://dx.doi.org/10.2166/wst.1985.0202.

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The effect of ozone on dilute aqueous solutions of a series of non-ionic surfactants of nonyl phenol ethoxylates, with n=4 to 30 ethylene oxide groups, dinonyl phenol ethoxylate and a polyethylene glycol were investigated. Assuming ozone concentration in solution to remain constant throughout the ozonation, the experiments showed first-order reactions with respect to surfactant concentration, as measured by the Wickbold method, and also with respect to COD & TOC. A linear relationship was established between the first-order reaction rate constants, and between n, the average number of ethylene oxide groups in the ethoxylate chain of the nonyl phenol ethoxylate series. The oxidation mechanism by ozone of non-ionic surfactant molecules is explained as mainly polyethoxylate chains' cleavage into shorter polyethylene glycols and to a smaller extent oxidation of the aromatic ring. High ozone doses do not convert the non-ionic surfactant completely to CO2 and H2O but smaller doses are sufficient to enhance biodegradation.

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Chand, Rashmi, Raul Molina, Ian Johnson, Anna Hans, and David H. Bremner. "Activated carbon cloth: a potential adsorbing/oxidizing catalyst for phenolic wastewater." Water Science and Technology 61, no. 11 (June 1, 2010): 2817–23. http://dx.doi.org/10.2166/wst.2010.091.

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An investigation into the use of activated carbon cloth (ACC) as a potential adsorbent and/or catalyst for oxidation processes is reported. The extent of increase/decrease of oxidation/adsorption of phenol, as measured by total organic carbon content (%), is explained by considering the effects of the oxidants such as ozone and hydrogen peroxide on the activated carbon cloth. Results also show that acid pH enhances the catalytic decomposition of H2O2 to hydroxyl radicals, increasing TOC removal from 16 to 55% as a result of oxidation of phenol in addition to adsorption on the ACC surface. Furthermore when using ACC catalysis under optimized conditions, the maximum extent of TOC elimination is approximately 70% with three 15 min doses of ozone at pH 9.

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Okouchi, S., O. Nojima, and T. Arai. "Cavitation-Induced Degradation of Phenol by Ultrasound." Water Science and Technology 26, no. 9-11 (November 1, 1992): 2053–56. http://dx.doi.org/10.2166/wst.1992.0659.

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Aqueous solution of phenol was irradiated with ultrasonic waves of sufficient intensity to induce cavitation. The phenol was exponentially degradated, because of the formation of reactive species produced by water decomposition and reaction with water and oxygen. The degradation pathway for phenol was similar to that of the phenol oxidation with ozone.

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El-Midany, Ayman A., Reda M. Mohamed, and Ibrahim A. Ibrahim. "Statistical Evaluation of Phenol Degradation by Ozone Oxidation." Materials Testing 56, no. 3 (March 3, 2014): 251–54. http://dx.doi.org/10.3139/120.110551.

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18

Wu, Jiangning, Klaas Rudy, and Josef Spark. "Oxidation of aqueous phenol by ozone and peroxidase." Advances in Environmental Research 4, no. 4 (November 2000): 339–46. http://dx.doi.org/10.1016/s1093-0191(00)00034-4.

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Bettazzi, E., C. Caretti, S. Caffaz, E. Azzari, and C. Lubello. "Oxidative processes for olive mill wastewater treatment." Water Science and Technology 55, no. 10 (May 1, 2007): 79–87. http://dx.doi.org/10.2166/wst.2007.309.

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The present work describes an experimental study carried out in order to investigate the efficiency and feasibility of physical (lime coagulation) and advanced oxidation processes (Ozone and Fenton's process) for olive oil mill wastewater treatment. Particular attention was paid to the degradation of both organic and phenolic compounds. Lime coagulation reaches maximum removal at a pH of 12, with a TP (total polyphenols) and COD reduction of 37 and 26%, respectively. Ozone oxidation is also pH-dependent, showing the higher removal efficiency (91% for TP and 19% for COD) with an initial pH value of 12. Experimental results show a lower efficiency of Fenton's process than ozone in TP removal, reaching a maximum value of 60%. Oxidation trials carried out on gallic and p-coumaric synthetic solutions confirmed ozone and Fenton's efficiency at degrading phenolic compounds. Biological trials, both aerobic and anaerobic, highlighted a significant increase of biodegradability of treated OMW samples if compared to the untreated ones. Respirometric tests showed an increase in BOD of about 20% and anaerobic batch tests provided a methane production up to eight times higher.

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Mokrini, A., D. Ousse, and S. Esplugas. "Oxidation of aromatic compounds with UV radiation/ozone/hydrogen peroxide." Water Science and Technology 35, no. 4 (February 1, 1997): 95–102. http://dx.doi.org/10.2166/wst.1997.0095.

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A large variety of organic and inorganic compounds may be found in wastewater. Among these compounds, aromatics are characterized by their high toxicity and very low degradability by conventional treatments. This paper presents the results of an investigation about the oxidation of two substituted benzenes in a semi-batch reactor: phenol, substituted with an electron-donating group (-OH), and benzoic acid substituted with an electron- withdrawing group (-COOH). The advanced oxidation processes studied were UV, ozone, hydrogen peroxide and its combinations. The pH dependence and the influence of the initial concentration of hydrogen peroxide were studied to find the optimal conditions for a complete and fast oxidation of both compounds. Experimental results indicated that both phenol and benzoic acid are destroyed more rapidly by ozone at higher pH (9–12), while ozonation combined with hydrogen peroxide or/and UV is considerably faster at low pH (3–7).

