Removal of nitrophenols （NPs） from aqueous solutions through the adsorption process by using cationic β-cyclodextrin （CCD） modified zeolite （CCDMZ） was investigated. The effects of particle size, contact time, ...Removal of nitrophenols （NPs） from aqueous solutions through the adsorption process by using cationic β-cyclodextrin （CCD） modified zeolite （CCDMZ） was investigated. The effects of particle size, contact time, solution pH values and sodium chloride content in the aqueous on adsorption capacity were evaluated through a series of batch experiments. The results showed that CCDMZ had a higher adsorption capacity for removing NPs at a size fraction of 0.45-0.9 mm while adsorption of NPs on CCDMZ reached equilibrium within 60 min. The adsorption process was apparently influenced by pH values and sodium chloride content in aqueous solution. To ascertain the mechanisms of sorption, the experimental data were modeled by using the pseudo-first and pseudo-second order kinetic equations, and the results indicated that the adsorption kinetics of NPs on CCDMZ well-matched with the pseudo-second order rate expression.展开更多
The adsorption of phenol and nitrophenols on hypercrosslinked polymeric adsorbent was studied as a function of the solution concentration and temperature. Adsorption isotherms of phenol and nitrophenols on hypercrossl...The adsorption of phenol and nitrophenols on hypercrosslinked polymeric adsorbent was studied as a function of the solution concentration and temperature. Adsorption isotherms of phenol and nitrophenols on hypercrosslinked resin were determined. These isotherms were modeled according to the Freundlich adsorption isotherm. The isotherms for phenol and nitrophenols on hypercrosslinked resin were assigned as L curves. Thermodynamic parameters were calculated for all phenol and nitrophenols. The kinetics experiment results showed that the adsorption rates were of the first-order kinetics. The rate constants at 303K were calculated.展开更多
We investigated the biodegradation of 2-nitrophenol （2-NP）, 4-nitrophenol （4-NP）, and 2,4-dinitrophenol （2,4-DNP） in the rhizosphere of Spirodela polyrrhiza plants by conducting degradation experiments with thre...We investigated the biodegradation of 2-nitrophenol （2-NP）, 4-nitrophenol （4-NP）, and 2,4-dinitrophenol （2,4-DNP） in the rhizosphere of Spirodela polyrrhiza plants by conducting degradation experiments with three river water samples supplemented with each nitrophenol （NP）. We then isolated NP-degrading bacteria both from the S. polyrrhiza roots and from the river water. In the river water samples, removal of the three NP was accelerated in the presence of S. polyrrhiza plants. The three NPs persisted in an autoclaved solution with sterile plants suggests that NP removal was accelerated largely by bacterial NP biodegradation rather than by adsorption and uptake by the plants. We isolated 8 strains of NP-degrading bacteria： 6 strains from the S. polyrrhiza roots and 2 strains from river water without the plants. The 2-NP- and 2,4-DNP-degrading bacteria were isolated only from the S. polyrrhiza roots. The 4-NP- degrading bacteria different from those isolated from the river water samples were also found on S. polyrrhiza roots. The 2-NP- and 4-NP-degrading strains isolated from the roots utilized the corresponding NP （0.5 mmol/L） as the sole carbon and energy source. The 2,4-DNP-degrading strains isolated from the roots showed substantial 2,4-DNP-degrading activity, but the presence of other carbon and energy sources was required for their growth. The isolated NP-degrading bacteria from the roots must have contributed to the accelerated degradation of the three NPs in the rhizosphere of S. polyrrhiza. Our results suggested that rhizoremediation with S. polyrrhiza may be effective for NP-contaminated surface water.展开更多
Dihalogenated nitrophenols(2,6-DHNPs),an emerging group of aromatic disinfection byproducts(DBPs)detected in drinking water,have limited available information regarding their persistence and toxicological risks.The pr...Dihalogenated nitrophenols(2,6-DHNPs),an emerging group of aromatic disinfection byproducts(DBPs)detected in drinking water,have limited available information regarding their persistence and toxicological risks.The present study found that 2,6-DHNPs are resistant to major drinking water treatment processes(sedimentation and filtration)and households methods(boiling,filtration,microwave irradiation,and ultrasonic cleaning).To further assess their health risks,we conducted a series of toxicology studies using zebrafish embryos as the model organism.Our findings reveal that these emerging 2,6-DHNPs showed lethal toxicity 248 times greater than that of the regulated DBP,dichloroacetic acid.Specifically,at sublethal concentrations,exposure to 2,6-DHNPs generated reactive oxygen species(ROS),caused apoptosis,inhibited cardiac looping,and induced cardiac failure in zebrafish.Remarkably,the use of a ROS scavenger,N-acetyl-l-cysteine,considerably mitigated these adverse effects,emphasizing the essential role of ROS in 2,6-DHNP-induced cardiotoxicity.Our findings highlight the cardiotoxic potential of 2,6-DHNPs in drinking water even at low concentrations of 19μg/L and the beneficial effect of N-acetyl-l-cysteine in alleviating the 2,6-DHNP-induced cardiotoxicity.This study underscores the urgent need for increased scrutiny of these emerging compounds in public health discussions.展开更多
