Objective:PCDD/Fs level in 22 fish samples was investigated in Pearl river Delta area in order thatthe PCDD/Fs pollution level in common fish can be evaluated.Methods:Dibenzo-p-Dioxins andDibenzo-Furans was extracted ...Objective:PCDD/Fs level in 22 fish samples was investigated in Pearl river Delta area in order thatthe PCDD/Fs pollution level in common fish can be evaluated.Methods:Dibenzo-p-Dioxins andDibenzo-Furans was extracted from the sample by Soxhlet extraction,concentrated then purified by columnchromatography,carbon column enrichment,.Confirmation and quantitative analysis at ppt(pg/g) level ofPCDD/Fs was performed by HRGC/HRMS using multiple ion detection mode(MID).Certified referencematerial using Proficiency test sample——fish muscle test material 0613 that was obtained from CentralScience Laboratory(CSL) in Britain.Results:The average of concentration in wet weight is 1.261 ng/kg,,theaverage total WHO-TEQ for 22 samples is 0.246ng/kg wet weight.Generally,OCDD,2,3,7,8-TCDF,1,2,3,4,6,7,8-HpCDD was the main contributors to the total 17 PCDD/Fs detected,average account for21%,16%,14%,respectively.While 1,2,3,7,8-PeCDD,2,3,4,7,8-PeCDF,2,3,7,8-TCDD were main contributorsto the total WHO-TEQ,account for 40%,27%,13% respectively.The total TEQ for 22 fishes ranged from 0.03ng/kg wet weight to 0.878 ng/kg wet weight.Conclusions:PCDD/Fs level was largely different from sample tosample depending on the sample kinds.The level in the Pearl river Delta area fish samples is not distinctcomparing with other countries,but some kind fish level should be paid more attention on it since its higherlevel.The relationship between source of PCDD/Fs and PCDD/Fs level in fish will be studied deeply in thefuture.展开更多
Bismuth oxide/titania, one interfacial composite semiconductor with high photocatalytic activity under solar light, was prepared at low temperature. The structure was characterized by X-ray diffractometry （XRD）, sca...Bismuth oxide/titania, one interfacial composite semiconductor with high photocatalytic activity under solar light, was prepared at low temperature. The structure was characterized by X-ray diffractometry （XRD）, scanning electron microscopy （SEM）, brunauer-emmett-teller （BET）, X-ray photoelectron spectroscopy （XPS） and diffuse reflection spectra （DRS）. The results indicate that deposited titania nanoparticles on bismuth oxide surface have micro-nano structure, and this composite material exhibits porosity and increased surface hydroxyl groups. Furthermore, the as-prepared photocatalyst shows higher photocatalytic activity to the degradation of 4-chlorophenol than pure titania or P25 under sunlight.展开更多
As a good antimicrobial active ingredient, 2,4,4′ trichloro 2′ hydroxydiphenyl ether has been already commercially available since 1970s. For this paper halogenated hydroxydiphenyl ethers were prepared and purifi...As a good antimicrobial active ingredient, 2,4,4′ trichloro 2′ hydroxydiphenyl ether has been already commercially available since 1970s. For this paper halogenated hydroxydiphenyl ethers were prepared and purified, and their analytical conditions by HPLC were studied. Further purification of 2,4,4′ trichloro 2′ hydroxydiphenyl ether was also studied. The adsorption ability of different decolourants, e.g. alumina and bentonite, for each component in crude product of 2,4,4′ trichloro 2′ hydroxydiphenyl ether was varied. 2,4,4′ trichloro 2′ hydroxydiphenyl ether might be adsorbed by active carbon. The colored impurities might be adsorbed by alumina. The colorless impurities might be adsorbed by bentonite.展开更多