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Bubica Bustos, Ludmila M., Andrea C. Ueno, Tara D. Di Leo, Carlos D. Crocco, M. Alejandra Martínez-Ghersa, Marco A. Molina-Montenegro, and Pedro E. Gundel. "Maternal Exposure to Ozone Modulates the Endophyte-Conferred Resistance to Aphids in Lolium multiflorum Plants." Insects 11, no. 9 (August 19, 2020): 548. http://dx.doi.org/10.3390/insects11090548.

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Plants are challenged by biotic and abiotic stress factors and the incidence of one can increase or decrease resistance to another. These relations can also occur transgenerationally. For instance, progeny plants whose mothers experienced herbivory can be more resistant to herbivores. Certain fungal endophytes that are vertically transmitted endow plants with alkaloids and resistance to herbivores. However, endophyte-symbiotic plants exposed to the oxidative agent ozone became susceptible to aphids. Here, we explored whether this effect persists transgenerationally. We exposed Lolium multiflorum plants with and without fungal endophyte Epichloë occultans to ozone (120 or 0 ppb), and then, challenged the progeny with aphids (Rhopalosiphum padi). The endophyte was the main factor determining the resistance to aphids, but its importance diminished in plants with ozone history. This negative ozone effect on the endophyte-mediated resistance was apparent on aphid individual weights. Phenolic compounds in seeds were increased by the symbiosis and diminished by the ozone. The endophyte effect on phenolics vanished in progeny plants while the negative ozone effect persisted. Independently of ozone, the symbiosis increased the plant biomass (≈24%). Although ozone can diminish the importance of endophyte symbiosis for plant resistance to herbivores, it would be compensated by host growth stimulation.

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Wang, Rui, Chen-Loung Chen, and Josef S. Gratzl. "Ozonation of pine kraft lignin in alkaline solution. Part 1: Ozonation, characterization of kraft lignin and its ozonated preparations." Holzforschung 58, no. 6 (October 1, 2004): 622–30. http://dx.doi.org/10.1515/hf.2004.116.

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Abstract Pine kraft lignin was purified to obtain a kraft lignin preparation (KL) with weight average molecular mass (Mw) of 5500. The KL was then ozonated with an ozone-air stream containing 2–2.5% of ozone in 0.1 M sodium hydroxide solution to prepare ozonated kraft lignin preparations with ozone consumption of 10, 25, 30 and 40% per KL; Oz-10-KL, Oz-25-KL, Oz-30-KL and Oz-40-KL, respectively. The pH of reaction mixture was decreased with increasing ozone consumption, while the carboxylic acid content and the Mw of resulting ozonated lignins increase with increasing ozone consumption. The KL and its ozonated preparations were then characterized by elemental composition, functional group analysis, molecular mass distribution and nitrobenzene-K4MnO4 oxidation. The results showed that the KL extensively undergoes oxidative cleavage of both side chains and aromatic moieties without decrease in the Mw as well as dehydrogenationive coupling of phenolic degraded fragments by active oxygen radical species, such as hydroperoxyl and hydroxyl radicals. The formation of these active oxygen radical species are produced by way of a series of reactions initiated by the reaction of ozone with hydroxide anions at pH range of 12.4–10.5, producing superoxide (-O2•) and hydroperoxyl (HOO•) radicals.

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Ratnawati, R., E. Enjarlis, Yuli Amalia Husnil, Marcelinus Christwardana, and S. Slamet. "Degradation of Phenol in Pharmaceutical Wastewater using TiO2/Pumice and O3/Active Carbon." Bulletin of Chemical Reaction Engineering & Catalysis 15, no. 1 (November 22, 2019): 146–54. http://dx.doi.org/10.9767/bcrec.15.1.4432.146-154.

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Phenol is a toxic organic compound that detectable in the pharmaceutical wastewater, and therefore it should be eliminated. This study aims to degrade phenol in the pharmaceutical wastewater treatment using Advanced Oxidation Processes (AOPs) include the photocatalytic process applying Titanium Oxide (TiO2) that immobilized on pumice stone (PS), as well as ozone process with O3 and O3/granulated activated carbon (GAC). Degradation system used two configuration reactors that worked alternately at pH 3 and 9. Photocatalysis was conducted for 4 hours in the photoreactor that equipped with mercury lamp as a photon source, while ozonation was performed for 1 hour in the cylinder glass reactor contained an ozone generator. Phenol degradations were done by photocatalysis, ozonation, photocatalysis followed by ozonation and vice versa. The FESEM-EDS and XRD results depicted that TiO2 has impregnated on pumice stone and FESEM characterization also indicated that the photocatalyst spread across the surface of the pumice stone. BET analysis results in an increased surface area of the PS-TiO2 by 3.7 times, whereas bandgap energy down to 3 eV. It can be concluded that ozone process (with O3/GAC) that followed by photocatalysis at pH 9 could treat the liquid waste with phenol concentration 11.2 down to 1.2 ppm that nearly according to the discharge standards quality (1 ppm). Copyright © 2020 BCREC Group. All rights reserved

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Yue, P. L., and O. Legrini. "Photochemical Degradation of Organics in Water." Water Quality Research Journal 27, no. 1 (February 1, 1992): 123–38. http://dx.doi.org/10.2166/wqrj.1992.007.

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Abstract Trichloroethylene, phenol, 4-cholorophenol, catechol and a pesticide were degraded by two advanced oxidation processes: photolytic oxidation with hydrogen peroxide, andphotolytic oxidation with ozone. The reactions were studied in a batch photoreactor with a low pressure mercury lamp as the radiation source. The variation of the concentration of total organic carbon with time was measured. For the organics studied, the reaction kinetics for the reduction of total organic carbon (TOC) were found to follow a power law. The exponent of the power law varies with the initial TOC concentration. Results show that TOC can be very effectively reduced provided the concentration of hydrogen peroxide used exceeds a certain threshold value. The UV/Ozone process yielded a more rapid rate of degradation and a greater degree of mineralisation.