Nitroaromatic compounds such as nitrobenzene and nitrophenols are largely synthesised and particularly often occur in water bodies as toxic pollutants. The degradation of these compounds in the environment via direct ...Nitroaromatic compounds such as nitrobenzene and nitrophenols are largely synthesised and particularly often occur in water bodies as toxic pollutants. The degradation of these compounds in the environment via direct photolysis and by biological treatment is difficult and usually slow. In our two previous published papers, we have discussed the advanced oxidation of nitrobenzene and nitrophenols in aqueous solutions irradiated by direct photolysis using polychromatic light and by means of UV/H2O2 process. The experimental results suggested the UV/H2O2 process is an effective and efficient technology for complete mineralization of these organic compounds. Based on the results therein, comprehensive reaction mechanism for nitrobenzene photolysis was proposed with detailed discussions.展开更多
The direct photolysis of nitrobenzene and nitrophenols in aqueous solutions irradiated by polychromatic light were investigated. Several aromatic intermediates were identified as three nitrophenol isomers, nitrohydroq...The direct photolysis of nitrobenzene and nitrophenols in aqueous solutions irradiated by polychromatic light were investigated. Several aromatic intermediates were identified as three nitrophenol isomers, nitrohydroquinone, nitrosobenzene, nitrocatechol, catechol and phenol. Nitrite and nitrate ions were also detected in the irradiated solution indicating direct photolysis of nitrobenzene or nitrophenols. The degradation of nitrobenzene and nitrophenols and the formation of three nitrophenol isomers were observed to follow zero-order kinetics. The quantum yields for nitrobenzene and nitrophenols removal are about 10~ -3 and 10~ -3 —10~ -4 respectively. The mechanism for nitrobenzene degradation was suggested to follow mainly nitro-nitrite intramolecular arrangement.展开更多
Photodegradation of nitrobenzene and nitrophenols in aqueous solutions by means of UV/H2 O2 process was studied in the Rayox batch reactors. Three nitrophenol isomers were identified as main photoproducts in the irrad...Photodegradation of nitrobenzene and nitrophenols in aqueous solutions by means of UV/H2 O2 process was studied in the Rayox batch reactors. Three nitrophenol isomers were identified as main photoproducts in the irradiated NB aqueous solutions. The distribution of nitrophenol isomers follows the order p-〉 m-〉 o-nitrophenol. Other intermediates detected include nitrohydroquinone, nitrocatechol, catechol, benzoquinone, phenol, nitrate/nitrite ions, formic acid, glyoxylic acid, maleic acid, oxalic acid and some aliphatic ketones and aldehydes. The degradation of nitrobenzene and nitrophenols at initial stages follows the first-order kinetics and the decay rate constants for nitrobenzene（NB） are around l0^-3-10^-2 s^-1 and for nitrophenols are around 10^-2 s^-1. The decomposition of H2 O2 in the presence of NB and each nitrophenol isomers follows zero-order kinetics. The quantum yields at initial stages for NB decay were estimated around 0.30 to 0.36, and for NPs decay is around 0.31-0.54.展开更多
Lattice‐doping and surface decoration are prospective routes to improve the visible‐light photocatalytic ability of TiO2,but the two techniques are difficult to combine into one preparation process because they are ...Lattice‐doping and surface decoration are prospective routes to improve the visible‐light photocatalytic ability of TiO2,but the two techniques are difficult to combine into one preparation process because they are usually conducted under different conditions,which limits the efficiency of TiO2 modification.In this study,TiO2 was successfully modified by simultaneous lattice‐doping and surface decoration,and the visible‐light photocatalytic capacity was largely improved.Upon comparing the method reported here with previous ones,the most significant difference is that Fe(II)‐phenanthroline was first used as the co‐precursor of the introduced elements of C,N,and Fe.These three elements were simultaneously introduced to TiO2 at high levels by this co‐precursor method.The as‐synthesized photocatalysts were systemically investigated and analyzed by several characterization methods such as XRD,FT‐IR,XPS,Raman spectroscopy,EPR,UV‐Vis DRS,photoluminescence spectra,photocurrent,electrochemical impedance spectra,TEM,and HRTEM.The photocatalytic degradation of 4‐NP under visible‐light irradiation was used to evaluate the photocatalytic activity of the photocatalysts.Based on the experimental data,a probable mechanism for the photocatalytic degradation by the photocatalysts is proposed.This is a novel method of using one source to simultaneously introduce metal and non‐metal elements to TiO2 at high levels,which may provide a new way to prepare highly effective TiO2 photocatalysts.展开更多
A silver-based metal-organic framework（Ag-MOFs）, [Ag2（H3 ddcba）（dpp）2]（1）（H5 ddcba = 3,5-（di（2’,5’-dicarboxylphenyl）benozoic acid, dpp = 1,3-di（4-pyridyl）propane）, was successfully constructed via hyd...A silver-based metal-organic framework（Ag-MOFs）, [Ag2（H3 ddcba）（dpp）2]（1）（H5 ddcba = 3,5-（di（2’,5’-dicarboxylphenyl）benozoic acid, dpp = 1,3-di（4-pyridyl）propane）, was successfully constructed via hydrothermal assembly of a pentacaboxylate ligand, a N-donor ligand and Ag（I） ions, which possesses a pcu topology and exhibits excellent catalytic properties in aqueous solution for the degradation of onitrophenol（2-NP）, m-nitrophenol（3-NP） and p-nitrophenol（4-NP）. Related kinetics of such catalytic reactions, photoluminescent and thermal stability of compound 1 were also investigated.展开更多
