This study surveyed 180 samples of ultra high temperature （UHT） milk of four top Chinese dairy brands collected in the 25 cities in China in June 2011, and assessed their contamination with antibiotics, using the EL...This study surveyed 180 samples of ultra high temperature （UHT） milk of four top Chinese dairy brands collected in the 25 cities in China in June 2011, and assessed their contamination with antibiotics, using the ELISA method. The percentages of tetracyclines, sulfonamides, sulfamethazine, and quinolones detected in the samples were 0, 16.7, 40.6, and 100%, respectively. The maximum concentrations of the tetracyclines, sulfonamides, sulfamethazine and quinolones in UHT milk samples were 〈1.5, 26.2, 22.6, and 58.8 μg kg-1, respectively. None of the samples exceeded the maximum residue levels （MRLs） for these four veterinary drugs, according to the regulations set by China, the European Union （EU） and the Codex Alimentarius Commission （CAC）.展开更多
Intensive use of sulfamethazine(SM_2) in aquaculture has resulted in some detrimental effects to non-targeted organisms. In order to assess its potential ecological risk, it is crucial to have a good understanding on ...Intensive use of sulfamethazine(SM_2) in aquaculture has resulted in some detrimental effects to non-targeted organisms. In order to assess its potential ecological risk, it is crucial to have a good understanding on the bioaccumulation and biodegradation of SM_2 in Chlorella pyrenoidosa. The microalgae were treated with 2, 4, and 8 mg L^(-1) of sulfamethazine for 13 days, respectively, showing that the inhibition effects of sulfamethazine on the growth of Chlorella pyrenoidosa increased progressively as the concentrations of sulfamethazine increasing from 2 to 8 mg L^(-1). The peak concentrations of sulfamethazine accumulated in C. pyrenoidosa were 0.225, 0.325, and 0.596 ng per mg FW on day 13 for three treatment groups, respectively, showing a great ability to deplete sulfamethazine from the culture media. On day 13, the percentages of biotic degradation were 48.45%, 60.21% and 69.93%, respectively. The EC_(50) of 10.05 mg L^(-1) was derived which showed no significant risk for C. pyrenoidosa with a calculated risk quotient < 1. The activities of superoxide dismutase and catalase increased progressively in response to sulfamethazine and showed a positive correlation to the treatment concentrations. The highest superoxide dismutase activity was achieved at the concentration of 8 mg L^(-1) after 2 d of exposure, which was 1.89 folds higher than that of the control. The activity of catalase has a similar pattern to that of superoxide dismutase with the maximum activity achieved at day 2, which was 3.11 folds higher compared to that of the control. In contrast to superoxide dismutase and catalase, the maximum glutathione S-transferase activity was observed at day 6, showing 2.2 folds higher than that of the control.展开更多
In the present study,zinc molybdate(β‐ZnMoO4)and graphitic carbon nitride(g‐C3N4)‐modifiedβ‐ZnMoO4(β‐ZnMoO4/g‐C3N4)were prepared to decontaminate aqueous solutions from the antibiotic sulfamethazine(SMZ).Our ...In the present study,zinc molybdate(β‐ZnMoO4)and graphitic carbon nitride(g‐C3N4)‐modifiedβ‐ZnMoO4(β‐ZnMoO4/g‐C3N4)were prepared to decontaminate aqueous solutions from the antibiotic sulfamethazine(SMZ).Our results revealed that the hydrothermal synthesis method greatly influenced the photocatalytic activity of the resultant catalysts.The pristineβ‐ZnMoO4samples obtained under more intensive synthesis conditions(24h at280°C)showed higher photocatalytic activity than that prepared for12h at180°C(denotedβ‐ZnMoO4‐180).In the case of in situ hydrothermal synthesis ofβ‐ZnMoO4/g‐C3N4,a surface‐modified sample was only obtained under the reaction conditions of180°C for12h.Compared with the sheet‐likeβ‐ZnMoO4‐180sample,theβ‐ZnMoO4‐180/g‐C3N4composite showed enhanced photocatalytic activity for the degradation of SMZ.By contrast,the hydrothermal reaction at280°C caused the gradual decomposition of g‐C3N4.It is believed that the structural incorporation of g‐C3N4intoβ‐ZnMoO4at280°C might disrupt the crystal growth,thereby deteriorating the performance of the composite catalysts formed at this temperature.For the composite catalysts prepared by the ultrasonic method,a remarkable increase in the degradation rate of SMZ was only observed at a high g‐C3N4content of8mol%.The photocatalytic degradation of SMZ byβ‐ZnMoO4‐180/g‐C3N4composite catalysts followed pseudo‐first‐order kinetics.Further study of the photocatalytic mechanism revealed that holes and superoxide radicals were the dominant oxidative species in the photodegradation process.The enhanced photocatalytic performance of the composites was attributed to the higher separation efficiency of the photogenerated electron‐hole pairs at heterogeneous junctions.The degradation intermediates of SMZ were detected by liquid chromatography‐mass spectrometry,from which plausible reaction pathways for the photodegradation of SMZ were proposed.Our results indicated that the synthesis method for g‐C3N4composites should be carefully selected to achieve superior photocatalytic performance.展开更多
Two artificial antigens were synthesized successfully by diazotizing method, sulfamethazine（SM2）-human serum albumin （HSA） was used for the immunogen, and SM2-ovalbumin（OVA） was used for the coating antigen. The...Two artificial antigens were synthesized successfully by diazotizing method, sulfamethazine（SM2）-human serum albumin （HSA） was used for the immunogen, and SM2-ovalbumin（OVA） was used for the coating antigen. The coupled reaction was successful by confirmation of the ultraviolet scanning spectrometer, and the conjugation ratio of SM2 with HSA and OVA was 9：1 and 15：1, respectively. Using cell-fusion and limiting dilution method to reclone 5 times to get 3 hybridoma strains, which could stably secret monoclonal antibody （Mab）, named CBT, BC4 and BB12. The subtype of BC4 Mab was IgG1 and chain, the molecular weight was 162 ku, the numbers of chromosomal were about 90, the affinity constant was 6.1 × 10^12 M^-1. No cross reactivity was seen between the Mab and the other 4 sulfonamides, as well as the 2 carries proteins. The Mab antibody had excellent stability.展开更多