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Qing-Yun, Chen, Shi Dong-Dong, Zhang Yuan-Jun, and Wang Yun-Hai. "Phenol degradation on novel nickel-antimony doped tin dioxide electrode." Water Science and Technology 62, no. 9 (November 1, 2010): 2090–95. http://dx.doi.org/10.2166/wst.2010.401.

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Nickel and antimony doped tin dioxide is a novel anodic material for its good performance of electrochemical ozone generation and direct electro-catalytic oxidation. Electro-catalytic oxidation of phenol on this novel nickel-antimony doped tin dioxide electrode is presented here. The morphology and composition of the electrode are characterized. The effects of applied current densities on phenol degradation rate, energy consumption and coulomb efficiency are discussed. In 0.1 M sulfuric acid, after 4 h electrolysis with current density of 25 mA cm−1, 90% phenol is removed. And with current density of 20 mA cm−1, the highest energy efficiency of 6.85 g kWh−1 and the highest coulomb efficiency of 6.87 μg C−1 are obtained. The effect of current densities on TOC removal is also discussed.

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Ferreiro, Cristian, Ana de Luis, Natalia Villota, Jose Lomas, José Lombraña, and Luis Camarero. "Application of a Combined Adsorption−Ozonation Process for Phenolic Wastewater Treatment in a Continuous Fixed-Bed Reactor." Catalysts 11, no. 8 (August 22, 2021): 1014. http://dx.doi.org/10.3390/catal11081014.

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This work studied the removal of phenol from industrial effluents through catalytic ozonation in the presence of granular activated carbon in a continuous fixed-bed reactor. Phenol was chosen as model pollutant because of its environmental impact and high toxicity. Based on the evolution of total organic carbon (TOC) and phenol concentration, a kinetic model was proposed to study the effect of the operational variables on the combined adsorption–oxidation (Ad/Ox) process. The proposed three-phase model expressed the oxidation phenomena in the liquid and the adsorption and oxidation on the surface of the granular activated carbon in the form of two kinetic constants, k1 and k2 respectively. The interpretation of the constants allow to study the benefits and behaviour of the use of activated carbon during the ozonisation process under different conditions affecting adsorption, oxidation, and mass transfer. Additionally, the calculated kinetic parameters helped to explain the observed changes in treatment efficiency. The results showed that phenol would be completely removed at an effective contact time of 3.71 min, operating at an alkaline pH of 11.0 and an ozone gas concentration of 19.0 mg L−1. Under these conditions, a 97.0% decrease in the initial total organic carbon was observed.

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TAKAHASHI, Nobuyuki, and Osamu KATSUKI. "Oxidative decompositions of phenol and ethylene glycol by ozone." NIPPON KAGAKU KAISHI, no. 5 (1987): 862–69. http://dx.doi.org/10.1246/nikkashi.1987.862.

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Hurtado, Lourdes, Deysi Amado-Piña, Gabriela Roa-Morales, Ever Peralta-Reyes, Eduardo Martin del Campo, and Reyna Natividad. "Comparison of AOPs Efficiencies on Phenolic Compounds Degradation." Journal of Chemistry 2016 (2016): 1–8. http://dx.doi.org/10.1155/2016/4108587.

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In this work, a comparison of the performances of different AOPs in the phenol and 4-chlorophenol (4-CP) degradation at lab and pilot scale is presented. It was found that, in the degradation of phenol, the performance of a coupled electro-oxidation/ozonation process is superior to that observed by a photo-Fenton process. Phenol removal rate was determined to be 0.83 mg L−1 min−1 for the coupled process while the removal rate for photo-Fenton process was only 0.52 mg L−1 min−1. Regarding 4-CP degradation, the complete disappearance of the molecule was achieved and the efficiency decreasing order was as follows: coupled electro-oxidation/ozonation > electro-Fenton-like process > photo-Fenton process > heterogeneous photocatalysis. Total organic carbon was completely removed by the coupled electro-oxidation/ozonation process. Also, it was found that oxalic acid is the most recalcitrant by-product and limits the mineralization degree attained by the technologies not applying ozone. In addition, an analysis on the energy consumption per removed gram of TOC was conducted and it was concluded that the less energy consumption is achieved by the coupled electro-oxidation/ozonation process.

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Bartalis, Ildiko, Ilie Siminiceanu, and Eszter Arany. "ENHANCEMENT OF PHENOL OXIDATION BY OZONE IN WASTEWATER. II: KINETIC MODELING." Environmental Engineering and Management Journal 11, no. 2 (2012): 449–55. http://dx.doi.org/10.30638/eemj.2012.056.

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30

Lin, S. H., and C. H. Wang. "Adsorption and catalytic oxidation of phenol in a new ozone reactor." Environmental Technology 24, no. 8 (August 2003): 1031–39. http://dx.doi.org/10.1080/09593330309385642.

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31

Marchica, Alessandra, Lorenzo Cotrozzi, Rebecca Detti, Giacomo Lorenzini, Elisa Pellegrini, Maike Petersen, and Cristina Nali. "The Biosynthesis of Phenolic Compounds Is an Integrated Defence Mechanism to Prevent Ozone Injury in Salvia officinalis." Antioxidants 9, no. 12 (December 14, 2020): 1274. http://dx.doi.org/10.3390/antiox9121274.