Pseudomonas sp. strain WBC-3 utilized methyl parathion or para-nitrophenol (PNP) as the sole source of carbon, nitrogen, and energy, and methyl parathion hydrolase had been previously characterized. Its chemotactic be...Pseudomonas sp. strain WBC-3 utilized methyl parathion or para-nitrophenol (PNP) as the sole source of carbon, nitrogen, and energy, and methyl parathion hydrolase had been previously characterized. Its chemotactic behaviors to aromatics were investigated. The results indicated that strain WBC-3 was attracted to multiple aromatic compounds, including metabolizable or transformable substrates PNP, 4-nitrocatechol, and hydroquinone. Disruption of PNP catabolic genes had no e?ect on its chemotactic behaviors w...展开更多
Abstract A new mixer-settler-mixer three chamber integrated extractor is proposed in this work for liquid-liquid- liquid three phase countercurrent and continuous extraction. Experiments revealed the influences of the...Abstract A new mixer-settler-mixer three chamber integrated extractor is proposed in this work for liquid-liquid- liquid three phase countercurrent and continuous extraction. Experiments revealed the influences of the structural design of the three-liquid-phase extractor and some key operational parameters on three-phase partition of two phenolic isomers, p-nitrophenol （p-NP） and o-nitrophenol （o-NP）. The model three-liquid-phase extraction system used here is nonane （organic top-plaase）-polyethylene glycol （PEG 20UU） （polymer mlddle-phase）-（NH4）2SO4 aqueous solution （aqueous bottom-phase）. It is indicated that agitating speed and retention time in three-phase mixer are key parameters to extraction fraction of nitrophenol. Dispersion band behavior is related to agitating intensity, and its occurrence does not affect the extraction fraction of target compounds. The present work highlights the possibility of a feasible approach of scaling up of the proposed three-phase extraction apparatus for future in- dustrial-aimed applications.展开更多
Kinetic parameters of the decomposition of hazardous chemicals can be applied for the estimation of their thermal behavior under any temperature profile.Presented paper describes the application of the advanced kineti...Kinetic parameters of the decomposition of hazardous chemicals can be applied for the estimation of their thermal behavior under any temperature profile.Presented paper describes the application of the advanced kinetic approach for the determination of the thermal behavior also under adiabatic conditions occurring e.g.in batch reactors in case of cooling failure.The kinetics of the decomposition of different samples(different manufacturers and batches) of 3-methyl-4-nitrophenol were investigated by conventional DSC in non-isothermal(few heating rates varying from 0.25 to 8.0K/min) and isothermal(range of 200~260℃) modes.The kinetic parameters obtained with AKTS-Thermokinetics Software were applied for calculating reaction rate and progress under different heating rates and temperatures and verified by comparing simulated and experimental signals.After application of the heat balance to compare the amount of heat generated during reaction and its removal from the system,the knowledge of reaction rate at any temperature profiles allowed the determination of the temperature increase due to the self-heating in adiabatic and pseudo-adiabatic conditions.Applied advanced kinetic approach allowed simulation the course of the Heat-Wait-Search(HWS) mode of operation of adiabatic calorimeters.The thermal safety diagram depicting dependence of Time to Maximum Rate(TMR) on the initial temperature was calculated and compared with the results of HWS experiments carried out in the system with Ф-factor amounting to 3.2.The influence of the Ф-factor and reaction progress reached at the end of the HWS monitoring on the TMR is discussed.Presented calculations clearly indicate that even very minor reaction progress reduces the TMRad of 24h characteristic for a sample with initial reaction progress amounting to zero.Described estimation method can be verified by just one HWS-ARC,or by one correctly chosen ISO-ARC run of reasonable duration by knowing in advance the dependence of the TMR on the initial temperature for any Ф-factor.Proposed procedure results in significant shortening of the measuring time compared to a safety hazard approach based on series of ARC experiments carried out at the beginning of a process safety evaluation.展开更多
A complex {[Cu（tib）2（H2O）2]·（NO3）2}n（1） has been synthesized under N,N-dimethylacetamide（DMA） and water conditions. The structure of complex 1 was characterized by single-crystal X-ray crystallography. ...A complex {[Cu（tib）2（H2O）2]·（NO3）2}n（1） has been synthesized under N,N-dimethylacetamide（DMA） and water conditions. The structure of complex 1 was characterized by single-crystal X-ray crystallography. It crystallizes in monoclinic, space group P21/n with a = 10.6273（7）, b = 11.4184（7）, c = 13.4215（8） A, β = 108.290（2）°, V = 1546.38（17）A3, Z = 2, F（000） = 798, Dc = 1.667 g/cm3 and m = 0.786 mm-1） Complex 1 exhibits a 3D network due to the existence of O–H…O interaction between coordinated water and nitrate anions. Furthermore, complex 1 has a good catalytic activity for the reduction of 4-nitrophenol in Na BH4 solution.展开更多
A single adsorption isothermal study was performed over HY and BEA zeolites in order to determine their adsorption capacities for phenol, ortho-nitrophenol and para-nitrophenol. The experiments were realized in batch ...A single adsorption isothermal study was performed over HY and BEA zeolites in order to determine their adsorption capacities for phenol, ortho-nitrophenol and para-nitrophenol. The experiments were realized in batch reactor and the isotherms were modelized by the Fowler-Guggenheim equation. During the adsorption process weak zeolite-sorbate interactions and more significant sorbate-sorbate attractions were identified. The adsorption was not linked to the molecular size of the sorbates and a strong correlation was established between the adsorption compound was the best adsorbed. The removal performances capacities and the dipole moments of the sorbates. The most polar of the zeolites depended on their hydrophobicity.展开更多
