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
The performances and kinetic parameters of Fenton oxidation of 2,4-and 2,6-dinitrotoluene(DNT)in water-acetone mixtures and explosive contaminated soil washing-out solutions were investigated at a laboratory scale.The...The performances and kinetic parameters of Fenton oxidation of 2,4-and 2,6-dinitrotoluene(DNT)in water-acetone mixtures and explosive contaminated soil washing-out solutions were investigated at a laboratory scale.The experimental results show that acetone can be a significant hydroxyl radical scavenger and result in serious inhibition of Fenton oxidation of 2,4-and 2,6-DNT.Although no serious inhibition was found in contaminated soil washing-out solutions,longer reaction time was needed to remove 2,4-and 2,6-DNT completely,mainly due to the competition of hydroxyl radicals.Fenton oxidation of 2,4-and 2,6-DNT fit well with the first-order kinetics and the presence of acetone also reduced DNT’s degradation kinetics.Based on the comparison and matching of retention time and ultraviolet(UV)spectra between high performance liquid chromatography(HPLC)and standards,the following reaction pathway for 2,4-DNT primary degradation was proposed:2,4-DNT→2,4-dinitro-benzaldehyde→2,4-dinitrobenzoic acid→1,3-dinitrobenzene→3-nitrophenol.展开更多
The pulp and paper industry produces a large amount of colored effluent in the pulping,bleaching,and papermaking processes.The wastewater from the pulp washing and bleaching stages is also known as mid-stage pulping e...The pulp and paper industry produces a large amount of colored effluent in the pulping,bleaching,and papermaking processes.The wastewater from the pulp washing and bleaching stages is also known as mid-stage pulping effluent,which is difficult to treat due to its toxicity and dark dolor.This paper reports a novel Fe/C micro-electrolysis process for the treatment of the mid-stage pulping effluent.Results show that this process is effective in removing the color under optimal reaction conditions.Scanning electron microscopy(SEM)and Fourier transform infrared spectroscopy(FTIR)analyses indicate that the colored pollutants were removed from the wastewater in the Fe/C micro-electrolysis by adsorption,collection and filtration mechanisms.The Fe2+ions produced in the micro-electrolysis process functioned as Fenton’s reagents with H2O2 in the follow-up oxidation stage,which enhanced the removal of chemical oxygen demand(COD)and color.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
The effectiveness,viability and feasibility of applying Fenton reactants in treating soil contaminated with automatic gas oil(AGO)was investigated ex-situ.Soil was simulated to achieve 10%contamination using AGO(diese...The effectiveness,viability and feasibility of applying Fenton reactants in treating soil contaminated with automatic gas oil(AGO)was investigated ex-situ.Soil was simulated to achieve 10%contamination using AGO(diesel)as the primary contaminant.Physicochemical properties and heavy metal contents were characterized using standard analytical methods,while total petroleum hydrocarbon(TPH)content was determined by molecular spectroscopy.An investigation of the soil physicochemical properties shows severe impact of the contaminant on pH,conductivity,phosphorus and(TPH)content.The optimum concentration of Fenton reactants determined from the optimization study was found to be 350,000 ppm H2O2 and 600 ppm FeSO4 at optimum room temperature range of 27e30C and optimum pH of 4.7.The highly exothermic Fenton oxidation treatment resulted in significant decrease in TPH content by 87.6%after 6 h of periodic monitoring;breaking down the hydrocarbons into non-toxic environmental friendly products.Kinetics analysis and evaluation shows pseudo-first order mechanism for the Fenton treatment with a calculated rate constant of 0.226 h-1 and half life of 3 h 4 min.The Fenton method is found to be very effective and efficient not only for the removal of the diesel contaminant,but also for the restoration of lost physicochemical properties occasioned by the effect of the contaminant.The environmental friendliness and fast response time towards effective clean up gives the technique a cutting edge advantage over other conventional methods.It therefore presents potentials for remediation experts in outright applications on real field challenges.展开更多
