The Cornwall Water Purification Plant collaborated with the University of Toronto to monitor UV-H2O2 treatment performance. This study includes a review of engineering and operational aspects of UV-H2O2 implementation. A number of operational challenges were experienced with retrofitting UV-H2O2 into the existing treatment plant, and an overview of the challenges and solutions faced at Cornwall is given. The project also includes a thorough water quality analysis. Taste and odour (T&O) events have been monitored for three years and the efficiency of UV-H2O2 on T&O removal is reported. Furthermore, little is known about any potential side effects of the treatment on downstream processes, especially secondary disinfection. The impact of UV-H2O2 on natural organic matter alterations, chlorine stability and disinfection by-product formation is reported using results from full-scale water quality monitoring campaigns at Cornwall, combined with laboratory experiments.

The Cornwall Water Purification Plant collaborated with the University of Toronto to monitor UV-H2O2 treatment performance. This study includes a review of engineering and operational aspects of UV-H2O2 implementation. A number of operational challenges were experienced with retrofitting UV-H2O2 into the existing treatment plant, and an overview of the challenges and solutions faced at Cornwall is given. The project also includes a thorough water quality analysis. Taste and odour (T&O) events have been monitored for three years and the efficiency of UV-H2O2 on T&O removal is reported. Furthermore, little is known about any potential side effects of the treatment on downstream processes, especially secondary disinfection. The impact of UV-H2O2 on natural organic matter alterations, chlorine stability and disinfection by-product formation is reported using results from full-scale water quality monitoring campaigns at Cornwall, combined with laboratory experiments.

Ultraviolet direct photolysis (UV) and the advanced oxidation process UV/H2O2 are new technologies in the water treatment industry. Both treatments can cause the transformation of organic compounds. Nitrosamines and organic chloramines are disinfection by-products (DBPs) formed from the reaction of organic nitrogen compounds during chlorination or chloramination (chlor(am)ination) disinfection. It is therefore possible for UV and UV/H2O2 to affect the organic compound precursors for nitrosamines and organic chloramines and thus their formation from subsequent chlor(am)ination. The precursor compounds, UV and H2O2 doses used for UV or UV/H2O2, and alkalinity were found to have an effect on the formation of nitrosamines and organic chloramines during bench-scale experiments. Full scale studies found UV and UV/H2O2 had different effects on the formation of different nitrosamine species and organic chloramine concentrations, and that a potential correlation existed between the formation of organic chloramines from chlorination and the formation of N-nitrosodimethylamine from chloramination.

Ultraviolet direct photolysis (UV) and the advanced oxidation process UV/H2O2 are new technologies in the water treatment industry. Both treatments can cause the transformation of organic compounds. Nitrosamines and organic chloramines are disinfection by-products (DBPs) formed from the reaction of organic nitrogen compounds during chlorination or chloramination (chlor(am)ination) disinfection. It is therefore possible for UV and UV/H2O2 to affect the organic compound precursors for nitrosamines and organic chloramines and thus their formation from subsequent chlor(am)ination. The precursor compounds, UV and H2O2 doses used for UV or UV/H2O2, and alkalinity were found to have an effect on the formation of nitrosamines and organic chloramines during bench-scale experiments. Full scale studies found UV and UV/H2O2 had different effects on the formation of different nitrosamine species and organic chloramine concentrations, and that a potential correlation existed between the formation of organic chloramines from chlorination and the formation of N-nitrosodimethylamine from chloramination.