Nanoscale zero-valent iron(n ZVI) particles supported on a porous, semi-interpenetrating(semi-IPN), temperature-sensitive composite hydrogel(PNIPAm-PHEMA). n ZVI@PNIPAmPHEMA, was successfully synthesized and character...Nanoscale zero-valent iron(n ZVI) particles supported on a porous, semi-interpenetrating(semi-IPN), temperature-sensitive composite hydrogel(PNIPAm-PHEMA). n ZVI@PNIPAmPHEMA, was successfully synthesized and characterized by FT-IR, SEM, EDS, XRD and the weighing method. The loading of nZVI was 0.1548 ± 0.0015 g/g and the particle size was30–100 nm. NZVI was uniformly dispersed on the pore walls inside the PNIPAm-PHEMA.Because of the well-dispersed n ZVI, the highly porous structure, and the synergistic effect of PNIPAm-PHEMA, nZVI@PNIPAm-PHEMA showed excellent reductive activity and wide p H applicability. 95% of 4-NP in 100 m L of 400 mg/L 4-NP solution with initial p H 3.0–9.0 could be completely reduced into 4-AP by about 0.0548 g of fresh supported n ZVI at 18–25 °C under stirring(110 r/min) within 45 min reaction time. A greater than 99% 4-NP degradation ratio was obtained when the initial p H was 5.0–9.0. The reduction of 4-NP by nZVI@PNIPAm-PHEMA was in agreement with the pseudo-first-order kinetics model with Kobsvalues of 0.0885–0.101 min-1.NZVI@PNIPAm-PHEMA was able to be recycled, and about 85% degradation ratio of 4-NP was obtained after its sixth reuse cycle. According to the temperature sensitivity of PNIPAmPHEMA, n ZVI@PNIPAm-PHEMA exhibited very good storage stability, and about 88.9%degradation ratio of 4-NP was obtained after its storage for 30 days. The hybrid reducer was highly efficient for the reduction of 2-NP, 3-NP, 2-chloro-4-nitrophenol and 2-chloro-4-nitrophenol. Our results suggest that PNIPAm-PHEMA could be a good potential carrier, with n ZVI@PNIPAm-PHEMA having potential value in the application of reductive degradation of nitrophenol pollutants.展开更多
Horseradish peroxidase, an acidic peroxidase from the horseradish, is one of the most important enzymes as analytical reagent. The enzymatic nitration of phenol by oxidation of nitrite was studied using horseradish pe...Horseradish peroxidase, an acidic peroxidase from the horseradish, is one of the most important enzymes as analytical reagent. The enzymatic nitration of phenol by oxidation of nitrite was studied using horseradish peroxidase in the presence of H2O2. The results showed that nitration occur at 2- and 4- positions of phenol. There were also minor products of hydroquinone and catechol. The influence of various reaction parameters, including pH, organic solvent, and concentration of H2O2, on nitration products were discussed. The best nitration pH was 7.0, and H2O2 should be added to the reaction mixture slowly.展开更多
This paper presents experimental study on six carbonaceous industrial waste samples that were obtained from a local industry in Saskatchewan, Canada. Hereafter, the samples are coded as ES1, ES2, ES3, PU, RPS and SS1 ...This paper presents experimental study on six carbonaceous industrial waste samples that were obtained from a local industry in Saskatchewan, Canada. Hereafter, the samples are coded as ES1, ES2, ES3, PU, RPS and SS1 and were characterized using IR and 13C solid state NMR spectroscopy, nitrogen porosimetry, TGA, metal leaching analysis using ICP and point-of-zero-charge. Adsorption studies were conducted using two types of adsorptive dye probes (p-nitrophenol, PNP;and methylene blue;MB) at pH 4.60 and pH 7.00.展开更多
p nitrophenol is synthesized using p nitrochlorobenzene and sodium hydroxide with phase transfer catalyst. Several reaction factors, such as catalyst type, the amounts of catalysts and sodium hydroxide, the concentrat...p nitrophenol is synthesized using p nitrochlorobenzene and sodium hydroxide with phase transfer catalyst. Several reaction factors, such as catalyst type, the amounts of catalysts and sodium hydroxide, the concentration of sodium hydroxide solution as well as reaction time, affect greatly the yield of p nitrophenol. The optimum reaction conditions are as follows: A 1 used as phase transfer catalyst whose consumption is 6% (mole fraction) of p nitrochlorobenzene; the molar ratio of sodium hydroxide to p nitrochlorobenzene is 3:1; the concentration of sodium hydroxide solution is 50% (mass fraction). Nitrobenzene, whose molar amount is 2.45 times as much as that of p nitrochlorobenzene; reaction time is 7 h at 140 ℃ under normal pressure. The final yield of p nitrophenol is 83.6%.展开更多
Based on the molecular recognition ability of conductive polymer and the peculiar properties of carbon nanotubes,a novel single wall nanotubes(SWNTs)compound poly(4-aminopyridine)modified electrode(SWNTs/POAPE)is prep...Based on the molecular recognition ability of conductive polymer and the peculiar properties of carbon nanotubes,a novel single wall nanotubes(SWNTs)compound poly(4-aminopyridine)modified electrode(SWNTs/POAPE)is prepared at glass carbon electrode(GCE).The electrochemistry response of nitrophenol isomers is studied at the SWNTs/POAPE.The re-sult indicates that o-,m-and p-nitrophenol are separated entirely at the SWNTs/POAPE interface.The electrode present here can be easily used to determine nitrophenol isomers simultaneously with higher sensitivity.展开更多
基金Supported by the National Natural Science Foundation of China （NEPCP 200809098） and the Natural Science Foundation ot Gansu Province （0803RJZA003）.