The primary aim of this study is inert COD removal from leachate nanofiltration concentrate because of its high concentration of resistant organic pollutants.Within this framework,this study focuses on the treatabilit...The primary aim of this study is inert COD removal from leachate nanofiltration concentrate because of its high concentration of resistant organic pollutants.Within this framework,this study focuses on the treatability of leachate nanofiltration concentrate through Fenton oxidation and optimization of process parameters to reach the maximum pollutant removal by using response surface methodology(RSM).Initial pH,Fe2+concentration,H_(2)O_(2)/Fe^(2+)molar ratio and oxidation time are selected as the independent variables,whereas total COD,color,inert COD and UV254 removal are selected as the responses.According to the ANOVA results,the R^(2) values of all responses are found to be over 95%.Under the optimum conditions determined by the model(pH:3.99,Fe^(2+):150 mmol/L,H_(2)O_(2)/Fe^(2+):3.27 and oxidation time:84.8 min),the maximum COD removal efficiency is determined as 91.4%by the model.The color,inert COD and UV254 removal efficiencies are determined to be 99.9%,97.2%and 99.5%,respectively,by the model,whereas the total COD,color,inert COD and UV254 removal efficiencies are found respectively to be 90%,96.5%,95.3%and 97.2%,experimentally under the optimum operating conditions.The Fenton process improves the biodegradability of the leachate NF concentrate,increasing the BOD5/COD ratio from the value of 0.04 to the value of 0.4.The operational cost of the process is calculated to be 0.238€/g COD_(removed).The results indicate that the Fenton oxidation process is an efficient and economical technology in improvement of the biological degradability of leachate nanofiltration concentrate and in removal of resistant organic pollutants.展开更多
A new Cu(Ⅱ)coordination polymer,{[Cu3(oba)2(μ^3-OH)2(H2O)2].6H2O}n(H2 oba=4,4’-oxydibenzoic acid),was synthesized by the solvothermal route and characterized by IR,TGA and XRD.The complex crystallizes in the monocl...A new Cu(Ⅱ)coordination polymer,{[Cu3(oba)2(μ^3-OH)2(H2O)2].6H2O}n(H2 oba=4,4’-oxydibenzoic acid),was synthesized by the solvothermal route and characterized by IR,TGA and XRD.The complex crystallizes in the monoclinic system,space group P21/c with a=5.957(6),b=29.746(3),c=9.351(7)A,β=125.709(4)°,V=1345.4(2)A3,Z=2,C28H36Cu3O20,Mr=883.09,Dc=1.913 g/cm^3,F(000)=782,μ=2.427 mm-1,R=0.0780 and wR=0.1688 for 3120 observed reflections with I>2σ(I).The complex forms a 3D framework based on rare infinite rod-shaped secondary building units(SBUs),and C-H…πinteractions play an important role in stabilizing the 3D supramolecular architecture.It shows excellent catalytic activities for the degradation of safranin O(SO)and methylene blue(MB)dyes in aqueous solution under UV light irradiation.Furthermore,the apparent rate constants have also been investigated.展开更多
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.
基金This work was supported by the National Natural Science Foundation of China(Grant No.20676078).
文摘The performances and kinetic parameters of Fenton oxidation of 2,4-and 2,6-dinitrotoluene(DNT)in water-acetone mixtures and explosive contaminated soil washing-out solutions were investigated at a laboratory scale.The experimental results show that acetone can be a significant hydroxyl radical scavenger and result in serious inhibition of Fenton oxidation of 2,4-and 2,6-DNT.Although no serious inhibition was found in contaminated soil washing-out solutions,longer reaction time was needed to remove 2,4-and 2,6-DNT completely,mainly due to the competition of hydroxyl radicals.Fenton oxidation of 2,4-and 2,6-DNT fit well with the first-order kinetics and the presence of acetone also reduced DNT’s degradation kinetics.Based on the comparison and matching of retention time and ultraviolet(UV)spectra between high performance liquid chromatography(HPLC)and standards,the following reaction pathway for 2,4-DNT primary degradation was proposed:2,4-DNT→2,4-dinitro-benzaldehyde→2,4-dinitrobenzoic acid→1,3-dinitrobenzene→3-nitrophenol.
文摘The pulp and paper industry produces a large amount of colored effluent in the pulping,bleaching,and papermaking processes.The wastewater from the pulp washing and bleaching stages is also known as mid-stage pulping effluent,which is difficult to treat due to its toxicity and dark dolor.This paper reports a novel Fe/C micro-electrolysis process for the treatment of the mid-stage pulping effluent.Results show that this process is effective in removing the color under optimal reaction conditions.Scanning electron microscopy(SEM)and Fourier transform infrared spectroscopy(FTIR)analyses indicate that the colored pollutants were removed from the wastewater in the Fe/C micro-electrolysis by adsorption,collection and filtration mechanisms.The Fe2+ions produced in the micro-electrolysis process functioned as Fenton’s reagents with H2O2 in the follow-up oxidation stage,which enhanced the removal of chemical oxygen demand(COD)and color.