Biological and physical chemistry treatment methods always are used to remove COD of organic wastewater contains PCB. The effect is not obvious when the compositions of pollutant are too refractory or complicated. The primary treatment method of wastewater containing copper is chemical coagulation/sedimentation and its disadvantage is producing a large of sludge. The objective of this study, using two combinative method of UV/H2O2-Ferrite Process and Fenton-Ferrite Process, is to remove organic compounds and heavy metal in real wastewater. Not only supernatant liquid could meet the standard of discharge wastewater but also produce general(non-hazardous) industrial wastes of heavy metal. The primary operation condition of Fenton and UV/H2O2 process, was ferrous ion and hydrogen peroxide concentration, pH, reaction time, and chemical dosing, searching best operation condition to combine with Ferrite Process. Operation of Fenton and UV/H2O2 process under acid condition (pH=2) and neutral condition (pH=8) showed the best operation condition of Fenton and UV/H2O2. The removal decreased when the dose of hydrogen peroxide was added too more or too less. As Fenton and UV/H2O2 process test finished, Ferrite Process is next used for treatment of heavy metal wastewater; Ferrite Process conducted as three stages and the operation conditions were controlled with temperature, pH and the ratio of Fe/M mole. The results showed that the best removal of treatment of copper containing wastewater by Ferrite Process achieved when the ratio of Fe/M mole was at 10. Treatment of PCB industrial real wastewater by Fenton-Ferrite Process and UV/H2O2-Ferrite Process which combined with Fenton, UV/H2O2 and Ferrite Process. The supernatant liquid containing organic compounds and heavy metal both could meet the standards of discharge wastewater and the sludge was judged with general(non-hazardous) wastes. The characteristic of the sludge were the diameter lattice less 100 nm and with magnetism and to develop recovery and utilization in a further work.

This study was to investigate the treatment of paraquat-containing solutions by advanced oxidation processes (denoted by AOPs). The operation parameters conducted in semi-batch reactor were as follows: the effect of ozone dose, pH and H2O2 concentration on conversion of paraquat by adding O3, UV, O3/H2O2, UV/H2O2 and UV/O3/H2O2. Paraquat concentration: 10 ppm and 20 ppm, ozone dose: 45 g/hr and 105 g/hr, and H2O2 concentration: 0,07 g/l, 0.71 g/l and 1.127 g/l were tested. In the first stage of pre-test, the purpose was to observe the decomposition of paraquat under various pH in order to compare the conversions by O3 and by O2, and to select the optimal pH in above AOPs. The performances of AOPs for treating paraquat-containing solutions were found in sequence as follows: O3/H2O2, O3, UV/O3, UV/H2O2/O3, UV/H2O2 and UV. The process of O3/H2O2 not only could remove higher concentration of paraquat but also had to need a shorter residence time. The effect of parameters on the removal of paraquat by each AOPs were discussed. The kinetics of AOPs in treatment of paraquat-containing solutions was confirmed by using half-life test. Except UV and UV/H2O2 processes nearing zero order, the apparent reaction order of O3, UV/O3, UV/O3/H2O2 and O3/H2O2 were obtained to be one. Based on the removal and cost analysis, O3/H2O2 (O3 = 45 g/hr, H2O2 dose = 0.71 g/l) was the best process in treating paraquat solutions for the low energy and economic cost. As for the O3 and UV/O3 processes, we also recommended to be yours truly options.

Os efluentes corados ainda são um problema em estações de tratamento de esgoto. Os corantes normalmente apresentam estruturas complexas e difíceis de serem degradadas por processos convencionais, entrando no meio ambiente aquático e causando impacto visual, mudanças nas características físico-químicas da água, prejudicam a fotossíntese do meio e podem apresentar efeitos ecotóxicos. Para o tratamento de vários tipos de efluentes, os Processos Oxidativos Avançados (POAs) são eficientes, rápidos e promovem uma oxidação não seletiva. Os POAs podem se tornar mais eficazes com o acoplamento de outras tecnologias, como as micro-ondas. As micro-ondas não possuem energia suficiente para quebrar as ligações intermoleculares, mas quando somadas ao processo UV/H2O2 pode haver um efeito sinérgico melhorando o desempenho do POA. Neste trabalho, buscou-se a otimização do processo