Sorption mechanisms of sulfamethazine(SMT)in different pH solutions are complicated.It has not been sufficiently investigated to enhance removal of SMT from alkalescent aqueous solution.In this study,sorption isotherm...Sorption mechanisms of sulfamethazine(SMT)in different pH solutions are complicated.It has not been sufficiently investigated to enhance removal of SMT from alkalescent aqueous solution.In this study,sorption isotherms and kinetics of SMT by corn biochars pyrolyzed at 300℃ and 600℃(300C,600C)under diverse pH conditions were compared.In order to improve the sorption efficiency of SMT from alkalescent aqueous solution,the biochar 300C was modified by acid or base.Different mathematic models were used to describe sorption driving force and sorption process.Results showed that the biochar 300C possessed more amorphous organic carbon and polar functional groups,which led to a higher sorption capacity than biochar 600C.The sorption rate of biochar 300C was greater than 600C under diverse pH as the physisorption of 300C outweighed 600C.The SMT presented stronger hydrophobicity at pH 5 and higher electrostatic repulsion at pH 1 or 8,which resulted in a higher combining capacity of SMT with both biochars at pH 5 than other pH values.In addition,the acid modified biochar had better removal effect on SMT than alkali at pH solution around 8.The research provides a theoretical basis for the removal of SMT from alkalescent aqueous solution.展开更多
A homemade array surface plasmon resonance （SPR）-based imaging biosensor was used to develop sensitive and fast immunoassays to determine sulfamethoxazole （SMOZ） and sulfamethazine （SMT） in buffer. Two conjugati...A homemade array surface plasmon resonance （SPR）-based imaging biosensor was used to develop sensitive and fast immunoassays to determine sulfamethoxazole （SMOZ） and sulfamethazine （SMT） in buffer. Two conjugations of sulfonamide-bovine serum albumin （BSA） were separately immobilized on two different rows of the array chip with one row as reference. The immobilization was carried out in the instrument to monitor the quantity of the conjugations immobilized. The antibody mixed with the sulfonamide in the buffer was injected over the surface of the chip to get a relative response which was inversely proportional to the concentration of the sulfonamide in the PBS buffer. Two calibration curves were constructed and the limit of detection for sufamethoxazole in buffer was 3.5 ng/mL and for sulfamethazine 0.6 ng/mL. The stability and specificity of the antibody were also studied. The monoclonal antibody did not bind with BSA.展开更多
In this study, various factors of ELISA for detection of sulfamethazine residues were explored, the coating antigen was diluted to 1：400, the best coating condition was at 4℃ overnight, the working concentration of ...In this study, various factors of ELISA for detection of sulfamethazine residues were explored, the coating antigen was diluted to 1：400, the best coating condition was at 4℃ overnight, the working concentration of HRP-IgG enzyme conjugate was 1 ： 7 000. The pre-incubation time and incubation time was 30 min and 120 min, respectively, the substrate solution working time was 20 min. Two moL · L^-1 H2SO4 was used to stop the reaction and checked. A standard curve of direct competitive ELISA had been established to detect the sulfamethazine residues in milk. The detection limit of this method was 1.97 ng · mL^-1. The mean concentration of sulfamethazine required to inhibit 30% antibody was 7.1 ng · mL^-1. The linear range of the detection was 5-200 ng · mL^-1. The recovery ratio was between 73.20% and 91.16%. The CV% of within array and between arrays was less than 10%.展开更多
In this work,boron(B)was used to promote Fe^(3+)/peracetic acid(Fe^(3+)/PAA)for the degradation of sulfamethazine(SMT).An SMT degradation efficiency of 9.1%was observed in the Fe^(3+)/PAA system over 60 min,which was ...In this work,boron(B)was used to promote Fe^(3+)/peracetic acid(Fe^(3+)/PAA)for the degradation of sulfamethazine(SMT).An SMT degradation efficiency of 9.1%was observed in the Fe^(3+)/PAA system over 60 min,which was significantly increased to 99.3%in the B/Fe^(3+)/PAA system over 10 min.The B/Fe^(3+)/PAA process also exhibited superior resistance to natural substances,excellent adaptability to different harmful substances,and good removal of antibiotics in natural fresh water samples.The mechanism of action of boron for Fe^(3+)reduction was determined using scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS),Fourier transform infrared(FT-IR)spectroscopy,density functional theory(DFT)calculations,and electrochemical tests.The dominant role of^(·)OH was confirmed using quenching experiments,electron spin resonance(EPR)spectroscopy,and quantitative tests.Organic radicals(R-O^(·))and Fe(IV)also significantly contribute to the removal of SMT.DFT calculations on the reaction between Fe^(2+)and the PAA were conducted to further determine the contribution from ^(·)OH,R-O^(·),and Fe(IV)from the perspective of thermodynamics and the reaction pathways.Different boron dosages,Fe^(3+)dosages,and initial pH values were also investigated in the B/Fe^(3+)/PAA system to study their effect of SMT removal and the production of the reactive species.Fe(IV)production determined the k_(R-O·+Fe(IV))value suggesting that Fe(IV)may play a more important role than R-O^(·).A comparison of the results with other processes has also proved that the procedure described in this study(B/Fe^(3+)/PAA)is an effective method for the degradation of antibiotics.展开更多