文摘Removal of nitrophenols （NPs） from aqueous solutions through the adsorption process by using cationic β-cyclodextrin （CCD） modified zeolite （CCDMZ） was investigated. The effects of particle size, contact time, solution pH values and sodium chloride content in the aqueous on adsorption capacity were evaluated through a series of batch experiments. The results showed that CCDMZ had a higher adsorption capacity for removing NPs at a size fraction of 0.45-0.9 mm while adsorption of NPs on CCDMZ reached equilibrium within 60 min. The adsorption process was apparently influenced by pH values and sodium chloride content in aqueous solution. To ascertain the mechanisms of sorption, the experimental data were modeled by using the pseudo-first and pseudo-second order kinetic equations, and the results indicated that the adsorption kinetics of NPs on CCDMZ well-matched with the pseudo-second order rate expression.
文摘The adsorption of phenol and nitrophenols on hypercrosslinked polymeric adsorbent was studied as a function of the solution concentration and temperature. Adsorption isotherms of phenol and nitrophenols on hypercrosslinked resin were determined. These isotherms were modeled according to the Freundlich adsorption isotherm. The isotherms for phenol and nitrophenols on hypercrosslinked resin were assigned as L curves. Thermodynamic parameters were calculated for all phenol and nitrophenols. The kinetics experiment results showed that the adsorption rates were of the first-order kinetics. The rate constants at 303K were calculated.
基金supported by Japan Science and Technology Agency (JST)the National Natural Science Foundation of China (NSFC) Project as the Japan-China Joint Research Program on Science and Technology (S&T) for Environmental Conservation and Construction of a Society with Less Environmental Burden with the research theme of Development of remediation technique for water environmental pollution using microorganisms and aquatic plants with purification ability-enhanced rhizosphere
文摘We investigated the biodegradation of 2-nitrophenol （2-NP）, 4-nitrophenol （4-NP）, and 2,4-dinitrophenol （2,4-DNP） in the rhizosphere of Spirodela polyrrhiza plants by conducting degradation experiments with three river water samples supplemented with each nitrophenol （NP）. We then isolated NP-degrading bacteria both from the S. polyrrhiza roots and from the river water. In the river water samples, removal of the three NP was accelerated in the presence of S. polyrrhiza plants. The three NPs persisted in an autoclaved solution with sterile plants suggests that NP removal was accelerated largely by bacterial NP biodegradation rather than by adsorption and uptake by the plants. We isolated 8 strains of NP-degrading bacteria： 6 strains from the S. polyrrhiza roots and 2 strains from river water without the plants. The 2-NP- and 2,4-DNP-degrading bacteria were isolated only from the S. polyrrhiza roots. The 4-NP- degrading bacteria different from those isolated from the river water samples were also found on S. polyrrhiza roots. The 2-NP- and 4-NP-degrading strains isolated from the roots utilized the corresponding NP （0.5 mmol/L） as the sole carbon and energy source. The 2,4-DNP-degrading strains isolated from the roots showed substantial 2,4-DNP-degrading activity, but the presence of other carbon and energy sources was required for their growth. The isolated NP-degrading bacteria from the roots must have contributed to the accelerated degradation of the three NPs in the rhizosphere of S. polyrrhiza. Our results suggested that rhizoremediation with S. polyrrhiza may be effective for NP-contaminated surface water.
基金supported by Jinhua Public Welfare Technology Application Research Project(2022-4-046)the Open Fund Project of Key Laboratory of Watershed Earth Surface Processes and Ecological Security of Zhejiang Normal University(KF-2022-15)+2 种基金the Foundation Natural Science Foundation of Zhejiang Province(LQ21D010008)the University of Pittsburgh Momentum Funds 2022-23(006068)the University of Pittsburgh Competitive Medical Research Fund 2023-24(006559).
文摘Dihalogenated nitrophenols(2,6-DHNPs),an emerging group of aromatic disinfection byproducts(DBPs)detected in drinking water,have limited available information regarding their persistence and toxicological risks.The present study found that 2,6-DHNPs are resistant to major drinking water treatment processes(sedimentation and filtration)and households methods(boiling,filtration,microwave irradiation,and ultrasonic cleaning).To further assess their health risks,we conducted a series of toxicology studies using zebrafish embryos as the model organism.Our findings reveal that these emerging 2,6-DHNPs showed lethal toxicity 248 times greater than that of the regulated DBP,dichloroacetic acid.Specifically,at sublethal concentrations,exposure to 2,6-DHNPs generated reactive oxygen species(ROS),caused apoptosis,inhibited cardiac looping,and induced cardiac failure in zebrafish.Remarkably,the use of a ROS scavenger,N-acetyl-l-cysteine,considerably mitigated these adverse effects,emphasizing the essential role of ROS in 2,6-DHNP-induced cardiotoxicity.Our findings highlight the cardiotoxic potential of 2,6-DHNPs in drinking water even at low concentrations of 19μg/L and the beneficial effect of N-acetyl-l-cysteine in alleviating the 2,6-DHNP-induced cardiotoxicity.This study underscores the urgent need for increased scrutiny of these emerging compounds in public health discussions.