UV/H2O2 acoplado às micro-ondas utilizando-se uma lâmpada de descarga sem eletrodo (LDE) de Hg e Fe. Utilizou-se um planejamento experimental para estudar a degradação de uma mistura de três corantes ácidos de classes diferentes: Acid Blue 9 (C.I. 42090, triarilmetano), Acid Red 92 (C.I. 45410, xanteno) e Acid Yellow 23 (C.I. 19140, monoazo). A variável-resposta observada foi a concentração residual dos corantes medida por CLAE. As condições ótimas para o tratamento foram: concentração inicial de peróxido de hidrogênio = 125 mg L-1, pH= 6,2 e vazão = 800 mL min-1. Em 180 min de tratamento, correspondente a 45 min de irradiação alcançou-se uma degradação de 23, 20 e 98% para AB9, AR92 e AY23 respectivamente. O modelo cinético foi de pseudo 1ª ordem para o AY23, com k = (1,7 ±0,041) × 10-2 min-1 e R² = 0,990. Não foi possível determinar a cinética de degradação do AB9 e do AR92 por causa da baixa degradação alcançada (aproximadamente uma ordem de grandeza menor). A partir das análises de espectrometria de massas, observou-se um único produto de degradação: o AY23 monohidroxilado. Esse produto não apresentou ecotoxicidade para o organismo-teste L. sativa. No entanto, ele foi tóxico para o organismo D. similis, imobilizando os microcrustáceos em todas as diluições testadas. / Colored effluents are still a problem in wastewater treatment plants. Dyes usually have complex structures that are difficult to be degraded by conventional processes, thus entering into the aquatic environment and causing visual impact, changes in the water physicochemical characteristics, impairing photosynthesis, and posing ecotoxic effects. For the treatment of various types of wastewater, the Advanced Oxidation Processes (AOP) are efficient, fast and promote non-selective oxidation. AOPs can become more effective by coupling them to other technologies, such as microwaves. Microwaves do not have enough energy to break intermolecular bonds, but when coupled to the UV/H2O2 process, there may be a synergistic effect improving the AOP performance. In this study, the UV/H2O2 process coupled to microwaves, using an Hg and Fe electrodeless discharge lamp (EDL), was optimized. An experimental design was performed to study the degradation of a mixture of three acid dyes of different classes: Acid Blue 9 (C.I. 42090 , triarylmethane), Acid Red 92 (C.I. 45410, xanthene), and Acid Yellow 23 (C.I. 19140, monoazo). The observed response variable was the residual concentration of the dyes measured by HPLC. The optimum conditions for the treatment were: initial hydrogen peroxide concentration = 125 mg L- 1, pH = 6.2, and flow rate = 800 mL min-1. In 180 min of treatment, corresponding to 45 min of irradiation, it was achieved a degradation of 23, 20, and 98% for AB9, AR92, and AY23 respectively. The AY23 degradation followed a pseudo-first-order kinetic model, with k = (1.7 ±0,041) × 10-2 min-1 and R² = 0.990. It was not possible to determine the degradation kinetics of AB9 and AR92 due to the low degradation achieved (approximately one order of magnitude lower). From mass espectrometry analyses, only one degradation product was observed: monohydroxilated AY23. That product showed no ecotoxicity towards the test-organism L. sativa. However, it was toxic towards the test-organism D. similis, immobilizing the microcrustaceans in all tested dilutions.

Os efluentes corados ainda são um problema em estações de tratamento de esgoto. Os corantes normalmente apresentam estruturas complexas e difíceis de serem degradadas por processos convencionais, entrando no meio ambiente aquático e causando impacto visual, mudanças nas características físico-químicas da água, prejudicam a fotossíntese do meio e podem apresentar efeitos ecotóxicos. Para o tratamento de vários tipos de efluentes, os Processos Oxidativos Avançados (POAs) são eficientes, rápidos e promovem uma oxidação não seletiva. Os POAs podem se tornar mais eficazes com o acoplamento de outras tecnologias, como as micro-ondas. As micro-ondas não possuem energia suficiente para quebrar as ligações intermoleculares, mas quando somadas ao processo UV/H2O2 pode haver um efeito sinérgico melhorando o desempenho do POA. Neste trabalho, buscou-se a otimização do processo UV/H2O2 acoplado às micro-ondas utilizando-se uma lâmpada de descarga sem eletrodo (LDE) de Hg e Fe. Utilizou-se um planejamento experimental para estudar a degradação de uma mistura de três corantes ácidos de classes diferentes: Acid Blue 9 (C.I. 42090, triarilmetano), Acid Red 92 (C.I. 45410, xanteno) e Acid Yellow 23 (C.I. 19140, monoazo). A variável-resposta observada foi a concentração residual dos corantes medida por CLAE. As condições ótimas para o tratamento foram: concentração inicial de peróxido de hidrogênio = 125 mg L-1, pH= 6,2 e vazão = 800 mL min-1. Em 180 min de tratamento, correspondente a 45 min de irradiação alcançou-se uma degradação de 23, 20 e 98% para AB9, AR92 e AY23 respectivamente. O modelo cinético foi de pseudo 1ª ordem para o AY23, com k = (1,7 ±0,041) × 10-2 min-1 e R² = 0,990. Não foi possível determinar a cinética de degradação do AB9 e do AR92 por causa da baixa degradação alcançada (aproximadamente uma ordem de grandeza menor). A partir das análises de espectrometria de massas, observou-se um único produto de degradação: o AY23 monohidroxilado. Esse produto não apresentou ecotoxicidade para o organismo-teste L. sativa. No entanto, ele foi tóxico para o organismo D. similis, imobilizando os microcrustáceos em todas as diluições testadas. / Colored effluents are still a problem in wastewater treatment plants. Dyes usually have complex structures that are difficult to be degraded by conventional processes, thus entering into the aquatic environment and causing visual impact, changes in the water physicochemical characteristics, impairing photosynthesis, and posing ecotoxic effects. For the treatment of various types of wastewater, the Advanced Oxidation Processes (AOP) are efficient, fast and promote non-selective oxidation. AOPs can become more effective by coupling them to other technologies, such as microwaves. Microwaves do not have enough energy to break intermolecular bonds, but when coupled to the UV/H2O2 process, there may be a synergistic effect improving the AOP performance. In this study, the UV/H2O2 process coupled to microwaves, using an Hg and Fe electrodeless discharge lamp (EDL), was optimized. An experimental design was performed to study the degradation of a mixture of three acid dyes of different classes: Acid Blue 9 (C.I. 42090 , triarylmethane), Acid Red 92 (C.I. 45410, xanthene), and Acid Yellow 23 (C.I. 19140, monoazo). The observed response variable was the residual concentration of the dyes measured by HPLC. The optimum conditions for the treatment were: initial hydrogen peroxide concentration = 125 mg L- 1, pH = 6.2, and flow rate = 800 mL min-1. In 180 min of treatment, corresponding to 45 min of irradiation, it was achieved a degradation of 23, 20, and 98% for AB9, AR92, and AY23 respectively. The AY23 degradation followed a pseudo-first-order kinetic model, with k = (1.7 ±0,041) × 10-2 min-1 and R² = 0.990. It was not possible to determine the degradation kinetics of AB9 and AR92 due to the low degradation achieved (approximately one order of magnitude lower). From mass espectrometry analyses, only one degradation product was observed: monohydroxilated AY23. That product showed no ecotoxicity towards the test-organism L. sativa. However, it was toxic towards the test-organism D. similis, immobilizing the microcrustaceans in all tested dilutions.

Os processos oxidativos avançados são promissores para a degradação de compostos orgânicos resistentes aos tratamentos convencionais, como o fenol. A fluidodinâmica computacional (CFD) tornou-se uma poderosa ferramenta para analisar processos fotoquímicos por resolver os balanços acoplados de quantidade de movimento, de massa e de radiação. O objetivo deste trabalho é investigar o processo UV/H2O2 num reator fotoquímico anular usando CFD e um modelo cinético mais realista. O modelo em CFD foi criado de forma progressiva. Inicialmente, foram determinados os campos de velocidade para três vazões (30, 60 e 100 L/h). Considerou-se dois diâmetros de lâmpada para reproduzir a configuração experimental do sistema. A discretização foi feita com malhas tetraédricas variando entre 390 000 e 1 200 000 elementos. Quatro modelos de turbulência RANS foram analisados: k-e, k-w, o shear stress transport (SST) e o modelo de tensões de Reynolds (RSM). O campo de velocidades foi validado comparando a DTR com seu levantamento experimental. A próxima etapa foi incluir o mecanismo de degradação de fenol proposto por Edalatmanesh, Dhib e Mehrvar (2008) no modelo em CFD. Trata-se de um modelo cinético baseado em equações dinâmicas para todas as espécies. O campo de radiação foi calculado pelo modelo radial e pela solução da equação de