Synthesis of p toluidine o sulfonic acid from p toluidine by sulfonation in solvent was studied,and effects of various reaction conditions or factors on the reaction were discussed in detail.As a result,the follow...Synthesis of p toluidine o sulfonic acid from p toluidine by sulfonation in solvent was studied,and effects of various reaction conditions or factors on the reaction were discussed in detail.As a result,the following optimum process conditions are presented:50 mL dichlorobenzene,2%～5% oleum,molar ratio of sulfonating agent to p toluidine is 1.10～1.12,oleum is dropped in the reaction system in 10 min or so,sulfate formation time is 2 h,distillation lasts 8 h.Under the above conditions,the purity and the yield of p toluidine o sulfonic acid are better than that of the same product made in Japan.展开更多
Exfoliation of bulk graphitic carbon nitride(g‐C3N4)into two‐dimensional(2D)nanosheets is one of the effective strategies to improve its photocatalytic properties so that the 2D g‐C3N4 nanosheets(CN)have larger spe...Exfoliation of bulk graphitic carbon nitride(g‐C3N4)into two‐dimensional(2D)nanosheets is one of the effective strategies to improve its photocatalytic properties so that the 2D g‐C3N4 nanosheets(CN)have larger specific surface areas and more reaction sites.In addition,poly‐o‐phenylenediamine(PoPD)can improve the electrical conductivity and photocatalytic activity of semiconductor materials.Here,the novel efficient composite PoPD/AgCl/g‐C3N4 nanosheets was first synthesized by a precipitation reaction and the photoinitiated polymerization approach.The obtained photocatalysts have larger specific surface areas and could achieve better visible‐light response.However,silver chloride(AgCl)is susceptible to agglomeration and photocorrosion.The PoPD/AgCl/CN composite exhibits an extremely high photocurrent density,which is three times that of CN.Obviously enhanced photocatalytic activities of PoPD/AgCl/g‐C3N4 are revealed through the photodegradation of tetracycline.The stability of PoPD/AgCl/CN is demonstrated based on four cycles of experiments that reveal that the degradation rate only decreases slightly.Furthermore,.O2^-and h+are the main active species,which are confirmed through a trapping experiment and ESR spin‐trap technique.Therefore,the prepared PoPD/AgCl/CN can be considered as a stable photocatalyst,in which PoPD is added as a charge carrier and acts a photosensitive protective layer on the surface of the AgCl particles.This provides a new technology for preparing highly stable composite photocatalysts that can effectively deal with environmental issues.展开更多
文摘Objective:PCDD/Fs level in 22 fish samples was investigated in Pearl river Delta area in order thatthe PCDD/Fs pollution level in common fish can be evaluated.Methods:Dibenzo-p-Dioxins andDibenzo-Furans was extracted from the sample by Soxhlet extraction,concentrated then purified by columnchromatography,carbon column enrichment,.Confirmation and quantitative analysis at ppt(pg/g) level ofPCDD/Fs was performed by HRGC/HRMS using multiple ion detection mode(MID).Certified referencematerial using Proficiency test sample——fish muscle test material 0613 that was obtained from CentralScience Laboratory(CSL) in Britain.Results:The average of concentration in wet weight is 1.261 ng/kg,,theaverage total WHO-TEQ for 22 samples is 0.246ng/kg wet weight.Generally,OCDD,2,3,7,8-TCDF,1,2,3,4,6,7,8-HpCDD was the main contributors to the total 17 PCDD/Fs detected,average account for21%,16%,14%,respectively.While 1,2,3,7,8-PeCDD,2,3,4,7,8-PeCDF,2,3,7,8-TCDD were main contributorsto the total WHO-TEQ,account for 40%,27%,13% respectively.The total TEQ for 22 fishes ranged from 0.03ng/kg wet weight to 0.878 ng/kg wet weight.Conclusions:PCDD/Fs level was largely different from sample tosample depending on the sample kinds.The level in the Pearl river Delta area fish samples is not distinctcomparing with other countries,but some kind fish level should be paid more attention on it since its higherlevel.The relationship between source of PCDD/Fs and PCDD/Fs level in fish will be studied deeply in thefuture.
