Oxidation of Phenol by Persulfate Activated with UV-Light and Ag+

2012 ◽  
Vol 610-613 ◽  
pp. 1806-1809
Author(s):  
De Dong Sun ◽  
Huan Zheng ◽  
Wen Ping Xue
Keyword(s):  
Uv Irradiation ◽  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Uv Light ◽  
Irradiation Time ◽  
Phenol Degradation ◽  
Oxygen Demand ◽  
Mercury Vapor ◽  
Cod Reduction

Phenol degradation with a UV/Ag+/K2S2O8 advanced oxidation process (AOP) was studied in a batch photolytic reactor. The UV irradiation source was a low-pressure mercury vapor lamp that was axially centered and was immersed in the phenol solution. In the UV/ K2S2O8 and Ag+/K2S2O8 system, the degradation of phenol was inefficient with an low concentration K2S2O8 at ambient temperature, and only around 26% and 23%of the phenol was degraded in 3 h , respectively. In the UV/Ag+/K2S2O8 oxidation process, persulfate (S2O82-) was activated by UV irradiation and Ag+ catalysis to produce powerful oxidants, SO4– •.The effects of K2S2O8 concentration, UV irradiation time and Ag+ concentration on the oxidation had been investigated. The experimental results indicated that optimum K2S2O8 concentration was 0.37mmol/L, and Ag+ concentration was 0.185 mmol/L. Phenol and chemical oxygen demand (COD) reduction was analyzed to determine the efficiency of the UV/Ag+/K2S2O8 process in mineralization, where we obtained 77% phenol reduction, and 65% COD reduction, respectively . The efficient mineralization of phenol is based on the in situ formation of the strong oxidant sulfate anion radical.

UV Based Advanced Oxidation Process for Degradation of Ciprofloxacin: Reaction Kinetics, Effects of Interfering Substances and Degradation Product Identification

2021 ◽  
Author(s):  
Bijoli Mondal ◽  
Shib Sankar Basak ◽  
Arnab Das ◽  
Sananda Sarkar ◽  
Asok Adak
Keyword(s):  
Organic Compounds ◽  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Uv Light ◽  
Degradation Products ◽  
Irradiation Time ◽  
Advanced Oxidation ◽  
Quantum Yields ◽  
Photon Flux ◽  
First Order

Abstract In the photochemical UV-H2O2 advanced oxidation process, H2O2 absorbs UV light and is decomposed to form hydroxyl radicals (OH·), which are highly excited and reactive for electron-rich organic compounds and hence can degrade organic compounds. In the present work, the UV-H2O2 process was investigated to degrade ciprofloxacin (CIP), one of India's widely used antibiotics, from aqueous solutions using a batch type UV reactor having photon flux = 1.9 (± 0.1) ×10-4 Einstein L-1 min-1. The effects of UV irradiation time on CIP degradation were investigated for both UV and UV-H2O2 processes. It was found that about 75% degradation of CIP was achieved within 60 s with initial CIP concentration and peroxide concentration of 10 mg L-1 and 1 mol H2O2/ mol CIP, respectively, at pH of 7(±0.1) and fluence dose of 113 mJ cm-2. The experimental data were analyzed by the first-order kinetics model to find out the time- and fluence-based degradation rate constants. Under optimized experimental conditions (initial CIP concentration, pH and H2O2 dose of 10 mg L-1, 7(±0.1) and 1.0 mol H2O2 / mol CIP, respectively), the fluence-based pseudo-first-order rate constant for the UV and UV-H2O2 processes were determined to be 1.28(±0.0) ×10-4 and 1.20(±0.04) ×10-2 cm2 mJ-1 respectively. The quantum yields at various pH under direct UV were calculated. The impacts of different process parameters such as H2O2 concentration, solution pH, initial CIP concentration, and wastewater matrix on CIP degradation were also investigated in detail. CIP degradation was favorable in acidic conditions. Six degradation products of CIP were identified. Results clearly showed the potentiality of the UV-H2O2 process for the degradation of antibiotics in wastewater.

Aging Behavior of the Polyether Polyurethane Films Irradiated by UV

2013 ◽  
Vol 748 ◽  
pp. 16-21 ◽  
Author(s):  
Hai Yan Wang ◽  
Yu Wen Liu ◽  
Bin Sun ◽  
Shi Jie Huang ◽  
Ji Feng Tian
Keyword(s):  
Aromatic Ring ◽  
Uv Irradiation ◽  
Uv Light ◽  
Irradiation Time ◽  
Color Difference ◽  
Molecular Structures ◽  
Hydroxyl Group ◽  
Failure Behavior ◽  
Polyurethane Film