The S-scheme heterojunction has garnered increasing attention due to its remarkable oxidation capacity and efficient separation of photogenerated carriers.In this study,a one-pot glycerol-assisted hydrothermal process...The S-scheme heterojunction has garnered increasing attention due to its remarkable oxidation capacity and efficient separation of photogenerated carriers.In this study,a one-pot glycerol-assisted hydrothermal process was utilized to successfully synthesize S-scheme heterojunction photocatalysts comprising basic bismuth nitrate(BBN)and bismuth tungstate(BWO).Interestingly,the BBN/BWO heterogeneous photo-catalysts exhibited the highest photocatalytic properties.The optimized product achieved the degradation of sulfamethazine(SMZ)within 1 h,with a kinetic constant(k)value of 0.05818 min^(−1).The degradation process was influenced significantly by·O^(2)−and h^(+)species.To determine the degradation pathway of SMZ in the presence of BBN/BWO-0.6,liquid chromatography-mass spectrometry(LC-MS)analysis was performed,which revealed a decrease in the toxicity of intermediates and products.The enhanced pho-tocatalytic activity can be attributed to the internal electric field(IEF)of the S-scheme heterojunction between BBN and BWO,effectively promoting the separation of photogenerated carriers.This research presents a viable approach for developing S-scheme heterojunctions in SMZ photodegradation and other environmental applications.展开更多
As a new type of environmental pollutant,antibiotic resistance genes(ARGs)pose a huge challenge to global health.Horizontal gene transfer(HGT)represents an important route for the spread of ARGs.The widespread use of ...As a new type of environmental pollutant,antibiotic resistance genes(ARGs)pose a huge challenge to global health.Horizontal gene transfer(HGT)represents an important route for the spread of ARGs.The widespread use of sulfamethazine(SM2)as a broad-spectrum bacteriostatic agent leads to high residual levels in the environment,thereby increasing the spread of ARGs.Therefore,we chose to study the effect of SM2 on the HGT of ARGs mediated by plasmid RP4 from Escherichia coli(E.coli)HB101 to E.coli NK5449 as well as its mechanism of action.The results showed that compared with the control group,SM2 at concentrations of 10 mg/L and 200 mg/L promoted the HGT of ARGs,but transfer frequency decreased at concentrations of 100 mg/L and 500 mg/L.The transfer frequency at 200 mg/L was 3.04×10^(−5),which was 1.34-fold of the control group.The mechanism of SM2 improving conjugation transfer is via enhancement of the mRNA expression of conjugation genes(trbBP,trfAP)and oxidative stress genes,inhibition of the mRNA expression of vertical transfer genes,up regulation of the outer membrane protein genes(ompC,ompA),promotion of the formation of cell pores,and improvement of the permeability of cell membrane to promote the conjugation transfer of plasmid RP4.The results of this study provide theoretical support for studying the spread of ARGs in the environment.展开更多
Removal characteristics of sulfamethazine （SMZ） by sludge and a bacterial strain using an aerobic sequence batch reactor （ASBR） were studied. Operating conditions were optimized by varying the reaction time and sl...Removal characteristics of sulfamethazine （SMZ） by sludge and a bacterial strain using an aerobic sequence batch reactor （ASBR） were studied. Operating conditions were optimized by varying the reaction time and sludge retention time （SRT）. AnAchromobacter sp. （S-3） with the ability to remove SMZ was isolated from the ASBR. The effects of different operating parameters （pH and temperature） on the biodegradation of SMZ by S-3 were determined. The results indicate that, between 0.5 and 4 hr, reaction time of the ASBR had a significant effect on the SMZ removal efficiency in the system. The SMZ removal efficiency also increased from 45% to 80% when SRT was prolonged from 5 to 25 days, although longer SRT had no impact on SMZ removal. The SMZ adsorption rate decreased with increasing temperature, which fitted Freundiich isotherm well. The removal of SMZ in the ASBR was due to the combined effects of adsorption and degradation, and degradation played a leading role.展开更多
Various disinfection byproducts(DBPs) form during the process of chlorination disinfection,posing potential threats to drinking water safety and human health. Sulfamethazine(SMT),the most commonly used and frequently ...Various disinfection byproducts(DBPs) form during the process of chlorination disinfection,posing potential threats to drinking water safety and human health. Sulfamethazine(SMT),the most commonly used and frequently detected veterinary antibiotic, was investigated in detail with regard to its transformation and kinetics in reactions with free available chlorine(FAC). Using liquid chromatography coupled to quadrupole time-of-flight tandem mass spectrometry, several DBPs were identified based on different confidence levels, and a variety of reaction types, including desulfonation, S–N cleavage, hydroxylation, and chlorine substitution, were proposed. The kinetic experiments indicated that the reaction rate was FAC-and pH-dependent, and SMT exhibits low reactivity toward FAC in alkaline conditions. The DBPs exhibited a much higher acute toxicity than SMT, as estimated by quantitative structure activity relationship models. More importantly, we observed that the FAC-treated SMT reaction solution might increase the genotoxic potential due to the generation of DBPs. This investigation provides substantial new details related to the transformation of SMT in the chlorination disinfection process.展开更多
Photocatalytic technology can solve various environmental pollution problems,especially antibiotic pollution.A novel La-doped MIL-53(Al)/ZnO composite material was successfully synthesized by a combination of hydrothe...Photocatalytic technology can solve various environmental pollution problems,especially antibiotic pollution.A novel La-doped MIL-53(Al)/ZnO composite material was successfully synthesized by a combination of hydrothermal method and calcination,showing high photocatalytic degradation percent of sulfamethazine(SMT).The 2 mol%La MIL-53(Al)/ZnO photocatalyst shows the highest degradation efficiency toward SMT(92%)within 120 min,which is 4.1 times higher than pure ZnO(increased from 18%to 92%).In addition,the degradation analysis of SMT by high performance liquid chromatography proves that the products are CO_(2) and H_(2)O.The improved photocatalytic activity is mostly caused by the following factors.(1)Doping La ions can decrease the band gap of ZnO,enhance light response,and effectively enhance the separation rate of photo-generated holes and electrons.(2)MIL-53(Al)can adsorb SMT and promote the separation of electron.This work shows that the synthesized La-doped MIL-53(Al)/ZnO photocatalyst is expected to be used as a green and effective method for treatment of environment water pollution.展开更多
