The degradation of partially hydrolyzed polyacrylamide(HPAM) found in alkaline/surfactant/polymer flooding sewage was investigated using Fenton-type reagents. Different Fenton reagent treatments for HPAM degradation w...The degradation of partially hydrolyzed polyacrylamide(HPAM) found in alkaline/surfactant/polymer flooding sewage was investigated using Fenton-type reagents. Different Fenton reagent treatments for HPAM degradation were compared. The effects of pH, hydrogen peroxide(H_(2)O_(2)), ferrous ion(Fe^(2+)), and tartaric ion(C_(4)H_(4)O_(6)^(2-)) concentrations were studied. The degradation reaction occurred within a wide range of pH(3–9). The HPAM degradation performance of photo-Fenton processes using solar light and UV were compared with that of the Fenton process. The degradation rate was found to be strongly dependent on the H_(2)O_(2)/Fe^(2+)/C_(4)H_(4)O_(6)^(2-)molar ratio. The HPAM degradation efficiency was 90%, and the chemical oxygen demand removal efficiency was 85%. HPAM could be degraded into a compound with a lower molecular weight, but it was difficult to achieve complete mineralization to CO_(2). The presence of intermediate products hindered further oxidation in the Fenton process.展开更多
In this paper it is presented the results of advanced oxidation of leachates from a technified sanitary landfill located in the State of Querétaro, Mexico. One characteristic of already stabilized leachates from ...In this paper it is presented the results of advanced oxidation of leachates from a technified sanitary landfill located in the State of Querétaro, Mexico. One characteristic of already stabilized leachates from sanitary landfills like this case, is their difficult degradation, mainly because the organic matter contained is recalcitrant. For the samples collect, four sites were selected, where three points per site were sampled, measuring at each site the parameters: temperature, pH, conductivity, redox potential (ORP) and dissolved oxygen (DO) and leachate samples were collected. On the other hand, the Chemical Oxygen Demand (COD) of crude leachates, leachates acidified and leachates oxidized by Fenton reagent and Ozone-UV combined were analyzed. COD was used to monitor the degradation kinetics. With the results, the ArcGIS software was applied to study the distribution of temperature, dissolved oxygen and COD mainly in the leachate lagoon. For the application of Fenton reagent in the crude leachate oxidation, the pH was first adjusted and Fe<sup>2+</sup>/H<sub>2</sub>O<sub>2</sub> ratio was optimized. The efficiency of Ozone-UV treatments was studied through COD degradation kinetics. The graphs of in (Ci/Co) vs time, showed that the kinetic processes are of order one, with very acceptable regression coefficients (R<sup>2</sup>) and extraordinarily similar speed constants (K). With Fenton oxidation, the highest percentage of COD degradation was achieved and with Ozone-UV oxidation, it was possible to practically degrade all the COD.展开更多
Nearly 91% of organic pollutants in Hong Kong leachate could be effectively removed by the UASB(upflow anaerobic sludge blanket) process followed by the fenton coagulation. The COD (chemical oxygen demand) of leachate...Nearly 91% of organic pollutants in Hong Kong leachate could be effectively removed by the UASB(upflow anaerobic sludge blanket) process followed by the fenton coagulation. The COD (chemical oxygen demand) of leachate was lowered from an average of 5620 mg/L to 1910 mg/L after the UASB treatment at 37℃, and was further lowered to 513 mg/L after fenton coagulation. The remaining refractory residues could be further removed by photochemical oxidation with the addition of H 2O 2. The BOD/COD ratio was greatly increased from 0.062 to 0.142, indicating the biodegradability of organic residues was improved. The photochemical oxidation for the fenton\|coagulation supernatant was most effective at pH 3\_4, with the addition of 800 mg/L of H 2O 2, and UV radiation time of 30 minutes. The final effluent contained only 148 mg/L of COD, 21 mg/L of BOD(biochemical oxygen demand) and 56 mg/L of TOC (total organic carbon).展开更多
