펜톤, 펜톤-유사 및 광-펜톤-유사 반응을 이용한 Rhodamine B의 탈색

박영식,김동석 한국환경보건학회 2007 한국환경보건학회지 Vol.33 No.2

The chemical and photochemical decolorization of Rhodamine B (RhB) in water has been carried out by Fenton, Fenton-like and photo-Fenton-like process. The effect of applied H2O2, Fe2+ dosage (Fenton process), H2O2, Feo dosage (Fenton-like and photo-Fenton-like process), UV light power (photo-Fenton-like process) pH (all processes) have been studied. The results obtained showed that more than 98% of color removal was obtained for the RhB solutions in every process. However, Fenton-like process was not suitable for the color removal of RhB because Fenton-like process was required much more reagents than Fenton and photo-Fenton-like process. The Fenton and photo-Fenton-like process showed similar reagents need. Optimum pH for three processes in this study is about pH 3. The relative order of sensitivity for pH of each process was: Fenton-like > photo-Fenton-like > Fenton.

Modified Photo-Fenton Reaction을 이용한 Methyl Tert-butyl Ether (MTBE)의 분해 Kinetic 및 메커니즘 규명에 관한 연구

김민경,공성호,Kim, Min-Kyoung,Kong, Sung-Ho 한국지하수토양환경학회 2006 지하수토양환경 Vol.11 No.6

지하 저장 탱크로부터의 유류 유출로 인하여 전세계적으로 넓은 지역의 토양 및 지하수가 오염되고 있다. Methyl tert-butyl ether(MTBE)는 대기 오염 감소를 위하여 널리 사용되고 있는 유류 첨가제이지만 토양 및 지하수로 유입되어 섭취 되었을 때 발암 가능성이 있는 유독 물질이다. 본 연구는 고도 산화 처리 기법 중 유기 오염물의 분해에 높은 효율을 나타내는 고전적 Fenton reaction의 최대 단점인 강한 산성(pH 2.5-3) 의존성을 극복한 새로운 산화 처리 기법을 개발하여 고농도의 MTBE를 효과적으로 분해 하는 것을 그 목적으로 하여 자연 친화적인 chelating agents를 사용하여 중성 영역에서 Fenton reaction을 가능하게 하는 기법인 Modified Fenton reaction과 Ultra Violet light(UV)를 이용하여 분해효율을 극대화 하는 Photo-assisted Fenton reaction을 응용한 Modified Photo-Fenton reaction system을 개발하여 최적 반응 조건 및 반응 차수, 반응 메커니즘을 밝혀내었다. 낮은 독성과 높은 생분해성을 나타낸 Citrate ion을 chelating agents로 선정하였으며 최적 반응 조건은 [$Fe^{3+}$] : [Citrate] = 1 mM : 4 mM, 3% $H_2O_2$, 17.4 kWh/L UV dose, 초기 pH 6.0이며 이 조건에서 1000 ppm MTBE를 분해한 결과 6시간 후 86.75%, 16시간 후 99.99%의 높은 분해율을 나타냈으며 최종 pH는 6.02로 안정적이었다. 또한 Modified Photo-Fenton reaction을 이용한 MTBE 분해 반응은 유사 1차 반응을 나타내었으며 methoxy group이 ${\cdot}OH$ radical과 주로 반응하여 tert-butyl formate(TBF)가 주요 분해 산물이 되는 분해 경로를 따른 다는 것이 밝혀졌다. 본 연구로 개발된 Modified Photo-Fenton reaction에서 발생되는 산화제인 ${\cdot}OH$ radical의 비선택적 반응성을 고려할 때 본 system은 다른 종류의 유기 오염물 분해에도 효과적일 것으로 판단된다. Improper disposal of petroleum and spills from underground storage tanks have created large areas with highly toxic contamination of the soil and groundwater. Methyl tert-butyl ether (MTBE) is widely used as a fuel additive because of its advantageous properties of increasing the octane value and reducing carbon monoxide and hydrocarbon exhausts. However, MTBE is categorized as a possible human carcinogen. This research investigated the Modified Photo-Fenton system which is based on the Modified Fenton reaction and UV light irradiation. The Modified Fenton reaction is effective for MTBE degradation near a neutral pH, using the ferric ion complex composed of a ferric ion and environmentally friendly organic chelating agents. This research was intended to treat high concentrations of MTBE; thus, 1,000 mg/L MTBE was chosen. The objectives of this research are to find the optimal reaction conditions and to elucidate the kinetic and mechanism of MTBE degradation by the Modified Photo-Fenton reaction. Based on the results of experiments, citrate was chosen among eight chelating agents as the candidate for the Modified Photo-Fenton reaction because it has a relatively higher final pH and MTBE removal efficiency than the others, and it has a relatively low toxicity and is rapidly biodegradable. MTBE degradation was found to follow pseudo-first-order kinetics. Under the optimum conditions, [$Fe^{3+}$] : [Citrate] = 1 mM: 4 mM, 3% $H_2O_2$, 17.4 kWh/L UV dose, and initial pH 6.0, the 1000 ppm MTBE was degraded by 86.75% within 6 hours and 99.99% within 16 hours. The final pH value was 6.02. The degradation mechanism of MTBE by the Modified Photo-Fenton Reaction included two diverse pathways and tert-butyl formate (TBF) was identified to be the major degradation intermediate. Attributed to the high solubility, stability, and reactivity of the ferric-citrate complexes in the near neutral condition, this Modified Photo-Fenton reaction is a promising treatment process for high concentrations of MTBE under or near a neutral pH.