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Specialized metabolites constitute a major antioxidant system involved in plant defence against environmental constraints, such as tropospheric ozone (O3). The objective of this experiment was to give a thorough description of the effects of an O3 pulse (120 ppb, 5 h) on the phenylpropanoid metabolism of sage, at both biochemical and molecular levels. Variable O3-induced changes were observed over time among the detected phenylpropanoid compounds (mostly identified as phenolic acids and flavonoids), likely because of their extraordinary functional diversity. Furthermore, decreases in the phenylalanine ammonia-lyase (PAL), phenol oxidase (PPO), and rosmarinic acid synthase (RAS) activities were reported during the first hours of treatment, probably due to an O3-induced oxidative damage to proteins. Both PAL and PPO activities were also suppressed at 24 h from the beginning of exposure, whereas enhanced RAS activity occurred at the end of treatment and at the recovery time, suggesting that specific branches of the phenolic pathways were activated. The increased RAS activity was accompanied by the up-regulation of the transcript levels of genes like RAS, tyrosine aminotransferase, and cinnamic acid 4-hydroxylase. In conclusion, sage faced the O3 pulse by regulating the activation of the phenolic biosynthetic route as an integrated defence mechanism.

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Luvita, Veny, Setijo Bismo, and Anto Tri Sugiarto. "Design and Performance Test of Ozone-Plasma Hybrid Reactor for Phenol Waste." Key Engineering Materials 885 (May 2021): 33–37. http://dx.doi.org/10.4028/www.scientific.net/kem.885.33.

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The research on phenolic compound degradation using chemical oxidation methods in a plasma reactor was performed with an Ozone-Plasma Hybrid Reactor (RHOP). This device operates by combining ozonation reactions in the liquid plasma within the reaction room. Furthermore, Ozone gas as a reagent is produced by the standard ozonator type Resun RSO-9805 made in Hong Kong and fed into this device, where the liquid phase is mixed within the injector. This way, the two-phase mixture reacts more intensively in RHOP. Also, this combination is designed to intensify hydroxyl radicals while the liquid phase is in an alkaline condition constantly exposed to plasma. The results demonstrated a continuous circulation for 2 hours at the initial concentration of 50 ppm for p-chlorophenol with a volume of 2 liters. This further obtained an 83.98% removal rate and 42.19% COD value decrease.

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33

Preis, S., I. C. Panorel, I. Kornev, H. Hatakka, and J. Kallas. "Pulsed corona discharge: the role of ozone and hydroxyl radical in aqueous pollutants oxidation." Water Science and Technology 68, no. 7 (October 1, 2013): 1536–42. http://dx.doi.org/10.2166/wst.2013.399.

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Ozone and hydroxyl radical are the most active oxidizing species in water treated with gas-phase pulsed corona discharge (PCD). The ratio of the species dependent on the gas phase composition and treated water contact surface was the objective for the experimental research undertaken for aqueous phenol (fast reaction) and oxalic acid (slow reaction) solutions. The experiments were carried out in the reactor, where aqueous solutions showered between electrodes were treated with 100-ns pulses of 20 kV voltage and 400 A current amplitude. The role of ozone increased with increasing oxygen concentration and the oxidation reaction rate. The PCD treatment showed energy efficiency surpassing that of conventional ozonation.

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34

Ji, Yuemeng, Jun Zhao, Hajime Terazono, Kentaro Misawa, Nicholas P. Levitt, Yixin Li, Yun Lin, et al. "Reassessing the atmospheric oxidation mechanism of toluene." Proceedings of the National Academy of Sciences 114, no. 31 (July 17, 2017): 8169–74. http://dx.doi.org/10.1073/pnas.1705463114.

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Photochemical oxidation of aromatic hydrocarbons leads to tropospheric ozone and secondary organic aerosol (SOA) formation, with profound implications for air quality, human health, and climate. Toluene is the most abundant aromatic compound under urban environments, but its detailed chemical oxidation mechanism remains uncertain. From combined laboratory experiments and quantum chemical calculations, we show a toluene oxidation mechanism that is different from the one adopted in current atmospheric models. Our experimental work indicates a larger-than-expected branching ratio for cresols, but a negligible formation of ring-opening products (e.g., methylglyoxal). Quantum chemical calculations also demonstrate that cresols are much more stable than their corresponding peroxy radicals, and, for the most favorable OH (ortho) addition, the pathway of H extraction by O2 to form the cresol proceeds with a smaller barrier than O2 addition to form the peroxy radical. Our results reveal that phenolic (rather than peroxy radical) formation represents the dominant pathway for toluene oxidation, highlighting the necessity to reassess its role in ozone and SOA formation in the atmosphere.

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Sano, Noriaki, Takuji Yamamoto, Hiroki Shinomiya, Akira Endo, Apiluck Eiad-Ua, Apinan Soottitantawat, Tawatchai Charinpanitkul, Wiwut Tanthapanichakoon, Takao Ohmori, and Hajime Tamon. "Decomposition of Phenol in Water by Ozone Oxidation with Metal-Supported Carbongel." JOURNAL OF CHEMICAL ENGINEERING OF JAPAN 42, Supplement. (2009): s17—s22. http://dx.doi.org/10.1252/jcej.08we130.

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36

Gulyas, H., K. Breuer, B. Lindner, and R. Otterpohl. "Screening of chemical oxidation processes and other methods for decolorization of urine for its re-use as toilet-flush liquid in ecological sanitation systems." Water Science and Technology 49, no. 4 (February 1, 2004): 241–46. http://dx.doi.org/10.2166/wst.2004.0273.