Central composite design (CCD), the most popular design ofresponse surface methodology (RSM), was employed to investigate theeffect of total organic carbon (TOC) ratio of high molecular weightorganic matter (HMW) to l...Central composite design (CCD), the most popular design ofresponse surface methodology (RSM), was employed to investigate theeffect of total organic carbon (TOC) ratio of high molecular weightorganic matter (HMW) to low molecular weight organic matter (LMW),the LMW strength and molar ratio of hydrogen peroxide to ferrous ionon landfill leachate treatment by Fenton process. Based on theexperimental data, a response surface quadratic model in terms ofactual factors was obtained through analysis of variance (ANOVA).展开更多
High strength refractory organic stream is produced during the production of 2-phenylamino-3-methyl-6-di-n-butylaminofluoran (One Dye Black 2, abbr. ODB 2), a novel heat-sensitive material with a promising market. I...High strength refractory organic stream is produced during the production of 2-phenylamino-3-methyl-6-di-n-butylaminofluoran (One Dye Black 2, abbr. ODB 2), a novel heat-sensitive material with a promising market. In this study, a combination of acidificationprecipitation, primary biological treatment, Fenton's oxidation and another biological treatment was successfully used for the removal of COD from 18000-25000 mg/L to below 200 mg/L from the ODB 2 production wastewater in a pilot experiment. A COD removal of 70%-80% was achieved by acidification-precipitation under a pH of 2.5-3.0. The first step biodegradafion permitted an average COD removal of 70% under an hydraulic residence time (HRT) of 30 h. By batch tests, the optimum conditions of Fenton's oxidation were acquired as: Fe^2+ dose 6.0 mmol/L; H2O2 dose 3000 mg/L; and reaction time 6 h. The second step biological treatment could ensure an effluent COD below 200 mg/L under an HRT of 10 h following the Fenton's treatment.展开更多
The treatment of phenol wastewater with an ultraviolet source and an oxone generator by introducing salicylic acid as the capturer is described. The presence of HO during the phenol degradation has been proved. The i...The treatment of phenol wastewater with an ultraviolet source and an oxone generator by introducing salicylic acid as the capturer is described. The presence of HO during the phenol degradation has been proved. The impacts of factors such as acidity and reaction time on the HO formation are also discussed. The results demonstrate that HO ' generated from ozone/UV oxidation under a basic condition is the immediate cause of phenol degradation. At room temperature and a pH value of 9. 93, the degradation of phenol occurs rapidly within 0. 5 rain and the removal of phe- nol( 100 mg/L) is above 98. 5% within 15 min; in the meantime, the pH value declines gradually with the degradation of phenol. A discussion about the formation and the transformation of the intermediate products during phenol degradation is included.展开更多
Abstract [ Objective] The degradation conditions and course of reactive brilliant red X-3B by Fenton oxidation was investigated to understand the feasibility of using Fenton oxidation for dye removal. [Metbed] By usin...Abstract [ Objective] The degradation conditions and course of reactive brilliant red X-3B by Fenton oxidation was investigated to understand the feasibility of using Fenton oxidation for dye removal. [Metbed] By using Fenton oxidation, the degradation conditions of reactive brilliant red X-3B wastewater was studied in different initial concentrations, then analyzed its degradation products and process through gas chromatography-mass spectrometer (GC-MS). [ Remit] When H202:Fe2+ (molar ratio) =3.1, the removal rate of CODc, was the highest. With the increase of Fe2+ dos- age, the wastewater became red and more deposits generated. As CODc, of wastewater was 200,400 and 800 mg/L, the dosage of H202 was 0.5, 1.0 and 3.5 ml respectively, and the best initial pH of the wastewater was 4 -5, the removal rate of GODc, reached the maximum values. In addition, Fenton reaction was very fast, that is, most degradation occurred in the first 5 min. [ Cenclmion] Fenton oxidation technology is practical and efficient in the declradation of dves which are mineralized difficultly.展开更多