The biofiltering capacity, distribution patterns and degradation of the antimicrobial sulfamethazine(SMT) by halophyte Chenopodium quinoa under hydroponic conditions and its further biodegradation through anaerobic di...The biofiltering capacity, distribution patterns and degradation of the antimicrobial sulfamethazine(SMT) by halophyte Chenopodium quinoa under hydroponic conditions and its further biodegradation through anaerobic digestion were evaluated. C. quinoa was cultivated for a complete life cycle under different concentrations of SMT(0, 2 and 5 mg/L) and sodium chloride(0 and 15 g/L). C. quinoa is able to uptake and partially degrade SMT. The higher the SMT concentration in the culture medium, the higher the SMT content in the plant tissue. SMT has different distribution patterns within the plant organs, and no SMT is found in the seeds.Dry crop residues containing SMT have a great potential to produce methane through anaerobic digestion and, in addition, SMT is further biodegraded. The highest specific methane yields are obtained using crop residues of the plants cultivated in the presence of salt and SMT with concentrations between 0 and 2 mg/L.展开更多
Sulfamethazine(SMZ) is an important sulfonamide antibiotic.Although the concentration in the environment is small,it is harmful.The drug residues can be transferred,transformed or accumulated,affecting the growth of a...Sulfamethazine(SMZ) is an important sulfonamide antibiotic.Although the concentration in the environment is small,it is harmful.The drug residues can be transferred,transformed or accumulated,affecting the growth of animals and plants.In this study,the integrated fixed-film activated sludge membrane bioreactor(IFAS-MB R) were constructed to investigate the performance and degradation mechanism of SMZ.The addition of SMZ had a significant impact on the removal of the chemical oxygen demand(COD) and ammonia nitrogen(NH_4^+-N).The optimal operating conditions were hydraulic retention time(HRT) at 10 h and solid retention time(SRT) at 80 d,respectively.On this basis,the effects of different SMZ concentrations on nutrient removal,degradation,and sludge characteristics were compared.The removal efficiency of SMZ increased with the increase of SMZ concentration.The maximum removal rate was as high as 87%.The SMZ dosage also had an obvious effect on sludge characteristics.As the SMZ concentration increased,the extracellular polymer substances(EPS) concentration and the membrane resistance both decreased,which were beneficial for the reduction of membrane fouling.Finally,seven kinds of SMZ biodegradation intermediates were identified,and the possible degradation pathways were speculated.The microbial community results showed that the microbial diversity and richness in the reactor decreased after adding SMZ to the influent.The relative abundance of Bacteroidetes,Actinobacteria,Saccharibacteria and Nitro spirae increased at the phylum level.Sphingobacteria and Betaproteobacteria became dominant species at the class level.The relative abundance of norankp-Saccharibacteria and Nitrospirae increased significantly,and norank-p-Saccharibacteria may be the dominant bacteria for SMZ degradation.展开更多
Sulfonamides are used in human therapy, animal husbandry and agriculture but are not easily biodegradable, and are often detected in surface water. Sulfamethazine （SMZ） and sulfadiazine （SDZ） are two widely used s...Sulfonamides are used in human therapy, animal husbandry and agriculture but are not easily biodegradable, and are often detected in surface water. Sulfamethazine （SMZ） and sulfadiazine （SDZ） are two widely used sulfonamide antibiotics that are used heavily in agriculture. In this study, they were degraded in an aqueous system by chlorination after pre-oxidation with ferrate（VI） （FeVIO2-, Fe（VI））, an environmentally friendly oxidation technique that has been shown to be effective in degrading various organics. The kinetics of the degradation were determined as a function of Fe（VI） （0-1.5 mg/L）, free chlorine （0-1.8 mg/L） and temperature （15- 35℃）. According to the experimental results, SMZ chlorination followed second-order kinetics with increasing Fe（VI） dosage, and the effect of the initial free chlorine concentration on the reaction kinetics with pre-oxidation by Fe（VI） fitted a pseudo-first order model. The rate constants of SDZ and SMZ chlorination at different temperatures were related to the Arrhenius equation. Fe（VI） could reduce the levels of THMs formed and the toxicity of the sulfonamide degradation systems with Fe（VI） doses of 0.5-1.5 mg/L, which provides a reference for ensuring water quality in drinking water systems.展开更多
基金funded by the Ministry of Agriculture of China (2013-Z10)Chinese Academy of Agricultural Sciences (2012ZL071)Institute of Animal Science, Chinese Academy of Agricultural Sciences (2013ywf-yb-4)
文摘This study surveyed 180 samples of ultra high temperature （UHT） milk of four top Chinese dairy brands collected in the 25 cities in China in June 2011, and assessed their contamination with antibiotics, using the ELISA method. The percentages of tetracyclines, sulfonamides, sulfamethazine, and quinolones detected in the samples were 0, 16.7, 40.6, and 100%, respectively. The maximum concentrations of the tetracyclines, sulfonamides, sulfamethazine and quinolones in UHT milk samples were 〈1.5, 26.2, 22.6, and 58.8 μg kg-1, respectively. None of the samples exceeded the maximum residue levels （MRLs） for these four veterinary drugs, according to the regulations set by China, the European Union （EU） and the Codex Alimentarius Commission （CAC）.