과산화수소 연속주입식 광펜톤산화공정에 의한 4-염화페놀 분해연구

김일규 대한상하수도학회 2013 상하수도학회지 Vol.27 No.1

The degradation of 4-chlorophenol(4-CP) by various AOPs(Advanced Oxidation Processes) with continuous feeding of H2O2, including the ultraviolet/hydrogen peroxide, the Fenton and the photo-Fenton process has been investigated. The photo-Fenton process showed the highest removal efficiency for degradation of 4-chlorophenol than those of other AOPs including the Fenton process and the combined UV process with continuous feeding of H2O2. In the photo-Fenton process, the optimal experimental condition for 4-CP degradation was obtained at pH 3. Also the 4-CP removal efficiency increased with decreasing of the initial 4-CP concentration. 4-chlorocatechol and 4-chlororesorcinol were identified as photo-Fenton reaction intermediates, and the degradation pathways of 4-CP in the aqueous phase during the photo-Fenton reaction were proposed.

Oxidation of geosmin and 2-methylisoborneol by the photo-Fenton process: Kinetics, degradation intermediates, and the removal of microcystin-LR and trihalomethane from Nak-Dong River water, South Korea

Park, Jeong-Ann,Nam, Hye-Lim,Choi, Jae-Woo,Ha, Junsoo,Lee, Sang-Hyup Elsevier 2017 CHEMICAL ENGINEERING JOURNAL -LAUSANNE- Vol.313 No.-

<P><B>Abstract</B></P> <P>Due to the increased intensity and frequency of cyanobacterial blooms, taste and odor (T&O) causing compounds, geosmin (GSM) and 2-methylisoborneol (MIB), have become a cause for great concern in drinking water treatment plants (DWTPs). Advanced oxidation processes (AOPs) have been studied for the removal of GSM and MIB. However, in this work, a photo-Fenton treatment was investigated for the first time for the degradation of GSM and MIB in both synthetic and Nak-Dong River water from DWTPs. Synthetic water-based experiments were performed to investigate the optimal operation conditions for the removal of GSM and MIB, and the effects of water quality parameters of the photo-Fenton process, including the Fe(II)/H<SUB>2</SUB>O<SUB>2</SUB> concentration, reaction time, pH, organic matter, and initial concentration of GSM and MIB. Degradation intermediates of dehydration and ring-opening were observed during the photo-Fenton process. The optimal conditions were determined to be 2mg/L Fe(II) and 20mg/L H<SUB>2</SUB>O<SUB>2</SUB> at pH 5 considering both efficiency and cost. The degradation efficiency was lower than that of DI water, mainly because of the pH (7.2–7.6). Nevertheless, the photo-Fenton process meets the guideline levels (20ng/L) in South Korea when the initial concentration in the river water is below 50ng/L. In addition, trihalomethanes (THMs) and microcystin-LR (MC-LR), derived from cyanobacterial blooms and another cause for concern, were degraded effectively using the photo-Fenton process on the river water.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The photo-Fenton process is effective method to remove taste and odor compounds. </LI> <LI> Degradation intermediates are related with dehydration and ring opening pathways. </LI> <LI> Degradation efficiency of GSM and MIB was mainly affected by pH. </LI> <LI> The photo-Fenton process also removes THMs and MC-LR in Nak-Dong River water. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Synergistically enhanced photocatalytic activity of graphitic carbon nitride and WO₃ nanohybrids mediated by photo-Fenton reaction and H₂O₂