The performance of UV/H 2O 2, UV/O 3 and UV/H 2O 2/O 3 oxidation systems for treating spent caustic from an ethylene plant was investigated. In UV/H 2O 2 system, with the increase of H 2O 2 dosage, removal e...The performance of UV/H 2O 2, UV/O 3 and UV/H 2O 2/O 3 oxidation systems for treating spent caustic from an ethylene plant was investigated. In UV/H 2O 2 system, with the increase of H 2O 2 dosage, removal efficiencies of COD and the ratio of biochemical oxygen demand(BOD) to chemical oxygen demand(COD) of the effluent were increased and a better performance was obtained than the H 2O 2 system alone. In UV/H 2O 2 system, removal efficiency of COD reach 68% under the optimum condition, and BOD/COD ratio was significantly increased from 0 22 to 0 52. In UV/O 3 system, with the increase of O 3 dosage, removal efficiency of COD and BOD/COD ratio were increased, and a better performance was obtained than the O 3 system alone. Under the optimum condition, removal efficiency of COD was 54%, and BOD/COD ratio was significantly increased from 0 22 to 0 48. In UV/H 2O 2/O 3 system, COD removal efficiency was found to be 22.0% higher than UV/O 3 system.展开更多
The mineralization of phenol in aerated electrochemical oxidation has been investigated.The results show that a cathodic Fenton process can occur when the Ti-0.3Mo-0.8Ni alloy material is used as cathode in solution c...The mineralization of phenol in aerated electrochemical oxidation has been investigated.The results show that a cathodic Fenton process can occur when the Ti-0.3Mo-0.8Ni alloy material is used as cathode in solution containing ferric or ferrous ions; moreover,the reinforcement of cathodic Fenton process on the total organic carbon (TOC) removal rate of phenol is quite distinct.Among the metallic ions investigated,the ferric ion is the best catalyst for the electrochemical mineralization of phenol at initial...展开更多
Density functional theory(DFT) quantum chemical method was used to study the process of meta-xylene Fenton oxidation. The EHOMO energies of meta-xylene molecules are higher, so they have better ability to provide el...Density functional theory(DFT) quantum chemical method was used to study the process of meta-xylene Fenton oxidation. The EHOMO energies of meta-xylene molecules are higher, so they have better ability to provide electron and prone to the nucleophilic reaction. M-xylene mainly reacts with OH free radical in addition reactions. And the position of C(6) is most likely to react with the OH free radical, rather than the C(3), which is the most difficult to occur. According to all the above results, the most likely reaction mechanism of advanced oxidation degradation of meta-xylene is determined.展开更多
Wastewater after chemical flooding is difficult to be treated by biological methods due to the residual chemicals in the wastewater. Fenton oxidation, which has been widely applied to detoxifying hazardous organic com...Wastewater after chemical flooding is difficult to be treated by biological methods due to the residual chemicals in the wastewater. Fenton oxidation, which has been widely applied to detoxifying hazardous organic compounds and improving the biodegradability of these compounds, can solve this problem. So, in this paper, Fenton oxidation was used to enhance the biodegradability of the wastewater after chemical flooding. The op- timum operating conditions for the Fenton oxidation process were 2.5 g/L Fe2 + , 600 mg/L H202 and 30 rain of treatment time. The wastewater pre- treated by Fenton oxidation was treated by aerobic activated sludge. It was found that a small amount of H202 can significantly increase both the biodegradation rate and extent of the wastewater. The effluent CODc, and HPAM contents were 260 and 94 mg/L respectively after the aerobic bio- logical process with the biodegradation time of 24 h. After Fenton oxidation combining with biodegradation, the total CODc, removal efficiency was up to 90%, and polymer and oil degrading efficiencies were 95% and 92% respectively.展开更多