基金supported by the earmarked fund for the Modern Agro-Industry Technology Research System (CARS-47)the Program of Shandong Leading Talent (No.LJNY2015002)the AoShan Scientific and Technological Innovation Project which was financially backed by Qingdao National Laboratory for Marine Science and Technology (No.2015ASKJ02)
文摘Intensive use of sulfamethazine(SM_2) in aquaculture has resulted in some detrimental effects to non-targeted organisms. In order to assess its potential ecological risk, it is crucial to have a good understanding on the bioaccumulation and biodegradation of SM_2 in Chlorella pyrenoidosa. The microalgae were treated with 2, 4, and 8 mg L^(-1) of sulfamethazine for 13 days, respectively, showing that the inhibition effects of sulfamethazine on the growth of Chlorella pyrenoidosa increased progressively as the concentrations of sulfamethazine increasing from 2 to 8 mg L^(-1). The peak concentrations of sulfamethazine accumulated in C. pyrenoidosa were 0.225, 0.325, and 0.596 ng per mg FW on day 13 for three treatment groups, respectively, showing a great ability to deplete sulfamethazine from the culture media. On day 13, the percentages of biotic degradation were 48.45%, 60.21% and 69.93%, respectively. The EC_(50) of 10.05 mg L^(-1) was derived which showed no significant risk for C. pyrenoidosa with a calculated risk quotient < 1. The activities of superoxide dismutase and catalase increased progressively in response to sulfamethazine and showed a positive correlation to the treatment concentrations. The highest superoxide dismutase activity was achieved at the concentration of 8 mg L^(-1) after 2 d of exposure, which was 1.89 folds higher than that of the control. The activity of catalase has a similar pattern to that of superoxide dismutase with the maximum activity achieved at day 2, which was 3.11 folds higher compared to that of the control. In contrast to superoxide dismutase and catalase, the maximum glutathione S-transferase activity was observed at day 6, showing 2.2 folds higher than that of the control.
基金supported by the National Natural Science Foundation of China(51778505)the grants from Hubei Province of China(Special Grant for Technological Innovation(2016ACA162)the Natural Science Foundation,2015CFA017)~~
文摘In the present study,zinc molybdate(β‐ZnMoO4)and graphitic carbon nitride(g‐C3N4)‐modifiedβ‐ZnMoO4(β‐ZnMoO4/g‐C3N4)were prepared to decontaminate aqueous solutions from the antibiotic sulfamethazine(SMZ).Our results revealed that the hydrothermal synthesis method greatly influenced the photocatalytic activity of the resultant catalysts.The pristineβ‐ZnMoO4samples obtained under more intensive synthesis conditions(24h at280°C)showed higher photocatalytic activity than that prepared for12h at180°C(denotedβ‐ZnMoO4‐180).In the case of in situ hydrothermal synthesis ofβ‐ZnMoO4/g‐C3N4,a surface‐modified sample was only obtained under the reaction conditions of180°C for12h.Compared with the sheet‐likeβ‐ZnMoO4‐180sample,theβ‐ZnMoO4‐180/g‐C3N4composite showed enhanced photocatalytic activity for the degradation of SMZ.By contrast,the hydrothermal reaction at280°C caused the gradual decomposition of g‐C3N4.It is believed that the structural incorporation of g‐C3N4intoβ‐ZnMoO4at280°C might disrupt the crystal growth,thereby deteriorating the performance of the composite catalysts formed at this temperature.For the composite catalysts prepared by the ultrasonic method,a remarkable increase in the degradation rate of SMZ was only observed at a high g‐C3N4content of8mol%.The photocatalytic degradation of SMZ byβ‐ZnMoO4‐180/g‐C3N4composite catalysts followed pseudo‐first‐order kinetics.Further study of the photocatalytic mechanism revealed that holes and superoxide radicals were the dominant oxidative species in the photodegradation process.The enhanced photocatalytic performance of the composites was attributed to the higher separation efficiency of the photogenerated electron‐hole pairs at heterogeneous junctions.The degradation intermediates of SMZ were detected by liquid chromatography‐mass spectrometry,from which plausible reaction pathways for the photodegradation of SMZ were proposed.Our results indicated that the synthesis method for g‐C3N4composites should be carefully selected to achieve superior photocatalytic performance.