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The effectiveness,viability and feasibility of applying Fenton reactants in treating soil contaminated with automatic gas oil(AGO)was investigated ex-situ.Soil was simulated to achieve 10%contamination using AGO(diesel)as the primary contaminant.Physicochemical properties and heavy metal contents were characterized using standard analytical methods,while total petroleum hydrocarbon(TPH)content was determined by molecular spectroscopy.An investigation of the soil physicochemical properties shows severe impact of the contaminant on pH,conductivity,phosphorus and(TPH)content.The optimum concentration of Fenton reactants determined from the optimization study was found to be 350,000 ppm H2O2 and 600 ppm FeSO4 at optimum room temperature range of 27e30C and optimum pH of 4.7.The highly exothermic Fenton oxidation treatment resulted in significant decrease in TPH content by 87.6%after 6 h of periodic monitoring;breaking down the hydrocarbons into non-toxic environmental friendly products.Kinetics analysis and evaluation shows pseudo-first order mechanism for the Fenton treatment with a calculated rate constant of 0.226 h-1 and half life of 3 h 4 min.The Fenton method is found to be very effective and efficient not only for the removal of the diesel contaminant,but also for the restoration of lost physicochemical properties occasioned by the effect of the contaminant.The environmental friendliness and fast response time towards effective clean up gives the technique a cutting edge advantage over other conventional methods.It therefore presents potentials for remediation experts in outright applications on real field challenges.
文摘The primary aim of this study is inert COD removal from leachate nanofiltration concentrate because of its high concentration of resistant organic pollutants.Within this framework,this study focuses on the treatability of leachate nanofiltration concentrate through Fenton oxidation and optimization of process parameters to reach the maximum pollutant removal by using response surface methodology(RSM).Initial pH,Fe2+concentration,H_(2)O_(2)/Fe^(2+)molar ratio and oxidation time are selected as the independent variables,whereas total COD,color,inert COD and UV254 removal are selected as the responses.According to the ANOVA results,the R^(2) values of all responses are found to be over 95%.Under the optimum conditions determined by the model(pH:3.99,Fe^(2+):150 mmol/L,H_(2)O_(2)/Fe^(2+):3.27 and oxidation time:84.8 min),the maximum COD removal efficiency is determined as 91.4%by the model.The color,inert COD and UV254 removal efficiencies are determined to be 99.9%,97.2%and 99.5%,respectively,by the model,whereas the total COD,color,inert COD and UV254 removal efficiencies are found respectively to be 90%,96.5%,95.3%and 97.2%,experimentally under the optimum operating conditions.The Fenton process improves the biodegradability of the leachate NF concentrate,increasing the BOD5/COD ratio from the value of 0.04 to the value of 0.4.The operational cost of the process is calculated to be 0.238€/g COD_(removed).The results indicate that the Fenton oxidation process is an efficient and economical technology in improvement of the biological degradability of leachate nanofiltration concentrate and in removal of resistant organic pollutants.
基金supported by Key Projects of Natural Science Research in Universities of Anhui Province(No.KJ2018A0409)National Undergraduate Training Programs for Innovation and Entrepreneurship(No.201810375012+1 种基金201810375039)Jiangsu Overseas Visiting Scholar Program for University Prominent Young&Middle-aged Teachers and Presidents。
文摘A new Cu(Ⅱ)coordination polymer,{[Cu3(oba)2(μ^3-OH)2(H2O)2].6H2O}n(H2 oba=4,4’-oxydibenzoic acid),was synthesized by the solvothermal route and characterized by IR,TGA and XRD.The complex crystallizes in the monoclinic system,space group P21/c with a=5.957(6),b=29.746(3),c=9.351(7)A,β=125.709(4)°,V=1345.4(2)A3,Z=2,C28H36Cu3O20,Mr=883.09,Dc=1.913 g/cm^3,F(000)=782,μ=2.427 mm-1,R=0.0780 and wR=0.1688 for 3120 observed reflections with I>2σ(I).The complex forms a 3D framework based on rare infinite rod-shaped secondary building units(SBUs),and C-H…πinteractions play an important role in stabilizing the 3D supramolecular architecture.It shows excellent catalytic activities for the degradation of safranin O(SO)and methylene blue(MB)dyes in aqueous solution under UV light irradiation.Furthermore,the apparent rate constants have also been investigated.