A series of batch-scale experiments were completed to investigate the effects of operational parameters on chemical oxygen demand (COD) removal by Fenton reagent for antibiotic pharmaceutical wastewater (APW). The sig...A series of batch-scale experiments were completed to investigate the effects of operational parameters on chemical oxygen demand (COD) removal by Fenton reagent for antibiotic pharmaceutical wastewater (APW). The significance of five operational factors including the mass ratio of H2O2/COD (g/g), the mole ratio of H2O2/Fe2+ (mol/mol), initial pH, oxidation temperature T, and reaction time t were evaluated statistically by Box-Behnken design (BBD). It was found that the five parameters were all significant to the COD removal efficiency by t-test, as well as the interactions between mass ratio/reaction time and oxidation temperature/reaction. The optimal COD removal efficiency (89.50%) was achieved when the mass ratio of H2O2/COD and the mole ratio of H2O2/Fe2+ were 3.00 and 5.00 respectively, with pH value of 3.68 at 298K for 72min reaction. A quadratic regression model with 0.9907 regression coefficient (R2) was developed which had good agreement to the experimental data.展开更多
基金the Northeast Petroleum University Youth Science Foundation (No. 2019QNL-35)Guiding Science and Technology Plan Project of Daqing (No. zd-2021-39)。
文摘The degradation of partially hydrolyzed polyacrylamide(HPAM) found in alkaline/surfactant/polymer flooding sewage was investigated using Fenton-type reagents. Different Fenton reagent treatments for HPAM degradation were compared. The effects of pH, hydrogen peroxide(H_(2)O_(2)), ferrous ion(Fe^(2+)), and tartaric ion(C_(4)H_(4)O_(6)^(2-)) concentrations were studied. The degradation reaction occurred within a wide range of pH(3–9). The HPAM degradation performance of photo-Fenton processes using solar light and UV were compared with that of the Fenton process. The degradation rate was found to be strongly dependent on the H_(2)O_(2)/Fe^(2+)/C_(4)H_(4)O_(6)^(2-)molar ratio. The HPAM degradation efficiency was 90%, and the chemical oxygen demand removal efficiency was 85%. HPAM could be degraded into a compound with a lower molecular weight, but it was difficult to achieve complete mineralization to CO_(2). The presence of intermediate products hindered further oxidation in the Fenton process.
文摘In this paper it is presented the results of advanced oxidation of leachates from a technified sanitary landfill located in the State of Querétaro, Mexico. One characteristic of already stabilized leachates from sanitary landfills like this case, is their difficult degradation, mainly because the organic matter contained is recalcitrant. For the samples collect, four sites were selected, where three points per site were sampled, measuring at each site the parameters: temperature, pH, conductivity, redox potential (ORP) and dissolved oxygen (DO) and leachate samples were collected. On the other hand, the Chemical Oxygen Demand (COD) of crude leachates, leachates acidified and leachates oxidized by Fenton reagent and Ozone-UV combined were analyzed. COD was used to monitor the degradation kinetics. With the results, the ArcGIS software was applied to study the distribution of temperature, dissolved oxygen and COD mainly in the leachate lagoon. For the application of Fenton reagent in the crude leachate oxidation, the pH was first adjusted and Fe<sup>2+</sup>/H<sub>2</sub>O<sub>2</sub> ratio was optimized. The efficiency of Ozone-UV treatments was studied through COD degradation kinetics. The graphs of in (Ci/Co) vs time, showed that the kinetic processes are of order one, with very acceptable regression coefficients (R<sup>2</sup>) and extraordinarily similar speed constants (K). With Fenton oxidation, the highest percentage of COD degradation was achieved and with Ozone-UV oxidation, it was possible to practically degrade all the COD.
文摘Nearly 91% of organic pollutants in Hong Kong leachate could be effectively removed by the UASB(upflow anaerobic sludge blanket) process followed by the fenton coagulation. The COD (chemical oxygen demand) of leachate was lowered from an average of 5620 mg/L to 1910 mg/L after the UASB treatment at 37℃, and was further lowered to 513 mg/L after fenton coagulation. The remaining refractory residues could be further removed by photochemical oxidation with the addition of H 2O 2. The BOD/COD ratio was greatly increased from 0.062 to 0.142, indicating the biodegradability of organic residues was improved. The photochemical oxidation for the fenton\|coagulation supernatant was most effective at pH 3\_4, with the addition of 800 mg/L of H 2O 2, and UV radiation time of 30 minutes. The final effluent contained only 148 mg/L of COD, 21 mg/L of BOD(biochemical oxygen demand) and 56 mg/L of TOC (total organic carbon).