文摘Two artificial antigens were synthesized successfully by diazotizing method, sulfamethazine（SM2）-human serum albumin （HSA） was used for the immunogen, and SM2-ovalbumin（OVA） was used for the coating antigen. The coupled reaction was successful by confirmation of the ultraviolet scanning spectrometer, and the conjugation ratio of SM2 with HSA and OVA was 9：1 and 15：1, respectively. Using cell-fusion and limiting dilution method to reclone 5 times to get 3 hybridoma strains, which could stably secret monoclonal antibody （Mab）, named CBT, BC4 and BB12. The subtype of BC4 Mab was IgG1 and chain, the molecular weight was 162 ku, the numbers of chromosomal were about 90, the affinity constant was 6.1 × 10^12 M^-1. No cross reactivity was seen between the Mab and the other 4 sulfonamides, as well as the 2 carries proteins. The Mab antibody had excellent stability.
基金Funds for the Central Universities of China(No.201964004)the National Natural Science Foundation of China(No.41977315).
文摘Sorption mechanisms of sulfamethazine(SMT)in different pH solutions are complicated.It has not been sufficiently investigated to enhance removal of SMT from alkalescent aqueous solution.In this study,sorption isotherms and kinetics of SMT by corn biochars pyrolyzed at 300℃ and 600℃(300C,600C)under diverse pH conditions were compared.In order to improve the sorption efficiency of SMT from alkalescent aqueous solution,the biochar 300C was modified by acid or base.Different mathematic models were used to describe sorption driving force and sorption process.Results showed that the biochar 300C possessed more amorphous organic carbon and polar functional groups,which led to a higher sorption capacity than biochar 600C.The sorption rate of biochar 300C was greater than 600C under diverse pH as the physisorption of 300C outweighed 600C.The SMT presented stronger hydrophobicity at pH 5 and higher electrostatic repulsion at pH 1 or 8,which resulted in a higher combining capacity of SMT with both biochars at pH 5 than other pH values.In addition,the acid modified biochar had better removal effect on SMT than alkali at pH solution around 8.The research provides a theoretical basis for the removal of SMT from alkalescent aqueous solution.
基金The authors greatly acknowledge the financial support from the National Natural Science Foundation of China(No.60027001 and 60302003)the National High Technology Research and Development program of China(No.20060100Z3044).
文摘A homemade array surface plasmon resonance （SPR）-based imaging biosensor was used to develop sensitive and fast immunoassays to determine sulfamethoxazole （SMOZ） and sulfamethazine （SMT） in buffer. Two conjugations of sulfonamide-bovine serum albumin （BSA） were separately immobilized on two different rows of the array chip with one row as reference. The immobilization was carried out in the instrument to monitor the quantity of the conjugations immobilized. The antibody mixed with the sulfonamide in the buffer was injected over the surface of the chip to get a relative response which was inversely proportional to the concentration of the sulfonamide in the PBS buffer. Two calibration curves were constructed and the limit of detection for sufamethoxazole in buffer was 3.5 ng/mL and for sulfamethazine 0.6 ng/mL. The stability and specificity of the antibody were also studied. The monoclonal antibody did not bind with BSA.
基金Supported by Key Items of National Technology Research Project(2002BA518A06)Heilongjiang Provincial Science and Technology Tackle Key Problem Project(10541021)Harbin Technical Fund(2003AA6CN179)
文摘In this study, various factors of ELISA for detection of sulfamethazine residues were explored, the coating antigen was diluted to 1：400, the best coating condition was at 4℃ overnight, the working concentration of HRP-IgG enzyme conjugate was 1 ： 7 000. The pre-incubation time and incubation time was 30 min and 120 min, respectively, the substrate solution working time was 20 min. Two moL · L^-1 H2SO4 was used to stop the reaction and checked. A standard curve of direct competitive ELISA had been established to detect the sulfamethazine residues in milk. The detection limit of this method was 1.97 ng · mL^-1. The mean concentration of sulfamethazine required to inhibit 30% antibody was 7.1 ng · mL^-1. The linear range of the detection was 5-200 ng · mL^-1. The recovery ratio was between 73.20% and 91.16%. The CV% of within array and between arrays was less than 10%.
基金supported by the Natural Science Foundation of Jiangsu Province in China (No.BK20210952)the Jiangsu Provincial Key Laboratory of Environmental Engineering (No.ZX2022002)+2 种基金the National Natural Science Foundation of China (Nos.52200095,22176102,and 21806081)the China Postdoctoral Science Foundation Project (No.2020M681552)the Natural Science Foundation of Tianjin (No.19JCQNJC07900)。
文摘In this work,boron(B)was used to promote Fe^(3+)/peracetic acid(Fe^(3+)/PAA)for the degradation of sulfamethazine(SMT).An SMT degradation efficiency of 9.1%was observed in the Fe^(3+)/PAA system over 60 min,which was significantly increased to 99.3%in the B/Fe^(3+)/PAA system over 10 min.The B/Fe^(3+)/PAA process also exhibited superior resistance to natural substances,excellent adaptability to different harmful substances,and good removal of antibiotics in natural fresh water samples.The mechanism of action of boron for Fe^(3+)reduction was determined using scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS),Fourier transform infrared(FT-IR)spectroscopy,density functional theory(DFT)calculations,and electrochemical tests.The dominant role of^(·)OH was confirmed using quenching experiments,electron spin resonance(EPR)spectroscopy,and quantitative tests.Organic radicals(R-O^(·))and Fe(IV)also significantly contribute to the removal of SMT.DFT calculations on the reaction between Fe^(2+)and the PAA were conducted to further determine the contribution from ^(·)OH,R-O^(·),and Fe(IV)from the perspective of thermodynamics and the reaction pathways.Different boron dosages,Fe^(3+)dosages,and initial pH values were also investigated in the B/Fe^(3+)/PAA system to study their effect of SMT removal and the production of the reactive species.Fe(IV)production determined the k_(R-O·+Fe(IV))value suggesting that Fe(IV)may play a more important role than R-O^(·).A comparison of the results with other processes has also proved that the procedure described in this study(B/Fe^(3+)/PAA)is an effective method for the degradation of antibiotics.