Yoon, Minji,Oh, Youngtak,Hong, Sugyeong,Lee, June Sang,Boppella, Ramireddy,Kim, Sun Hee,Marques Mota, Filipe,Kim, Sang Ouk,Kim, Dong Ha Elsevier 2017 Applied Catalysis B Vol.206 No.-

<P><B>Abstract</B></P> <P>The development of solar energy conversion in the production of fuels, water splitting and water purification systems, has become an important sidestep for traditional fossil energy. Herein we have investigated the coupling effect of a Photo-Fenton system on a conventional photocatalytic reaction with a novel Fe-doped C<SUB>3</SUB>N<SUB>4</SUB>/WO<SUB>3</SUB> hybrid structure. The decomposition of <I>p</I>-nitrophenol was selected as a model reaction in the context of the degradation of organic pollutants. Heterojunction nanocomposites consisting of g-C<SUB>3</SUB>N<SUB>4</SUB> nanosheets and WO<SUB>3</SUB> nanoparticles were shown to facilitate the separation of photo-induced electron and hole pairs. The photocatalytic activity was further maximized as a result of a synergism of the ‘Photo-Fenton cycle’ with Fe(II) or Fe(III)-doping in the presence of H<SUB>2</SUB>O<SUB>2</SUB> to generate additional hydroxyl radicals. As a result, after 4h under visible light the degradation of <I>p</I>-nitrophenol could be remarkably enhanced from 10 to 90% compared to the g-C<SUB>3</SUB>N<SUB>4</SUB> reference. To the best of our knowledge, this is the first time such a striking increase is reported with a Photo-Fenton system applied in the present photocatalytic system. The significance of the presence of hydroxyl radicals in the photo-Fenton performance of Fe-doped C<SUB>3</SUB>N<SUB>4</SUB>/WO<SUB>3</SUB> was assessed by scavenger and fluorescence tests. Additional light was shed into the reaction mechanism <I>via</I> spin trapping enabled by <I>in-situ</I> electron paramagnetic resonance.</P> <P><B>Highlights</B></P> <P> <UL> <LI> First report of Fe-coordinated C<SUB>3</SUB>N<SUB>4</SUB>/WO<SUB>3</SUB> hybrids as an effective photo-Fenton system. </LI> <LI> Degradation of PNP enhanced from 10 to 90% under visible light, compared to C<SUB>3</SUB>N<SUB>4</SUB>. </LI> <LI> C<SUB>3</SUB>N<SUB>4</SUB> and WO<SUB>3</SUB> facilitate the separation of photo-induced electron and hole pairs. </LI> <LI> Fe-species generate additional hydroxyl radicals in the presence of H<SUB>2</SUB>O<SUB>2</SUB>. </LI> <LI> Complementary analysis shed light on the mechanism and significance of OH radicals. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

광펜톤반응과 펜톤반응에 의한 수중 클로로페놀 분해비교연구

김일규,김현승 대한상하수도학회 2011 상하수도학회지 Vol.25 No.4

The degradation of 4-chlorophenol by various AOPs(Advanced Oxidation Processes) including the Fenton and the photo-Fenton process has been examined. In sole Fe, UV or H2O2 process without combination, low removal efficiencies have been achieved. But the photo-Fenton process showed higher removal efficiency for degradation of 4-chlorophenol than those of other AOPs including the Fenton process. Generally more hydrogen peroxide was required to achieve higher removal efficiencies of 4-CP at constant dosage of FeSO4 in both of the Fenton and the photo-Fenton processes. Based on the results, The photo-Fenton process is proposed to be the most efficient alternative for degradation of 4-chlorophenol among the processes studied in this research.