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Because of its potential use as fertilizer, urine (“yellow water”) is a resource originating from sanitation. Its separate collection in no-mix toilets is a beneficial aspect of ecological (source control) sanitation. In order to avoid dilution of the fertilizing nutrients with toilet flush water, the utilization of yellow water as toilet flush liquid seems to be advantageous. To be accepted for this purpose, urine has to be decolorized (and also deodorized). In this study activated carbon adsorption, irradiation with UV light of different wavelengths, the advanced oxidation processes ultrasound, UV/H2O2, and photocatalytic oxidation have failed to decolorize urine. Biological treatment caused brown colour of the treated urine. Only ozonation was successful in colour removal, although it did not affect TOC. In spite of darkening of yellow water during biological treatment (generation of humic substances), smaller ozone doses were required for decolorizing the biologically pre-treated urine than for original urine. Photocatalytic oxidation of biologically treated urine also removed brown colour, but the original yellow colour remained. In ozonated urine, yellow colour was reconstituted unless hydrogen peroxide was added. In addition to colour removal, ozone contributed to deodorization as a consequence of ammonia stripping and probably of phenol oxidation.

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Chung, S. J., S. Balaji, M. Matheswaran, T. Ramesh, and I. S. Moon. "Preliminary studies using hybrid mediated electrochemical oxidation (HMEO) for the removal of persistent organic pollutants (POPs)." Water Science and Technology 55, no. 1-2 (January 1, 2007): 261–66. http://dx.doi.org/10.2166/wst.2007.055.

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This study investigates the hybrid mediated electrochemical oxidation (HMEO) technology, which is a newly developed non thermal electrochemical oxidation process for organic destruction. A combination of ozone and ultrasonication processes to the mediated electrochemical oxidation (MEO) process is termed as hybrid mediated electrochemical oxidation. The electrochemical cell was developed in this laboratory. In the present study, several organic compounds, such as phenol, benzoquinone and ethylenediaminetetraacetic acid (EDTA), were chosen as the model organic pollutants to be destructed by the hybrid process. The organic destruction was monitored based on the CO2 generation and total organic carbon (TOC) reduction. The HMEO process was found to be extremely effective in the destruction of all the target organics chosen in this study. The information obtained from this study will provide an insight in adopting this technique for dealing with more recalcitrant organics (POPs).

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38

Chen, Shuang Kou, Jian Fang Zhu, Wen Zhang Huang, Bai He, Li Jun Xiang, and Upendra Adhikari. "Theoretical Study on the Properties of Phenol and its Ozonide." Advanced Materials Research 554-556 (July 2012): 1613–17. http://dx.doi.org/10.4028/www.scientific.net/amr.554-556.1613.

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Adopting BYLP method in Density Functional Theory (DFT), we make theoretical study on the ozonide-orthophenylphenol, parachlorophenol, orthobenzoquinone and parabenzoquinone in the two reaction routes of phenol oxidizing into benzoquinone with ozone. We get the geometric configuration of molecules, charge distribution of atoms, thermodynamical properties and frontier orbit energy. Natural Bond Orbital(NBO)charge calculation shows that compared with orthobenzoquinone and parabenzoquinone molecules, phenol, orthophenylphenol and parachlorophenol molecules have stronger reactivity and they are more likely to have electrophilic substitution reaction. Thermodynamic properties indicate that phenol is easy to have oxidation reaction and produce orthophenylphenol which is easily to oxidize into orthobenzoquinone no matter at low temperature, room temperature or high temperature. Another reaction pathwaycalculation shows that in thermodynamics, phenol will not easily ozonize into parachlorophenol; while parachlorophenol will easily ozonize into parabenzoquinone. Frontier orbit energy calculation shows that phenol, orthophenylphenol, and parachlorophenol show similar stability. Orthobenzoquinone and parabenzoquinone have the strongest stability.

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39

Seredyńska-Sobecka, Bożena, and Maria Tomaszewska. "The influence of ozonation on the activated carbon adsorption of phenol and humic acid." Polish Journal of Chemical Technology 9, no. 4 (December 1, 2007): 107–10. http://dx.doi.org/10.2478/v10026-007-0101-0.

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The influence of ozonation on the activated carbon adsorption of phenol and humic acid To study the influence of ozonation on the activated carbon adsorption, a model solution containing approximately 8 mg/dm3 of humic acid and approximately 1 mg/dm3 of phenol has been ozonated, and then adsorption kintetics and adsorption isotherm experiments have been performed. The applied ozone doses ranged from 1 to 3 mg O3/dm3, and a contact time was 1 min. In the adsorption experiments, the commercial activated carbon CWZ-30 (Gryfskand Sp. z o.o., Hajnówka, Poland) has been used. Phenol adsorption under equilibrium conditions was determined by the Freundlich isotherm equation, and the modified Freudlich isotherm equation has been employed for the determination of humic acid equilibrium adsorption. The applied oxidation conditions resulted in color, chemical oxygen demand (COD), total organic carbon (TOC) and UV254 absorbance removal, by 4 - 13%, 3 - 6%, 3 - 7%, respectively. After ozonation, phenol concentration decreased by 6 - 23%. These changes in the model solution did not affect the humic acid adsorption, however, they deteriorated phenol adsorption.

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40

Lesko, T., A. J. Colussi, and M. R. Hoffmann. "Sonochemical decomposition of phenol: evidence for a synergistic effect of ozone and ultrasound for the elimination of total organic carbon." Water Supply 6, no. 3 (July 1, 2006): 71–78. http://dx.doi.org/10.2166/ws.2006.795.