transporte de radiação através do método discrete transfer. As simulações reproduziram dados experimentais abrangendo uma larga gama de concentrações iniciais de fenol, razões molares H2O2/fenol e três potências de emissão das lâmpadas. O campo de velocidades obtido era dependente da vazão: o fluido pode manter movimento helicoidal sobre toda a extensão do reator ou se desenvolver como um escoamento pistonado. O modelo k-e não reproduziu bem o escoamento por não ser adequado para escoamentos rotativos. Os outros modelos geraram curvas de DTR com bom ajuste aos dados experimentais, especialmente o modelo k-w. O desvio médio entre as simulações de degradação de fenol e os dados experimentais é inferior a 8%. Verificou-se que, devido ao escoamento rotativo, os reagentes ficavam concentrados próximos à parede externa e migravam para a região da lâmpada ao longo do reator. A elevada intensidade de radiação na superfície da lâmpada criou uma camada ao seu redor na qual a fotólise do H2O2 ocorreu com grande taxa. Os radicais OH gerados nessa camada eram transportados para a região das paredes por convecção. Isso fez com que a maior parte do fenol fosse atacada na segunda metade do reator e gerou acúmulo do radical próximo à lâmpada na seção de saída do reator, já que o poluente já fora oxidado nessa área. O método discrete transfer previu intensidades de radiação maiores que o modelo radial, e, consequentemente, maior concentração de radicais OH. Os resultados satisfatórios indicam que CFD foi uma ferramenta adequada para analisar este escoamento reativo. / Advanced oxidation processes are a promising technology for degradation of organic compounds resistant to conventional treatments such as phenol. Computational fluid dynamics (CFD) has recently emerged as a powerful tool that allows a deeper understanding of photochemical processes in reactor engineering by solving the coupled momentum, mass and radiation balances. This work aimed to investigate the UV/H2O2 process in an annular photoreactor using CFD and a more realistic kinetic model. A progressive approach was used to develop the CFD reactor model. First, the velocity fields were determined for three volumetric flow rates (30, 60 and 100 L/h). Two lamp diameters were considered to reflect the experimental configuration of the system. Tetrahedral meshes varying form 390,000 to 1,200,000 elements were analyzed to achieve grid independence. For accounting turbulence effects, four RANS models were tested: k-e, k-w, the Shear Stress Transport (SST) and the Reynolds Stress models (RSM). The velocity field was validated through comparison to RTD experimental data. Next step was introducing the mechanism of phenol degradation proposed by Edalatmanesh, Dhib and Mehrvar (2008) into the CFD model. This kinetic model is based on dynamic equations for all species. The fluence rate field was calculated by the radial model and by solving the radiation transport equation with the discrete transfer method. Simulations reproduced experimental data spanning a wide range of initial phenol concentrations, H2O2/phenol molar ratios and three values for lamp power. It was found that the velocity field depends on the volumetric flow rate: either it maintains a swirling motion through the whole reactor or might develop like a plug flow. The k-e model did not represent the RTD data accurately, and the velocity field therefore, since it is not appropriate for swirling flows. The other turbulence models showed good match of RTD, especially the k-w model. Simulations of phenol degradation deviated less than 8% from experimental data. It was possible verified that, due to the swirling inlet effects, reactants got concentrated close to the outer wall and migrated on the lamp direction along the reactor path. High radiation intensities close to the lamp surface created a layer around it where photolysis of H2O2 took place with higher rates. OH radicals were generated in that layer and transported towards the outer wall by convection. This caused most of phenol to be consumed in the second half of the reactor and accumulation of the radical near the lamp and the reactor outlet, since the pollutant in this area was already oxidized. The discrete transfer method predicted higher incident radiation intensity than the radial model, and higher concentrations of OH radicals as a consequence. Satisfactory results indicated that CFD was an appropriate tool for analyzing this reactive flow.