文摘Nitroaromatic compounds such as nitrobenzene and nitrophenols are largely synthesised and particularly often occur in water bodies as toxic pollutants. The degradation of these compounds in the environment via direct photolysis and by biological treatment is difficult and usually slow. In our two previous published papers, we have discussed the advanced oxidation of nitrobenzene and nitrophenols in aqueous solutions irradiated by direct photolysis using polychromatic light and by means of UV/H2O2 process. The experimental results suggested the UV/H2O2 process is an effective and efficient technology for complete mineralization of these organic compounds. Based on the results therein, comprehensive reaction mechanism for nitrobenzene photolysis was proposed with detailed discussions.
文摘The direct photolysis of nitrobenzene and nitrophenols in aqueous solutions irradiated by polychromatic light were investigated. Several aromatic intermediates were identified as three nitrophenol isomers, nitrohydroquinone, nitrosobenzene, nitrocatechol, catechol and phenol. Nitrite and nitrate ions were also detected in the irradiated solution indicating direct photolysis of nitrobenzene or nitrophenols. The degradation of nitrobenzene and nitrophenols and the formation of three nitrophenol isomers were observed to follow zero-order kinetics. The quantum yields for nitrobenzene and nitrophenols removal are about 10~ -3 and 10~ -3 —10~ -4 respectively. The mechanism for nitrobenzene degradation was suggested to follow mainly nitro-nitrite intramolecular arrangement.
文摘Photodegradation of nitrobenzene and nitrophenols in aqueous solutions by means of UV/H2 O2 process was studied in the Rayox batch reactors. Three nitrophenol isomers were identified as main photoproducts in the irradiated NB aqueous solutions. The distribution of nitrophenol isomers follows the order p-〉 m-〉 o-nitrophenol. Other intermediates detected include nitrohydroquinone, nitrocatechol, catechol, benzoquinone, phenol, nitrate/nitrite ions, formic acid, glyoxylic acid, maleic acid, oxalic acid and some aliphatic ketones and aldehydes. The degradation of nitrobenzene and nitrophenols at initial stages follows the first-order kinetics and the decay rate constants for nitrobenzene（NB） are around l0^-3-10^-2 s^-1 and for nitrophenols are around 10^-2 s^-1. The decomposition of H2 O2 in the presence of NB and each nitrophenol isomers follows zero-order kinetics. The quantum yields at initial stages for NB decay were estimated around 0.30 to 0.36, and for NPs decay is around 0.31-0.54.
基金supported by the National Natural Science Foundation of China(51368044,51568051,51668046)the National Science Fund for Excellent Young Scholars(51422807)+6 种基金the Science and Technology Supporting Program of Jiangxi Province(20151BBG70018)the Natural Science Foundation of Jiangxi Province for Distinguished Young Scholars(20162BCB23041)the Science Foundation for Young Scientists of Jiangxi Province-Key Project(20171ACB21034)the Science and Technology Project of Jiangxi Provincial Education Department(GJJ160700)the Natural Science Foundation of Jiangxi Province(20161BAB216102)the Jiangxi Province Educational Reform Project(JXJG-16-8-7)the Nanchang Hangkong University Educational Reform Project(JY1604,JY1605,KCPY-1511)~~
文摘Lattice‐doping and surface decoration are prospective routes to improve the visible‐light photocatalytic ability of TiO2,but the two techniques are difficult to combine into one preparation process because they are usually conducted under different conditions,which limits the efficiency of TiO2 modification.In this study,TiO2 was successfully modified by simultaneous lattice‐doping and surface decoration,and the visible‐light photocatalytic capacity was largely improved.Upon comparing the method reported here with previous ones,the most significant difference is that Fe(II)‐phenanthroline was first used as the co‐precursor of the introduced elements of C,N,and Fe.These three elements were simultaneously introduced to TiO2 at high levels by this co‐precursor method.The as‐synthesized photocatalysts were systemically investigated and analyzed by several characterization methods such as XRD,FT‐IR,XPS,Raman spectroscopy,EPR,UV‐Vis DRS,photoluminescence spectra,photocurrent,electrochemical impedance spectra,TEM,and HRTEM.The photocatalytic degradation of 4‐NP under visible‐light irradiation was used to evaluate the photocatalytic activity of the photocatalysts.Based on the experimental data,a probable mechanism for the photocatalytic degradation by the photocatalysts is proposed.This is a novel method of using one source to simultaneously introduce metal and non‐metal elements to TiO2 at high levels,which may provide a new way to prepare highly effective TiO2 photocatalysts.