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The degradation of phenol (C6H5OH) was investigated under sonication, ozonation, and the combination of sonication and ozonation. The coupling of these two oxidation processes yielded phenol degradation kinetics that are similar to those predicted from the linear combination of the individual sonication and ozonation experiments. However, synergistic effects of sonolytic ozonation were observed for the reduction of the total organic carbon (TOC) in these systems. The rate of TOC decomposition was found to be proportional to both the aqueous steady-state ozone concentration and the ultrasonic power density. At 358 kHz, sonication combined with ozonation enhanced TOC loss rates by 43% over the sum of the rates obtained by the separate treatments. Intermediate species detected during the degradation of phenol indicate that while the primary degradation products are efficiently degraded by simple ozonolysis, the simultaneous addition of ultrasonic irradiation is necessary to degrade the more recalcitrant unsaturated daughter products.

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41

Cambie, Richard C., Maria do Céu Costa, Paul D. Woodgate, Peter S. Rutledge, Ni Na Kong, Clifford E. F. Rickard, Hantao Lu, and Michael R. Metzler. "Oxidations of 12-Deoxy-, 12-Hydroxy-, 12-Methoxy-, and 12-Hydroxy-13-methoxy-podocarpa-8,11,13-triene Derivatives." Australian Journal of Chemistry 51, no. 1 (1998): 37. http://dx.doi.org/10.1071/c97046.

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Methods for the oxidation of the aryl ring of derivatives of podocarpic acid have been examined. Oxidation of methyl 12-hydroxypodocarpa-8,11,13-trien-19-oate (2) with phenyliodonium diacetate in various solvents gives 8β-substituted dienones. An 8β-chloro dienone is formed during oxidation of the phenol (2) with t-butyl hypochlorite. Oxidation of (2) with dimethyldioxiran gives mainly the 7-ketone (13) but also affords the novel ε-lactone (26), while treatment with ruthenium tetraoxide also affords products of benzylic oxidation. Oxidation of methyl podocarpa-8,11,13-trien-19-oate (4) with m-chloroperbenzoic acid affords a B-ring lactone (29) and, unexpectedly, a 6α-chloro 7-ketone (30). The action of cerium(IV) ammonium nitrate on (2) gives nitro derivatives rather than oxidation products. Oxidation of methyl 12-hydroxy-13-methoxypodocarpa-8,11,13-trien-19-oate (22) with m-chloroperbenzoic acid gives a low yield of a 7-oxo derivative (17) while treatment with ozone gives an unusual α,β-unsaturated γ-lactone (31), the hydroxy lactone (33), the unsaturated keto ester (34), and the substituted furan (35). Oxidation of (22) with Fremy"s salt gives products of ring B oxidation. The structure of (31) has been confirmed by X-ray crystallography.

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42

Alekseeva, O. V., and S. D. Razumovskii. "Kinetics of phenol oxidation with ozone in a thin layer on a solid surface." Kinetics and Catalysis 47, no. 4 (July 2006): 533–36. http://dx.doi.org/10.1134/s0023158406040082.

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43

Yu, C. P., and Y. H. Yu. "Identifying useful real-time control parameters in ozonation process." Water Science and Technology 42, no. 3-4 (August 1, 2000): 435–40. http://dx.doi.org/10.2166/wst.2000.0415.

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Industrial wastewaters that contain phenolic compounds are resistant to biodegradation and need preoxidation to improve their biodegradabilities. Preoxidation of these wastewaters by using ozone as the chemical oxidant has been found previously to be quite effective in promoting their biodegradability. In combined ozonation and biological processes, if we want to stop ozonation at the optimum condition (i.e. the maximum biodegradability), a biodegradation test is required. Since biodegradation tests such as BOD/TOC and oxygen uptake would take a long time, we could not know the time to stop ozonation immediately. This study was undertaken to identify process parameters (pH, ORP, ozone concentration in water, ozone gas concentration at the reactor outlet) that could be useful for monitoring and real-time control purposes in ozonation processes. We want to correlate these parameters with biodegradability and intermediates formed in ozonation processes. Results showed that the rapid increase of dissolved ozone and the first plateau termination of off-gas ozone concentrations are good indicators for the depletion of p-nitrophenol, the maximum of biodegradability and the elimination of toxicity. From the mean oxidation state curve, ozonation of p-nitrophenol could be divided into three stages, and a similar pattern could also be observed in ORP profiles. From the results of this research, the application of ozone concentration and ORP profiles as real-time control parameters seems promising.

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44

Boncz, M. A., H. Bruning, W. H. Rulkens, E. J. R. Sudhölter, G. H. Harmsen, and J. W. Bijsterbosch. "Kinetic and mechanistic aspects of the oxidation of chlorophenols by ozone." Water Science and Technology 35, no. 4 (February 1, 1997): 65–72. http://dx.doi.org/10.2166/wst.1997.0087.

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In Advanced oxidation processes (AOPs) radicals are considered to play an important role. Organic contaminations can in AOPs generally be converted to carbon dioxide, water, etc. The most important limitation to the application of AOPs, however, is their high costs, especially when complete mineralisation of the pollutants is pursued. The costs can be reduced by using the oxidant more efficiently, which can be achieved by introducing selectivity. Kinetic and mechanistic data are the basic requirements for optimization of the process. In this work, the influence of several different parameters (temperature, pH, UV irradiation and carbonate concentration) on the kinetics of the degradation ofortho -chlorophenol and para-chlorophenol by ozone was investigated. The pH is the most important parameter. Strongly related to the pH is the degree of ionisation of the phenol, which might be of importance since the shift from a slow to a fast reaction occurs at a higher pH in the case of para-chlorophenol as compared to the case with the more acidic ortho-chlorophenol. A strong indication for a radical mechanism is found in the decrease of the reaction rate in the presence of carbonate, a well known radical scavenger. A further indication is seen in the first step of the reaction, which is dechlorination of the aromatic compound.