The failure behavior of polyether polyurethane films irradiated by UV depends on its molecular structures evolvement. The molecular structure evolvement of the polyether polyurethane films under UV irradiation were studied by in-situ FTIR spectra in this paper. It has been found that some oxygen contained groups such as hydroxyl group and carbonyl group increase; on the contrary, ether bond and CH2 decrease with the UV irradiation time. The aromatic ring maintains changeless. However, -NH group has not be determined due to the interference of the-OH and O-C=O. Results from FTIR and SEM have shown that UV photodegradative processes participated by oxidization occur mostly in ether segments and is accompanied by crosslinkage. Using the absorbance band of aromatic ring as the base the service life of polyether polyurethane can be determined by the change rate of C-O-C and-CH2 during UV irradiation. After UV irradiation, the polyether polyurethane film has higher color difference value and lower UV light transparence.

scholarly journals One-step Oxidation of Total Organic Carbon, Total Nitrogen, and Total Phosphorous using Wet Chemical Oxidation

2020 ◽  
Vol 42 (12) ◽  
pp. 603-609
Author(s):  
Jeong-Hwan Choi ◽  
Dong-Hun Shin ◽  
Hye-Bin Kim ◽  
Jong-Gook Kim ◽  
Kitae Baek
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Total Nitrogen ◽  
Uv Irradiation ◽  
Oxidation Process ◽  
Irradiation Time ◽  
Suitable Condition ◽  
Chemical Oxidation ◽  
Total Phosphorous ◽  
Wet Chemical

Objective:This study proposed the simultaneous multi-oxidation of total organic carbon, total nitrogen, and total phosphorous using modified wet chemical oxidation method.Methods:The multi oxidation process was based on the dual radical system with sulfate and hydroxyl radicals. The sodium persulfate (Na2S2O8) and sodium hydroxide (NaOH) were activated at 40℃ and UV irradiation with 254 nm to generate the sulfate radical and hydroxyl radical. The organic matters were oxidized by the dual radicals, and TOC, TN, and TP values were compared with the control group.Results and Discussion:The dual radical system oxidized organic carbon to carbon dioxide effectively, and the TOC values were similar to the value obtained from the high-temperature combustion technique. However, the residual persulfate after oxidation process interfered the absorbance for TN and inhibit the complexation in TP measurement. The residual persulfate was effectively converted to sulfate by longer heating and UV irradiation, and the interferences were more sensitive to reaction temperature than UV irradiation time. As a result, a higher temperature condition was more effective and enhanced the applicability of multi-oxidation.Conclusions:The multi oxidation of TOC, TN, and TP was demonstrated by wet chemical oxidation, and the proposed method is expected to secure the sample and reduce the analytic time. However, the more suitable condition to enhance the accuracy of TOC, TN, and TP in the multi-oxidation system should be studied further.

Humic acid removal by gas–liquid interface discharge plasma: performance, mechanism and comparison to ozonation

2019 ◽  
Vol 5 (1) ◽  
pp. 152-160 ◽  
Author(s):  
Yanyan Cui ◽  
Jianwei Yu ◽  
Ming Su ◽  
Zeyu Jia ◽  
Tingting Liu ◽  
...  
Keyword(s):  
Humic Acid ◽  
Advanced Oxidation Process ◽  
Discharge Plasma ◽  
Oxidation Process ◽  
Advanced Oxidation ◽  
Liquid Interface ◽  
Oh Radicals ◽  
Discharge Process

A novel advanced oxidation process (AOP) based on plasma in gas–liquid interface discharge was evaluated for humic acid removal. Much better performance was obtained compared to ozonation. The OH˙ radicals generated by reaction of in situ produced ozone and H2O2 during discharge process were mainly responsible for the removal.

Synthesis, characterization, and application of polyanisidines as efficient photostabilizers for poly(vinyl chloride) films

2019 ◽  
Vol 52 (6) ◽  
pp. 537-547
Author(s):  
Magdy W. Sabaa ◽  
Mohamed A Sanad ◽  
Mahmoud A Abd El-Ghaffar ◽  
Nourelhoda A Abdelwahab ◽  
Soha MA Sayed ◽  
...  
Keyword(s):  
Vinyl Chloride ◽  
Uv Irradiation ◽  
Oxidation Process ◽  
Irradiation Time ◽  
Chemical Oxidation ◽  
Polymeric Chain ◽  
Conductivity Measurements ◽  
Uv Absorber ◽  
Poly Vinyl Chloride ◽  
Pvc Film

Conducting polymers have great attention due to their electrical activity in π-electrons conjugation over backbone of the polymeric chain. These properties make them attractive for enormous applications. On that account, we prepared polyanisidines (PAs) derivatives ( ortho, meta, and para) by chemical oxidation process using ammonium peroxydisulfate as an initiator. The prepared PAs were characterized using various techniques. Moreover, conductivity measurements of PA derivatives showed that the ortho-derivative gave the highest value. The prepared PAs were investigated as photostabilizers for poly(vinyl chloride) (PVC) films. Different PVC films were prepared in the absence and the presence of PA derivatives and they were exposed to ultraviolet (UV) irradiation for 30 days. The gel weight % for irradiated PVC films was followed as a function of irradiation time. The results revealed that the blank PVC film (free PA derivatives) was completely degraded reaching 100% gel content. PVC films contain PA derivatives showed higher photostability than PVC blank film. A comparison between the investigated PA derivatives as UV stabilizers and Chimassorb commercial UV absorber was also investigated. PA derivatives showed better efficiency as UV stabilizers than the commercial one till 288 h of UV irradiation.