基金financial support from the National Science Foundation of China (Nos. 216731272, 2137312, 21671119, 51572152 and 51502155)
文摘A silver-based metal-organic framework（Ag-MOFs）, [Ag2（H3 ddcba）（dpp）2]（1）（H5 ddcba = 3,5-（di（2’,5’-dicarboxylphenyl）benozoic acid, dpp = 1,3-di（4-pyridyl）propane）, was successfully constructed via hydrothermal assembly of a pentacaboxylate ligand, a N-donor ligand and Ag（I） ions, which possesses a pcu topology and exhibits excellent catalytic properties in aqueous solution for the degradation of onitrophenol（2-NP）, m-nitrophenol（3-NP） and p-nitrophenol（4-NP）. Related kinetics of such catalytic reactions, photoluminescent and thermal stability of compound 1 were also investigated.
基金the Hi-Tech Research and Development Program (863) of China (No.2006AA10Z403)the Knowledge Innovation Program ofthe Chinese Academy of Sciences (No. KSCX2-YW-G-009)the National Natural Science Foundation ofChina (No. 30570021)
文摘Pseudomonas sp. strain WBC-3 utilized methyl parathion or para-nitrophenol (PNP) as the sole source of carbon, nitrogen, and energy, and methyl parathion hydrolase had been previously characterized. Its chemotactic behaviors to aromatics were investigated. The results indicated that strain WBC-3 was attracted to multiple aromatic compounds, including metabolizable or transformable substrates PNP, 4-nitrocatechol, and hydroquinone. Disruption of PNP catabolic genes had no e?ect on its chemotactic behaviors w...
基金Supported by the National Natural Science Foundation of China (51074150,21027004)the National Basic Research Program of China (2012CBA01203,2007CB613507)the Innovative Research Group Science Fund (20221603)
文摘Abstract A new mixer-settler-mixer three chamber integrated extractor is proposed in this work for liquid-liquid- liquid three phase countercurrent and continuous extraction. Experiments revealed the influences of the structural design of the three-liquid-phase extractor and some key operational parameters on three-phase partition of two phenolic isomers, p-nitrophenol （p-NP） and o-nitrophenol （o-NP）. The model three-liquid-phase extraction system used here is nonane （organic top-plaase）-polyethylene glycol （PEG 20UU） （polymer mlddle-phase）-（NH4）2SO4 aqueous solution （aqueous bottom-phase）. It is indicated that agitating speed and retention time in three-phase mixer are key parameters to extraction fraction of nitrophenol. Dispersion band behavior is related to agitating intensity, and its occurrence does not affect the extraction fraction of target compounds. The present work highlights the possibility of a feasible approach of scaling up of the proposed three-phase extraction apparatus for future in- dustrial-aimed applications.
文摘Kinetic parameters of the decomposition of hazardous chemicals can be applied for the estimation of their thermal behavior under any temperature profile.Presented paper describes the application of the advanced kinetic approach for the determination of the thermal behavior also under adiabatic conditions occurring e.g.in batch reactors in case of cooling failure.The kinetics of the decomposition of different samples(different manufacturers and batches) of 3-methyl-4-nitrophenol were investigated by conventional DSC in non-isothermal(few heating rates varying from 0.25 to 8.0K/min) and isothermal(range of 200~260℃) modes.The kinetic parameters obtained with AKTS-Thermokinetics Software were applied for calculating reaction rate and progress under different heating rates and temperatures and verified by comparing simulated and experimental signals.After application of the heat balance to compare the amount of heat generated during reaction and its removal from the system,the knowledge of reaction rate at any temperature profiles allowed the determination of the temperature increase due to the self-heating in adiabatic and pseudo-adiabatic conditions.Applied advanced kinetic approach allowed simulation the course of the Heat-Wait-Search(HWS) mode of operation of adiabatic calorimeters.The thermal safety diagram depicting dependence of Time to Maximum Rate(TMR) on the initial temperature was calculated and compared with the results of HWS experiments carried out in the system with Ф-factor amounting to 3.2.The influence of the Ф-factor and reaction progress reached at the end of the HWS monitoring on the TMR is discussed.Presented calculations clearly indicate that even very minor reaction progress reduces the TMRad of 24h characteristic for a sample with initial reaction progress amounting to zero.Described estimation method can be verified by just one HWS-ARC,or by one correctly chosen ISO-ARC run of reasonable duration by knowing in advance the dependence of the TMR on the initial temperature for any Ф-factor.Proposed procedure results in significant shortening of the measuring time compared to a safety hazard approach based on series of ARC experiments carried out at the beginning of a process safety evaluation.
基金Supported by the National Natural Science foundation of China(21301005,21671004,51404006)Natural Science Foundation of Anhui Province(1408085QB31)the open fund of Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control(KFK201508)
文摘A complex {[Cu（tib）2（H2O）2]·（NO3）2}n（1） has been synthesized under N,N-dimethylacetamide（DMA） and water conditions. The structure of complex 1 was characterized by single-crystal X-ray crystallography. It crystallizes in monoclinic, space group P21/n with a = 10.6273（7）, b = 11.4184（7）, c = 13.4215（8） A, β = 108.290（2）°, V = 1546.38（17）A3, Z = 2, F（000） = 798, Dc = 1.667 g/cm3 and m = 0.786 mm-1） Complex 1 exhibits a 3D network due to the existence of O–H…O interaction between coordinated water and nitrate anions. Furthermore, complex 1 has a good catalytic activity for the reduction of 4-nitrophenol in Na BH4 solution.