Os processos oxidativos avançados são promissores para a degradação de compostos orgânicos resistentes aos tratamentos convencionais, como o fenol. A fluidodinâmica computacional (CFD) tornou-se uma poderosa ferramenta para analisar processos fotoquímicos por resolver os balanços acoplados de quantidade de movimento, de massa e de radiação. O objetivo deste trabalho é investigar o processo UV/H2O2 num reator fotoquímico anular usando CFD e um modelo cinético mais realista. O modelo em CFD foi criado de forma progressiva. Inicialmente, foram determinados os campos de velocidade para três vazões (30, 60 e 100 L/h). Considerou-se dois diâmetros de lâmpada para reproduzir a configuração experimental do sistema. A discretização foi feita com malhas tetraédricas variando entre 390 000 e 1 200 000 elementos. Quatro modelos de turbulência RANS foram analisados: k-e, k-w, o shear stress transport (SST) e o modelo de tensões de Reynolds (RSM). O campo de velocidades foi validado comparando a DTR com seu levantamento experimental. A próxima etapa foi incluir o mecanismo de degradação de fenol proposto por Edalatmanesh, Dhib e Mehrvar (2008) no modelo em CFD. Trata-se de um modelo cinético baseado em equações dinâmicas para todas as espécies. O campo de radiação foi calculado pelo modelo radial e pela solução da equação de transporte de radiação através do método discrete transfer. As simulações reproduziram dados experimentais abrangendo uma larga gama de concentrações iniciais de fenol, razões molares H2O2/fenol e três potências de emissão das lâmpadas. O campo de velocidades obtido era dependente da vazão: o fluido pode manter movimento helicoidal sobre toda a extensão do reator ou se desenvolver como um escoamento pistonado. O modelo k-e não reproduziu bem o escoamento por não ser adequado para escoamentos rotativos. Os outros modelos geraram curvas de DTR com bom ajuste aos dados experimentais, especialmente o modelo k-w. O desvio médio entre as simulações de degradação de fenol e os dados experimentais é inferior a 8%. Verificou-se que, devido ao escoamento rotativo, os reagentes ficavam concentrados próximos à parede externa e migravam para a região da lâmpada ao longo do reator. A elevada intensidade de radiação na superfície da lâmpada criou uma camada ao seu redor na qual a fotólise do H2O2 ocorreu com grande taxa. Os radicais OH gerados nessa camada eram transportados para a região das paredes por convecção. Isso fez com que a maior parte do fenol fosse atacada na segunda metade do reator e gerou acúmulo do radical próximo à lâmpada na seção de saída do reator, já que o poluente já fora oxidado nessa área. O método discrete transfer previu intensidades de radiação maiores que o modelo radial, e, consequentemente, maior concentração de radicais OH. Os resultados satisfatórios indicam que CFD foi uma ferramenta adequada para analisar este escoamento reativo. / Advanced oxidation processes are a promising technology for degradation of organic compounds resistant to conventional treatments such as phenol. Computational fluid dynamics (CFD) has recently emerged as a powerful tool that allows a deeper understanding of photochemical processes in reactor engineering by solving the coupled momentum, mass and radiation balances. This work aimed to investigate the UV/H2O2 process in an annular photoreactor using CFD and a more realistic kinetic model. A progressive approach was used to develop the CFD reactor model. First, the velocity fields were determined for three volumetric flow rates (30, 60 and 100 L/h). Two lamp diameters were considered to reflect the experimental configuration of the system. Tetrahedral meshes varying form 390,000 to 1,200,000 elements were analyzed to achieve grid independence. For accounting turbulence effects, four RANS models were tested: k-e, k-w, the Shear Stress Transport (SST) and the Reynolds Stress models (RSM). The velocity field was validated through comparison to RTD experimental data. Next step was introducing the mechanism of phenol degradation proposed by Edalatmanesh, Dhib and Mehrvar (2008) into the CFD model. This kinetic model is based on dynamic equations for all species. The fluence rate field was calculated by the radial model and by solving the radiation transport equation with the discrete transfer method. Simulations reproduced experimental data spanning a wide range of initial phenol concentrations, H2O2/phenol molar ratios and three values for lamp power. It was found that the velocity field depends on the volumetric flow rate: either it maintains a swirling motion through the whole reactor or might develop like a plug flow. The k-e model did not represent the RTD data accurately, and the velocity field therefore, since it is not appropriate for swirling flows. The other turbulence models showed good match of RTD, especially the k-w model. Simulations of phenol degradation deviated less than 8% from experimental data. It was possible verified that, due to the swirling inlet effects, reactants got concentrated close to the outer wall and migrated on the lamp direction along the reactor path. High radiation intensities close to the lamp surface created a layer around it where photolysis of H2O2 took place with higher rates. OH radicals were generated in that layer and transported towards the outer wall by convection. This caused most of phenol to be consumed in the second half of the reactor and accumulation of the radical near the lamp and the reactor outlet, since the pollutant in this area was already oxidized. The discrete transfer method predicted higher incident radiation intensity than the radial model, and higher concentrations of OH radicals as a consequence. Satisfactory results indicated that CFD was an appropriate tool for analyzing this reactive flow.