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45

Taraborrelli, Domenico, David Cabrera-Perez, Sara Bacer, Sergey Gromov, Jos Lelieveld, Rolf Sander, and Andrea Pozzer. "Influence of aromatics on tropospheric gas-phase composition." Atmospheric Chemistry and Physics 21, no. 4 (February 23, 2021): 2615–36. http://dx.doi.org/10.5194/acp-21-2615-2021.

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Abstract. Aromatics contribute a significant fraction to organic compounds in the troposphere and are mainly emitted by anthropogenic activities and biomass burning. Their oxidation in lab experiments is known to lead to the formation of ozone and aerosol precursors. However, their overall impact on tropospheric composition is uncertain as it depends on transport, multiphase chemistry, and removal processes of the oxidation intermediates. Representation of aromatics in global atmospheric models has been either neglected or highly simplified. Here, we present an assessment of their impact on gas-phase chemistry, using the general circulation model EMAC (ECHAM5/MESSy Atmospheric Chemistry). We employ a comprehensive kinetic model to represent the oxidation of the following monocyclic aromatics: benzene, toluene, xylenes, phenol, styrene, ethylbenzene, trimethylbenzenes, benzaldehyde, and lumped higher aromatics that contain more than nine C atoms. Significant regional changes are identified for several species. For instance, glyoxal increases by 130 % in Europe and 260 % in East Asia, respectively. Large increases in HCHO are also predicted in these regions. In general, the influence of aromatics is particularly evident in areas with high concentrations of NOx, with increases up to 12 % in O3 and 17 % in OH. On a global scale, the estimated net changes of trace gas levels are minor when aromatic compounds are included in our model. For instance, the tropospheric burden of CO increases by about 6 %, while the burdens of OH, O3, and NOx (NO+NO2) decrease between 3 % and 9 %. The global mean changes are small, partially because of compensating effects between high- and low-NOx regions. The largest change is predicted for the important aerosol precursor glyoxal, which increases globally by 36 %. In contrast to other studies, the net change in tropospheric ozone is predicted to be negative, −3 % globally. This change is larger in the Northern Hemisphere where global models usually show positive biases. We find that the reaction with phenoxy radicals is a significant loss for ozone, on the order of 200–300 Tg yr−1, which is similar to the estimated ozone loss due to bromine chemistry. Although the net global impact of aromatics is limited, our results indicate that aromatics can strongly influence tropospheric chemistry on a regional scale, most significantly in East Asia. An analysis of the main model uncertainties related to oxidation and emissions suggests that the impact of aromatics may even be significantly larger.

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46

Gomes, A. C., L. Silva, R. Simões, N. Canto, and A. Albuquerque. "Toxicity reduction and biodegradability enhancement of cork processing wastewaters by ozonation." Water Science and Technology 68, no. 10 (October 22, 2013): 2214–19. http://dx.doi.org/10.2166/wst.2013.478.

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Biodegradability enhancement and detoxification of cork boiling wastewater (CBW) are required for the successful implementation of biological treatment options. We studied the possibility of achieving these goals through ozonation pre-treatment by experimenting on the effect of ozone dose and pH. The CBW used had a pH of 5.81, a chemical oxygen demand (COD) of 1,865 mg L−1, a biochemical oxygen demand (BOD5) of 498 mg L−1 and total phenol (TP) and tannin compounds concentrations of 523 and 399 mg L−1, respectively. The ozone doses ranged from 0.27 to 2.63 for the O3(applied)/COD0 ratios with samples at natural pH and set to 3.33 and 9.96. Ozonation allowed the BOD20/COD ratio (biodegradability index) to increase from 0.37 to 0.63 and a toxicity reduction from 3.08 to 1.24 TU (Microtox). The corresponding removals obtained were 15.2–62.0%, 38.4–83.2% and 56.7–92.1% for COD, TP and colour, respectively. The best outcome of ozonation pre-treatment requires O3(applied)/COD0 ratios over 1.5 and an acid pH. The increase of TP removals with ozone dose at acid pH led to biodegradability enhancement and CBW detoxification. However, for similar conditions the highest COD removals were obtained at alkaline pH due to the hydroxyl radicals’ high oxidation ability but lack of selectivity.

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47

Net, S., L. Nieto-Gligorovski, S. Gligorovski, and H. Wortham. "Heterogeneous ozonation kinetics of 4-phenoxyphenol in presence of photosensitizer." Atmospheric Chemistry and Physics Discussions 9, no. 5 (October 15, 2009): 21647–68. http://dx.doi.org/10.5194/acpd-9-21647-2009.

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Abstract. In this work we have quantitatively measured the degradation of 4-phenoxyphenol adsorbed on silica particles following oxidative processing by gas-phase ozone. This was performed under dark conditions and in presence of 4-carboxybenzophenone under simulated sunlight irradiation of the particles surface. At mixing ratio of 60 ppb which corresponds to strongly ozone polluted areas, the first order decay of 4-phenoxyphenol is k1=9.95×10−6 s−1. At very high ozone mixing ratio of 6 ppm the first order rate constants for 4-phenoxyphenol degradation were the following: k1=2.86×10−5 s−1 under dark conditions and k1=5.58×10−5 s−1 in presence of photosensitizer (4-carboxybenzophenone) under light illumination of the particles surface. In both cases the experimental data do follow the modified Langmuir-Hinshelwood equation for surface reactions. Langmuir-Hinshelwood and Langmuir-Rideal mechanisms are also discussed along with the experimental results. Most importantly, the quantities of the oligomers such as 2-(4-Phenoxyphenoxy)-4-phenoxyphenol and 4-[4-(4-Phenoxyphenoxy)phenoxy]phenol formed during the heterogeneous ozonolysis of adsorbed 4-phenoxyphenol were much higher under solar light irradiation of the surface in comparison to the dark conditions.