基金supported by the National Natural Science Foundation of China(No.22278245)the Young Taishan Scholars Program of Shandong Province(No.tsqn.201909026)+1 种基金the Youth Interdisciplinary Science and Innovative Research Groups of Shandong University supported by the Fundamental Research Funds for the Central Universities(No.2020QNQT014)the Shandong University Future Youth Grant Program(No.61440089964189).
文摘The S-scheme heterojunction has garnered increasing attention due to its remarkable oxidation capacity and efficient separation of photogenerated carriers.In this study,a one-pot glycerol-assisted hydrothermal process was utilized to successfully synthesize S-scheme heterojunction photocatalysts comprising basic bismuth nitrate(BBN)and bismuth tungstate(BWO).Interestingly,the BBN/BWO heterogeneous photo-catalysts exhibited the highest photocatalytic properties.The optimized product achieved the degradation of sulfamethazine(SMZ)within 1 h,with a kinetic constant(k)value of 0.05818 min^(−1).The degradation process was influenced significantly by·O^(2)−and h^(+)species.To determine the degradation pathway of SMZ in the presence of BBN/BWO-0.6,liquid chromatography-mass spectrometry(LC-MS)analysis was performed,which revealed a decrease in the toxicity of intermediates and products.The enhanced pho-tocatalytic activity can be attributed to the internal electric field(IEF)of the S-scheme heterojunction between BBN and BWO,effectively promoting the separation of photogenerated carriers.This research presents a viable approach for developing S-scheme heterojunctions in SMZ photodegradation and other environmental applications.
基金supported by the National Natural Science Foundation of China(No.41671320)the Natural Science Foundation of Shandong Province,China(No.ZR2016JL029)and the Special Funds of Taishan Scholar of Shandong Province,China.
文摘As a new type of environmental pollutant,antibiotic resistance genes(ARGs)pose a huge challenge to global health.Horizontal gene transfer(HGT)represents an important route for the spread of ARGs.The widespread use of sulfamethazine(SM2)as a broad-spectrum bacteriostatic agent leads to high residual levels in the environment,thereby increasing the spread of ARGs.Therefore,we chose to study the effect of SM2 on the HGT of ARGs mediated by plasmid RP4 from Escherichia coli(E.coli)HB101 to E.coli NK5449 as well as its mechanism of action.The results showed that compared with the control group,SM2 at concentrations of 10 mg/L and 200 mg/L promoted the HGT of ARGs,but transfer frequency decreased at concentrations of 100 mg/L and 500 mg/L.The transfer frequency at 200 mg/L was 3.04×10^(−5),which was 1.34-fold of the control group.The mechanism of SM2 improving conjugation transfer is via enhancement of the mRNA expression of conjugation genes(trbBP,trfAP)and oxidative stress genes,inhibition of the mRNA expression of vertical transfer genes,up regulation of the outer membrane protein genes(ompC,ompA),promotion of the formation of cell pores,and improvement of the permeability of cell membrane to promote the conjugation transfer of plasmid RP4.The results of this study provide theoretical support for studying the spread of ARGs in the environment.
基金supported by the National Natural Science Foundation of China(No.21007010)the Research Fund for the Doctoral Program of Higher Education of China(No.20090075120007)+4 种基金the Shanghai Committee of Science and Technology(No.09230500200)the Fundamental Research Funds for the Central Universities(No. 2011D11309)the Joint Funds of Chinese Transportation Ministry and Hunan Province for Science and Technology Development(No.2010-353-343-290)the Knowledge Innovation Program of the Chinese Academy of Sciences (No.KZCX2-YW-Q02-02,KZCX2-YW-BR-19)the Project of Transportation Department of Hunan Province (No.200908)
文摘Removal characteristics of sulfamethazine （SMZ） by sludge and a bacterial strain using an aerobic sequence batch reactor （ASBR） were studied. Operating conditions were optimized by varying the reaction time and sludge retention time （SRT）. AnAchromobacter sp. （S-3） with the ability to remove SMZ was isolated from the ASBR. The effects of different operating parameters （pH and temperature） on the biodegradation of SMZ by S-3 were determined. The results indicate that, between 0.5 and 4 hr, reaction time of the ASBR had a significant effect on the SMZ removal efficiency in the system. The SMZ removal efficiency also increased from 45% to 80% when SRT was prolonged from 5 to 25 days, although longer SRT had no impact on SMZ removal. The SMZ adsorption rate decreased with increasing temperature, which fitted Freundiich isotherm well. The removal of SMZ in the ASBR was due to the combined effects of adsorption and degradation, and degradation played a leading role.
基金supported by the Capital Health Research and Development of Special (No.2014-1-3011)
文摘Various disinfection byproducts(DBPs) form during the process of chlorination disinfection,posing potential threats to drinking water safety and human health. Sulfamethazine(SMT),the most commonly used and frequently detected veterinary antibiotic, was investigated in detail with regard to its transformation and kinetics in reactions with free available chlorine(FAC). Using liquid chromatography coupled to quadrupole time-of-flight tandem mass spectrometry, several DBPs were identified based on different confidence levels, and a variety of reaction types, including desulfonation, S–N cleavage, hydroxylation, and chlorine substitution, were proposed. The kinetic experiments indicated that the reaction rate was FAC-and pH-dependent, and SMT exhibits low reactivity toward FAC in alkaline conditions. The DBPs exhibited a much higher acute toxicity than SMT, as estimated by quantitative structure activity relationship models. More importantly, we observed that the FAC-treated SMT reaction solution might increase the genotoxic potential due to the generation of DBPs. This investigation provides substantial new details related to the transformation of SMT in the chlorination disinfection process.