基金Supported by the Delaware Solid Waste Authority, Dover DE, USA and China Scholarship Council (No. 97842039).
文摘Central composite design (CCD), the most popular design ofresponse surface methodology (RSM), was employed to investigate theeffect of total organic carbon (TOC) ratio of high molecular weightorganic matter (HMW) to low molecular weight organic matter (LMW),the LMW strength and molar ratio of hydrogen peroxide to ferrous ionon landfill leachate treatment by Fenton process. Based on theexperimental data, a response surface quadratic model in terms ofactual factors was obtained through analysis of variance (ANOVA).
基金Project supported by the National Natural Science Foundation of China (No.50525824)Natural Science Fund of Xinjiang Province of China (No.200432109).
文摘High strength refractory organic stream is produced during the production of 2-phenylamino-3-methyl-6-di-n-butylaminofluoran (One Dye Black 2, abbr. ODB 2), a novel heat-sensitive material with a promising market. In this study, a combination of acidificationprecipitation, primary biological treatment, Fenton's oxidation and another biological treatment was successfully used for the removal of COD from 18000-25000 mg/L to below 200 mg/L from the ODB 2 production wastewater in a pilot experiment. A COD removal of 70%-80% was achieved by acidification-precipitation under a pH of 2.5-3.0. The first step biodegradafion permitted an average COD removal of 70% under an hydraulic residence time (HRT) of 30 h. By batch tests, the optimum conditions of Fenton's oxidation were acquired as: Fe^2+ dose 6.0 mmol/L; H2O2 dose 3000 mg/L; and reaction time 6 h. The second step biological treatment could ensure an effluent COD below 200 mg/L under an HRT of 10 h following the Fenton's treatment.
文摘The treatment of phenol wastewater with an ultraviolet source and an oxone generator by introducing salicylic acid as the capturer is described. The presence of HO during the phenol degradation has been proved. The impacts of factors such as acidity and reaction time on the HO formation are also discussed. The results demonstrate that HO ' generated from ozone/UV oxidation under a basic condition is the immediate cause of phenol degradation. At room temperature and a pH value of 9. 93, the degradation of phenol occurs rapidly within 0. 5 rain and the removal of phe- nol( 100 mg/L) is above 98. 5% within 15 min; in the meantime, the pH value declines gradually with the degradation of phenol. A discussion about the formation and the transformation of the intermediate products during phenol degradation is included.
基金Supported by Key Laboratory Project of Water Pollution Control of Guangdong Province,China (2010009)
文摘Abstract [ Objective] The degradation conditions and course of reactive brilliant red X-3B by Fenton oxidation was investigated to understand the feasibility of using Fenton oxidation for dye removal. [Metbed] By using Fenton oxidation, the degradation conditions of reactive brilliant red X-3B wastewater was studied in different initial concentrations, then analyzed its degradation products and process through gas chromatography-mass spectrometer (GC-MS). [ Remit] When H202:Fe2+ (molar ratio) =3.1, the removal rate of CODc, was the highest. With the increase of Fe2+ dos- age, the wastewater became red and more deposits generated. As CODc, of wastewater was 200,400 and 800 mg/L, the dosage of H202 was 0.5, 1.0 and 3.5 ml respectively, and the best initial pH of the wastewater was 4 -5, the removal rate of GODc, reached the maximum values. In addition, Fenton reaction was very fast, that is, most degradation occurred in the first 5 min. [ Cenclmion] Fenton oxidation technology is practical and efficient in the declradation of dves which are mineralized difficultly.
文摘The performance of UV/H 2O 2, UV/O 3 and UV/H 2O 2/O 3 oxidation systems for treating spent caustic from an ethylene plant was investigated. In UV/H 2O 2 system, with the increase of H 2O 2 dosage, removal efficiencies of COD and the ratio of biochemical oxygen demand(BOD) to chemical oxygen demand(COD) of the effluent were increased and a better performance was obtained than the H 2O 2 system alone. In UV/H 2O 2 system, removal efficiency of COD reach 68% under the optimum condition, and BOD/COD ratio was significantly increased from 0 22 to 0 52. In UV/O 3 system, with the increase of O 3 dosage, removal efficiency of COD and BOD/COD ratio were increased, and a better performance was obtained than the O 3 system alone. Under the optimum condition, removal efficiency of COD was 54%, and BOD/COD ratio was significantly increased from 0 22 to 0 48. In UV/H 2O 2/O 3 system, COD removal efficiency was found to be 22.0% higher than UV/O 3 system.