基金Project supported by the Scientific Research Foundation of Nanjing University of Information Science and Technology, ChinaProject (2010490511) supported by the Open Foundation of State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, China
文摘Bismuth oxide/titania, one interfacial composite semiconductor with high photocatalytic activity under solar light, was prepared at low temperature. The structure was characterized by X-ray diffractometry （XRD）, scanning electron microscopy （SEM）, brunauer-emmett-teller （BET）, X-ray photoelectron spectroscopy （XPS） and diffuse reflection spectra （DRS）. The results indicate that deposited titania nanoparticles on bismuth oxide surface have micro-nano structure, and this composite material exhibits porosity and increased surface hydroxyl groups. Furthermore, the as-prepared photocatalyst shows higher photocatalytic activity to the degradation of 4-chlorophenol than pure titania or P25 under sunlight.
文摘As a good antimicrobial active ingredient, 2,4,4′ trichloro 2′ hydroxydiphenyl ether has been already commercially available since 1970s. For this paper halogenated hydroxydiphenyl ethers were prepared and purified, and their analytical conditions by HPLC were studied. Further purification of 2,4,4′ trichloro 2′ hydroxydiphenyl ether was also studied. The adsorption ability of different decolourants, e.g. alumina and bentonite, for each component in crude product of 2,4,4′ trichloro 2′ hydroxydiphenyl ether was varied. 2,4,4′ trichloro 2′ hydroxydiphenyl ether might be adsorbed by active carbon. The colored impurities might be adsorbed by alumina. The colorless impurities might be adsorbed by bentonite.
文摘Synthesis of p toluidine o sulfonic acid from p toluidine by sulfonation in solvent was studied,and effects of various reaction conditions or factors on the reaction were discussed in detail.As a result,the following optimum process conditions are presented:50 mL dichlorobenzene,2%～5% oleum,molar ratio of sulfonating agent to p toluidine is 1.10～1.12,oleum is dropped in the reaction system in 10 min or so,sulfate formation time is 2 h,distillation lasts 8 h.Under the above conditions,the purity and the yield of p toluidine o sulfonic acid are better than that of the same product made in Japan.
基金supported by the National Natural Science Foundation of China(21576125,21776117)the China Postdoctoral Science Foundation(2017M611716,2017M611734)+1 种基金the Six talent peaks project of Jiangsu Province(XCL-014)the Zhenjiang Science&Technology Program(SH2016012)~~
文摘Exfoliation of bulk graphitic carbon nitride(g‐C3N4)into two‐dimensional(2D)nanosheets is one of the effective strategies to improve its photocatalytic properties so that the 2D g‐C3N4 nanosheets(CN)have larger specific surface areas and more reaction sites.In addition,poly‐o‐phenylenediamine(PoPD)can improve the electrical conductivity and photocatalytic activity of semiconductor materials.Here,the novel efficient composite PoPD/AgCl/g‐C3N4 nanosheets was first synthesized by a precipitation reaction and the photoinitiated polymerization approach.The obtained photocatalysts have larger specific surface areas and could achieve better visible‐light response.However,silver chloride(AgCl)is susceptible to agglomeration and photocorrosion.The PoPD/AgCl/CN composite exhibits an extremely high photocurrent density,which is three times that of CN.Obviously enhanced photocatalytic activities of PoPD/AgCl/g‐C3N4 are revealed through the photodegradation of tetracycline.The stability of PoPD/AgCl/CN is demonstrated based on four cycles of experiments that reveal that the degradation rate only decreases slightly.Furthermore,.O2^-and h+are the main active species,which are confirmed through a trapping experiment and ESR spin‐trap technique.Therefore,the prepared PoPD/AgCl/CN can be considered as a stable photocatalyst,in which PoPD is added as a charge carrier and acts a photosensitive protective layer on the surface of the AgCl particles.This provides a new technology for preparing highly stable composite photocatalysts that can effectively deal with environmental issues.