基金Project supported by the National Natural Science Foundation of China (11674106)。
文摘Photocatalytic technology can solve various environmental pollution problems,especially antibiotic pollution.A novel La-doped MIL-53(Al)/ZnO composite material was successfully synthesized by a combination of hydrothermal method and calcination,showing high photocatalytic degradation percent of sulfamethazine(SMT).The 2 mol%La MIL-53(Al)/ZnO photocatalyst shows the highest degradation efficiency toward SMT(92%)within 120 min,which is 4.1 times higher than pure ZnO(increased from 18%to 92%).In addition,the degradation analysis of SMT by high performance liquid chromatography proves that the products are CO_(2) and H_(2)O.The improved photocatalytic activity is mostly caused by the following factors.(1)Doping La ions can decrease the band gap of ZnO,enhance light response,and effectively enhance the separation rate of photo-generated holes and electrons.(2)MIL-53(Al)can adsorb SMT and promote the separation of electron.This work shows that the synthesized La-doped MIL-53(Al)/ZnO photocatalyst is expected to be used as a green and effective method for treatment of environment water pollution.
文摘The biofiltering capacity, distribution patterns and degradation of the antimicrobial sulfamethazine(SMT) by halophyte Chenopodium quinoa under hydroponic conditions and its further biodegradation through anaerobic digestion were evaluated. C. quinoa was cultivated for a complete life cycle under different concentrations of SMT(0, 2 and 5 mg/L) and sodium chloride(0 and 15 g/L). C. quinoa is able to uptake and partially degrade SMT. The higher the SMT concentration in the culture medium, the higher the SMT content in the plant tissue. SMT has different distribution patterns within the plant organs, and no SMT is found in the seeds.Dry crop residues containing SMT have a great potential to produce methane through anaerobic digestion and, in addition, SMT is further biodegraded. The highest specific methane yields are obtained using crop residues of the plants cultivated in the presence of salt and SMT with concentrations between 0 and 2 mg/L.
基金financially supported by the Major Science and Technology Program for Water Pollution Control and Treatment(No.2018ZX07601-003)the Fundamental Research Funds for Central Public Research Institutes of China(No.2019-YSKY-009)。
文摘Sulfamethazine(SMZ) is an important sulfonamide antibiotic.Although the concentration in the environment is small,it is harmful.The drug residues can be transferred,transformed or accumulated,affecting the growth of animals and plants.In this study,the integrated fixed-film activated sludge membrane bioreactor(IFAS-MB R) were constructed to investigate the performance and degradation mechanism of SMZ.The addition of SMZ had a significant impact on the removal of the chemical oxygen demand(COD) and ammonia nitrogen(NH_4^+-N).The optimal operating conditions were hydraulic retention time(HRT) at 10 h and solid retention time(SRT) at 80 d,respectively.On this basis,the effects of different SMZ concentrations on nutrient removal,degradation,and sludge characteristics were compared.The removal efficiency of SMZ increased with the increase of SMZ concentration.The maximum removal rate was as high as 87%.The SMZ dosage also had an obvious effect on sludge characteristics.As the SMZ concentration increased,the extracellular polymer substances(EPS) concentration and the membrane resistance both decreased,which were beneficial for the reduction of membrane fouling.Finally,seven kinds of SMZ biodegradation intermediates were identified,and the possible degradation pathways were speculated.The microbial community results showed that the microbial diversity and richness in the reactor decreased after adding SMZ to the influent.The relative abundance of Bacteroidetes,Actinobacteria,Saccharibacteria and Nitro spirae increased at the phylum level.Sphingobacteria and Betaproteobacteria became dominant species at the class level.The relative abundance of norankp-Saccharibacteria and Nitrospirae increased significantly,and norank-p-Saccharibacteria may be the dominant bacteria for SMZ degradation.
基金supported by the National Natural Science Foundation of China(Nos.51778565,51578487)the Zhejiang Provincial Natural Science Foundation of China(No.LY15E080005)
文摘Sulfonamides are used in human therapy, animal husbandry and agriculture but are not easily biodegradable, and are often detected in surface water. Sulfamethazine （SMZ） and sulfadiazine （SDZ） are two widely used sulfonamide antibiotics that are used heavily in agriculture. In this study, they were degraded in an aqueous system by chlorination after pre-oxidation with ferrate（VI） （FeVIO2-, Fe（VI））, an environmentally friendly oxidation technique that has been shown to be effective in degrading various organics. The kinetics of the degradation were determined as a function of Fe（VI） （0-1.5 mg/L）, free chlorine （0-1.8 mg/L） and temperature （15- 35℃）. According to the experimental results, SMZ chlorination followed second-order kinetics with increasing Fe（VI） dosage, and the effect of the initial free chlorine concentration on the reaction kinetics with pre-oxidation by Fe（VI） fitted a pseudo-first order model. The rate constants of SDZ and SMZ chlorination at different temperatures were related to the Arrhenius equation. Fe（VI） could reduce the levels of THMs formed and the toxicity of the sulfonamide degradation systems with Fe（VI） doses of 0.5-1.5 mg/L, which provides a reference for ensuring water quality in drinking water systems.