文摘A single adsorption isothermal study was performed over HY and BEA zeolites in order to determine their adsorption capacities for phenol, ortho-nitrophenol and para-nitrophenol. The experiments were realized in batch reactor and the isotherms were modelized by the Fowler-Guggenheim equation. During the adsorption process weak zeolite-sorbate interactions and more significant sorbate-sorbate attractions were identified. The adsorption was not linked to the molecular size of the sorbates and a strong correlation was established between the adsorption compound was the best adsorbed. The removal performances capacities and the dipole moments of the sorbates. The most polar of the zeolites depended on their hydrophobicity.
基金supported by the National Natural Science Foundation of China(No.51508233)the Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment
文摘Nanoscale zero-valent iron(n ZVI) particles supported on a porous, semi-interpenetrating(semi-IPN), temperature-sensitive composite hydrogel(PNIPAm-PHEMA). n ZVI@PNIPAmPHEMA, was successfully synthesized and characterized by FT-IR, SEM, EDS, XRD and the weighing method. The loading of nZVI was 0.1548 ± 0.0015 g/g and the particle size was30–100 nm. NZVI was uniformly dispersed on the pore walls inside the PNIPAm-PHEMA.Because of the well-dispersed n ZVI, the highly porous structure, and the synergistic effect of PNIPAm-PHEMA, nZVI@PNIPAm-PHEMA showed excellent reductive activity and wide p H applicability. 95% of 4-NP in 100 m L of 400 mg/L 4-NP solution with initial p H 3.0–9.0 could be completely reduced into 4-AP by about 0.0548 g of fresh supported n ZVI at 18–25 °C under stirring(110 r/min) within 45 min reaction time. A greater than 99% 4-NP degradation ratio was obtained when the initial p H was 5.0–9.0. The reduction of 4-NP by nZVI@PNIPAm-PHEMA was in agreement with the pseudo-first-order kinetics model with Kobsvalues of 0.0885–0.101 min-1.NZVI@PNIPAm-PHEMA was able to be recycled, and about 85% degradation ratio of 4-NP was obtained after its sixth reuse cycle. According to the temperature sensitivity of PNIPAmPHEMA, n ZVI@PNIPAm-PHEMA exhibited very good storage stability, and about 88.9%degradation ratio of 4-NP was obtained after its storage for 30 days. The hybrid reducer was highly efficient for the reduction of 2-NP, 3-NP, 2-chloro-4-nitrophenol and 2-chloro-4-nitrophenol. Our results suggest that PNIPAm-PHEMA could be a good potential carrier, with n ZVI@PNIPAm-PHEMA having potential value in the application of reductive degradation of nitrophenol pollutants.
文摘Horseradish peroxidase, an acidic peroxidase from the horseradish, is one of the most important enzymes as analytical reagent. The enzymatic nitration of phenol by oxidation of nitrite was studied using horseradish peroxidase in the presence of H2O2. The results showed that nitration occur at 2- and 4- positions of phenol. There were also minor products of hydroquinone and catechol. The influence of various reaction parameters, including pH, organic solvent, and concentration of H2O2, on nitration products were discussed. The best nitration pH was 7.0, and H2O2 should be added to the reaction mixture slowly.
文摘This paper presents experimental study on six carbonaceous industrial waste samples that were obtained from a local industry in Saskatchewan, Canada. Hereafter, the samples are coded as ES1, ES2, ES3, PU, RPS and SS1 and were characterized using IR and 13C solid state NMR spectroscopy, nitrogen porosimetry, TGA, metal leaching analysis using ICP and point-of-zero-charge. Adsorption studies were conducted using two types of adsorptive dye probes (p-nitrophenol, PNP;and methylene blue;MB) at pH 4.60 and pH 7.00.
文摘p nitrophenol is synthesized using p nitrochlorobenzene and sodium hydroxide with phase transfer catalyst. Several reaction factors, such as catalyst type, the amounts of catalysts and sodium hydroxide, the concentration of sodium hydroxide solution as well as reaction time, affect greatly the yield of p nitrophenol. The optimum reaction conditions are as follows: A 1 used as phase transfer catalyst whose consumption is 6% (mole fraction) of p nitrochlorobenzene; the molar ratio of sodium hydroxide to p nitrochlorobenzene is 3:1; the concentration of sodium hydroxide solution is 50% (mass fraction). Nitrobenzene, whose molar amount is 2.45 times as much as that of p nitrochlorobenzene; reaction time is 7 h at 140 ℃ under normal pressure. The final yield of p nitrophenol is 83.6%.
基金the Natural Science Foundation of Henan Province,China(Grant No.0311021000)the Key Laboratory of Environmental Science and Engineering,Education Commission of Henan Province.
文摘Based on the molecular recognition ability of conductive polymer and the peculiar properties of carbon nanotubes,a novel single wall nanotubes(SWNTs)compound poly(4-aminopyridine)modified electrode(SWNTs/POAPE)is prepared at glass carbon electrode(GCE).The electrochemistry response of nitrophenol isomers is studied at the SWNTs/POAPE.The re-sult indicates that o-,m-and p-nitrophenol are separated entirely at the SWNTs/POAPE interface.The electrode present here can be easily used to determine nitrophenol isomers simultaneously with higher sensitivity.