광펜톤 반응에 의한 수중 2-클로로페놀 분해특성연구

김일규 대한상하수도학회 2012 상하수도학회지 Vol.26 No.6

The degradation of 2-chlorophenol(2-CP) by various AOPs(Advanced Oxidation Processes) including the photo-Fenton process has been examined. In sole Fe2+, UV or H2O2 process without combination, low removal efficiencies have been achieved. But the photo-Fenton process showed higher removal efficiency for degradation of 2-chlorophenol than those of other AOPs including the Fenton process and the UV processes. In the photo-Fenton process, the optimal experimental conditions of 2-chlorophenol degradation were obtained at pH 3 and the Fe2+/H2O2 molar ratio of 1. Also the 2-chlorophenol removal efficiency increased with decreasing of the initial 2-chlorophenol concentration. 3-chlorocatechol and chlorohydroquinone were identified as photo-Fenton reaction intermediates, and a degradation pathway of 2-chlorophenol in the aqueous phase during the photo-Fenton reaction was proposed.

Heterogeneous photo-Fenton oxidation of methylene blue using CdS-carbon nanotube/TiO2 under visible light

Jihyun R. Kim,Eunsung Kan 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.21 No.1

Heterogeneous photo-Fenton oxidation using CdS/multi-walled carbon nanotube-TiO2 (CdS/MWCNTTiO2)under visible light relied on combination of the photocatalytic, photo-Fenton and photosensitizingoxidation. The photo-Fenton reactions resulted in much faster and higher removal ofmethylene blue and total organic carbon than the dark Fenton oxidation and the photocatalyticdegradation alone at the selected conditions. The optimummolar ratio of [methylene blue]:[H2O2]:[Fe3+](1:12:3.4) in the photo-Fenton oxidation indicated cost-effectiveness of the process. The scavengingtests of the hydroxyl radicals and the valence holes suggested that the hydroxyl radical-driven oxidationwas the major step among the multiple reactions in the photo-Fenton oxidation.

Photo-Fenton 공정을 이용한 축산폐수처리시 운전인자의 최적조건

박재홍 ( Jae Hong Park ),장순웅 ( Soon Woong Chang ),조일형 ( Il Hyoung Cho ) 한국물환경학회 2005 한국물환경학회지 Vol.21 No.3

In this study, photochemical advanced oxidation processes (AOPs) utilizing the Photo Fenton reaction (Fe^(2+)+H₂O₂+UV) were investigated in lab-scale experiments for the treatment of livestock wastewater. For the experimets, the livestock wastewater was pretreated by coagulation with 3,000 ㎎/L FeCl₃. The optimal conditions for Photo-Fenton processes were determined: pH was 5, the concentration of ferrous ion (Fe Ⅱ) was 0.01 M. The concentration of hydrogen peroxide was 0.1 M, and molar ratio (Fe^(2+)/H₂O₂) was 0.1. The optimal reaction time was 80 min. Under the optimal condition of Photo-Fenton process, chemical oxygen demand (COD), color and fecal coliform removal efficiencies were about 79, 70, and 99.4%, respectively and sludge production was 7.5 mL from 100 mL of solution.

Degradation of 2-chlorophenol by Fenton and photo-Fenton processes

김일규,홍성훈,이제근,권병혁 한국화학공학회 2008 Korean Journal of Chemical Engineering Vol.25 No.1

The photodegradation of a specific organic polutant using the Fenton and the photo-Fenton processesdegradation of 2-chlorophenol (2-CP) were investigated. The dependence on the following experimental conditionshad been evaluated: initial pH (1.0-9.0), hydrogen peroxide (0.67-2 mM), ferrous ions (0.1-2 mM), initial concentra-tion of 2-CP (0.1-2 mM). The optimal experimental conditions were 1 mM H2O2, 1 mM ferrous ion and pH 3.0. Underthe optimal conditions, the degradation efficiency of 2-CP in the photo-Fenton process was enhanced 4% more thanthat of the Fenton process. Experimental results about the degradation of 2-CP show that UV irradiation improves thep-benzoquinone.