Degradation of PVDF-based composite membrane and its impacts on membrane intrinsic and separation properties

2016 ◽  
Vol 36 (3) ◽  
pp. 261-268 ◽  
Author(s):  
Mei Jiun Lee ◽  
Chi Siang Ong ◽  
Woei Jye Lau ◽  
Be Cheer Ng ◽  
Ahmad Fauzi Ismail ◽  
...  
Keyword(s):  
Uv Irradiation ◽  
Exposure Time ◽  
Composite Membrane ◽  
Polyvinylidene Fluoride ◽  
Uv Light ◽  
Irradiation Time ◽  
Uv Exposure ◽  
Polymeric Membrane ◽  
Permeate Flux ◽  
Wastewater Treatment Process

Abstract In this work, an attempt was made to evaluate the effects of ultraviolet (UV) irradiation period on the intrinsic and separation properties of composite membrane composed of organic polyvinylidene fluoride and inorganic titanium dioxide (TiO2) nanoparticles by exposing the membrane to UV-A light for up to 250 h. The changes on membrane structural morphologies and chemical characteristics upon UV exposure were studied by field-emission scanning electron microscope and Fourier transform infrared, respectively. It was observed that some cracks and fractures were formed on the membrane outer surface when it was exposed to 120-h UV light. Further increase in UV irradiation time to 250 h had caused membrane structure to collapse, turning it into powder form. Filtration experiments showed that the permeate flux of irradiated membrane was significantly increased from 10.89 L/m2 h to 21.84 L/m2 h (>100% flux increment) while oil rejection decreased with increasing UV exposure time from 0 h to 120 h. Furthermore, the mechanical strength and thermal stability of irradiated membrane were also reported to decrease with increasing UV exposure time, suggesting the negative impacts of UV light on the membrane overall stability. This research is of particular importance to evaluate the suitability and sustainability of polymeric membrane, which is widely considered as the host for photocatalyts and used for wastewater treatment process under UV irradiation.

scholarly journals DEGRADAÇÃO DO CORANTE AZUL REATIVO 5G PELO PROCESSO OXIDATIVO AVANÇADO UV/H2O2

e-xacta ◽  
2016 ◽  
Vol 9 (2) ◽  
Author(s):  
Denis Rafael de Souza Lima ◽  
Isabela Luiza Alves de Almeida ◽  
Vanderlei Inácio de Paula
Keyword(s):  
Hydrogen Peroxide ◽  
Ultraviolet Radiation ◽  
Chemical Oxygen Demand ◽  
Lactuca Sativa ◽  
Azo Dye ◽  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Oxygen Demand ◽  
Liquid Wastes ◽  
Optimized Conditions

<p>Neste trabalho avaliou-se a aplicação do processo oxidativo avançado (POA) de foto-peroxidação (UV/H<sub>2</sub>O<sub>2</sub>) na degradação do azocorante têxtil comercial Azul Reativo 5G. Foram preparadas soluções sintéticas contendo o corante e tratadas através do respectivo POA, sendo a eficiência do tratamento avaliada através dos seguintes parâmetros: descoloração, redução da demanda química de oxigênio (DQO) e ecotoxicidade com sementes de Lactuca sativa. Após 30 minutos de tratamento em condições otimizadas na presença de peróxido de hidrogênio e radiação ultravioleta, foi observada descoloração na ordem de 91,8% sem redução significativa da DQO (1,8%), além de diminuição da ecotoxicidade da solução, indicando a viabilidade da aplicação do processo UV/H<sub>2</sub>O<sub>2</sub> para tratamento de resíduos líquidos contendo este azocorante.</p><p>ABSTRACT</p><p>In the present paper was evaluated the application of advanced oxidation process (AOP) photo-peroxidation (UV/H<sub>2</sub>O<sub>2</sub>) applied to degradation of the commercial textile azo dye Reactive Blue 5G. Synthetic solutions were prepared containing the dye, treated through the respective AOP and the efficiency of the treatment evaluated by the following parameters: discoloration, reduction of chemical oxygen demand (COD) and ecotoxicity with Lactuca sativa seeds. After 30 minutes of treatment in optimized conditions in the presence of hydrogen peroxide and ultraviolet radiation, discoloration was observed in order of 91.8% without significant reduction of COD (1.8%), but decrease in the ecotoxicity of the solution, indicating feasibility of the process UV/H<sub>2</sub>O<sub>2</sub> for treating liquid wastes containing this azo dye.</p>

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