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48

Net, S., L. Nieto-Gligorovski, S. Gligorovski, and H. Wortham. "Heterogeneous ozonation kinetics of 4-phenoxyphenol in the presence of photosensitizer." Atmospheric Chemistry and Physics 10, no. 4 (February 15, 2010): 1545–54. http://dx.doi.org/10.5194/acp-10-1545-2010.

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Abstract. In this work we have quantitatively measured the degradation of 4-phenoxyphenol adsorbed on silica particles following oxidative processing by gas-phase ozone. This was performed under dark conditions and in the presence of 4-carboxybenzophenone under simulated sunlight irradiation of the particles surface. At the mixing ratio of 60 ppb which corresponds to strongly polluted ozone areas, the first order of decay of 4-phenoxyphenol is k1=9.95×10−6 s−1. At a very high ozone mixing ratio of 6 ppm the first order rate constants for 4-phenoxyphenol degradation were the following: k1=2.86×10−5 s−1 under dark conditions and k1=5.58×10−5 s−1 in the presence of photosensitizer (4-carboxybenzophenone) under light illumination of the particles surface. In both cases, the experimental data follow the modified Langmuir-Hinshelwood equation for surface reactions. The Langmuir-Hinshelwood and Langmuir-Rideal mechanisms for bimolecular surface reactions are also discussed along with the experimental results. Most importantly, the quantities of the oligomers such as 2-(4-Phenoxyphenoxy)-4-phenoxyphenol and 4-[4-(4-Phenoxyphenoxy)phenoxy]phenol formed during the heterogeneous ozonolysis of adsorbed 4-phenoxyphenol were much higher under solar light irradiation of the surface in comparison to the dark conditions.

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49

Bettazzi, E., M. Morelli, S. Caffaz, C. Caretti, E. Azzari, and C. Lubello. "Olive mill wastewater treatment: an experimental study." Water Science and Technology 54, no. 8 (October 1, 2006): 17–25. http://dx.doi.org/10.2166/wst.2006.781.

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Olive oil production, one of the main agro-industries in Mediterranean countries, generates significant amounts of olive mill wastewaters (OMWs), which represent a serious environmental problem, because of their high organic load, the acidic pH and the presence of recalcitrant and toxic substances such as phenolic and lipidic compounds (up to several grams per litre). In Italy, traditional disposal on the soil is the most common way to discharge OMWs. This work is aimed at investigating the efficiency and feasibility of AOPs and biological processes for OMW treatment. Trials have been carried out on wastewaters taken from one of the largest three-phase mills of Italy, located in Quarrata (Tuscany), as well as on synthetic solutions. Ozone and Fenton's reagents applied both on OMWs and on phenolic synthetic solutions guaranteed polyphenol removal efficiency up to 95%. Aerobic biological treatment was performed in a batch reactor filled with raw OMWs (pH =4.5, T=30 °C) without biomass inoculum. A biomass rich of fungi, developed after about 30 days, was able to biodegrade phenolic compounds reaching a removal efficiency of 70%. Pretreatment of OMWs by means of oxidation increased their biological treatability.

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50

López, Jorge, Ana M. Chávez, Ana Rey, and Pedro M. Álvarez. "Insights into the Stability and Activity of MIL-53(Fe) in Solar Photocatalytic Oxidation Processes in Water." Catalysts 11, no. 4 (March 30, 2021): 448. http://dx.doi.org/10.3390/catal11040448.

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MIL-53(Fe) is a metal organic framework that has been recently considered a heterogeneous photocatalyst candidate for the degradation of water pollutants under visible or solar radiation, though stability studies are rather scarce in the literature. In this work, MIL-53(Fe) was successfully synthesized by a solvothermal method and fully characterized by X-ray diffraction (XRD), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), N2 adsorption–desorption isotherm, Thermogravimetric analysis coupled with mass spectrometry (TGA-MS), UV-visible diffuse reflectance spectroscopy (DRS), elemental analysis and wavelength dispersive X-ray fluorescence (WDXRF). The effects of pH, temperature, solar radiation and the presence of oxidants (i.e., electron acceptors) such as ozone, persulfate and hydrogen peroxide on the stability of MIL-53(Fe) in water were investigated. The as-synthetized MIL-53(Fe) exhibited relatively good stability in water at pH 4 but suffered fast hydrolysis at alkaline conditions. At pH 4–5, temperature, radiation (solar and visible radiation) and oxidants exerted negative effect on the stability of the metal–organic framework (MOF) in water, resulting in non-negligible amounts of metal (iron) and linker (terephthalic acid, H2BDC) leached out from MIL-53(Fe). The photocatalytic activity of MIL-53(Fe) under simulated solar radiation was studied using phenol and metoprolol as target pollutants. MIL-53(Fe) on its own removed less than 10% of the pollutants after 3 h of irradiation, while in the presence of ozone, persulfate or hydrogen peroxide, complete elimination of pollutants was achieved within 2 h of exposure to radiation. However, the presence of oxidants and the formation of some reaction intermediates (e.g., short-chain carboxylic acids) accelerated MIL-53(Fe) decarboxylation. The findings of this work suggest that MIL-53(Fe) should not be recommended as a heterogeneous photocatalyst for water treatment before carrying out a careful evaluation of its stability under actual reaction conditions.

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Journal articles on the topic 'Oxidation. Ozone. Phenols'

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