基金the Hi-Tech Research and Development Program (863) of China (No.2005AA601010-02-2)the Science Pilot Plan of the Science and Technology Bureau of Wuhan City (No.20066009138-02).
文摘The mineralization of phenol in aerated electrochemical oxidation has been investigated.The results show that a cathodic Fenton process can occur when the Ti-0.3Mo-0.8Ni alloy material is used as cathode in solution containing ferric or ferrous ions; moreover,the reinforcement of cathodic Fenton process on the total organic carbon (TOC) removal rate of phenol is quite distinct.Among the metallic ions investigated,the ferric ion is the best catalyst for the electrochemical mineralization of phenol at initial...
基金Supported by the research and practice project of scientific and technological innovation of school enterprise cooperation in Guangdong University of Petrochemical Technology(660648)
文摘Density functional theory(DFT) quantum chemical method was used to study the process of meta-xylene Fenton oxidation. The EHOMO energies of meta-xylene molecules are higher, so they have better ability to provide electron and prone to the nucleophilic reaction. M-xylene mainly reacts with OH free radical in addition reactions. And the position of C(6) is most likely to react with the OH free radical, rather than the C(3), which is the most difficult to occur. According to all the above results, the most likely reaction mechanism of advanced oxidation degradation of meta-xylene is determined.
基金supported by Zhejiang Provincial Natural Science Foundation of China under Grant No.LQ13D060001 and No.LY14D060003Science and Technology Plan Project of Zhoushan City under Grant No.2014C41004
文摘Wastewater after chemical flooding is difficult to be treated by biological methods due to the residual chemicals in the wastewater. Fenton oxidation, which has been widely applied to detoxifying hazardous organic compounds and improving the biodegradability of these compounds, can solve this problem. So, in this paper, Fenton oxidation was used to enhance the biodegradability of the wastewater after chemical flooding. The op- timum operating conditions for the Fenton oxidation process were 2.5 g/L Fe2 + , 600 mg/L H202 and 30 rain of treatment time. The wastewater pre- treated by Fenton oxidation was treated by aerobic activated sludge. It was found that a small amount of H202 can significantly increase both the biodegradation rate and extent of the wastewater. The effluent CODc, and HPAM contents were 260 and 94 mg/L respectively after the aerobic bio- logical process with the biodegradation time of 24 h. After Fenton oxidation combining with biodegradation, the total CODc, removal efficiency was up to 90%, and polymer and oil degrading efficiencies were 95% and 92% respectively.
基金Major Science and Technology Programs for Water Pollution Control and Treatment,China(No.2009ZX07317-006-02,No.2009ZX07317-008-01)State Key Laboratory of Urban Water Resource and Environment,China(No.2010DX02)
文摘A series of batch-scale experiments were completed to investigate the effects of operational parameters on chemical oxygen demand (COD) removal by Fenton reagent for antibiotic pharmaceutical wastewater (APW). The significance of five operational factors including the mass ratio of H2O2/COD (g/g), the mole ratio of H2O2/Fe2+ (mol/mol), initial pH, oxidation temperature T, and reaction time t were evaluated statistically by Box-Behnken design (BBD). It was found that the five parameters were all significant to the COD removal efficiency by t-test, as well as the interactions between mass ratio/reaction time and oxidation temperature/reaction. The optimal COD removal efficiency (89.50%) was achieved when the mass ratio of H2O2/COD and the mole ratio of H2O2/Fe2+ were 3.00 and 5.00 respectively, with pH value of 3.68 at 298K for 72min reaction. A quadratic regression model with 0.9907 regression coefficient (R2) was developed which had good agreement to the experimental data.