Highly dispersed negative carboxyl groups can be formed on carbon black （CB） surface modified with strong nitric acid. Therefore positive cations can be uniformly absorbed by carboxyl groups and precipitated within ...Highly dispersed negative carboxyl groups can be formed on carbon black （CB） surface modified with strong nitric acid. Therefore positive cations can be uniformly absorbed by carboxyl groups and precipitated within a confinement space on modified CB surface to prepare highly dispersed nanomaterials. In this paper, the formation and dispersion status of surface negative carboxyl groups, adsorption status of Ce^3＋, surface confinement nucleation, crystallization and calcination process were studied by EDS, SEM, and laser particle size analysis. The results show that the carboxyl groups formed on modified CB surface are highly dispersed, and Ce^3＋ cations can be uniformly anchored by carboxyl groups. Therefore, highly dispersed Ce^3＋ can react with OH^- within a confinement surface region to form positive nano-Ce（OH）4 nuclei which also can be adsorbed by electrostatic attraction. After independent growth of Ce（OH）4 without agglomeration, highly dispersed CeO2 nanoparticles without agglomeration can be prepared together with the help of effectively isolates by CO2 released in the combustion of CB.展开更多
In this study,aquatic toxic effect of atrazine,and nano-CeO2,the accumulation,reproduction and adsorp-tion of atrazine onto nano-CeO2 and the facilitated transport of atrazine into D.magna by nano-CeO2 were exam-ined....In this study,aquatic toxic effect of atrazine,and nano-CeO2,the accumulation,reproduction and adsorp-tion of atrazine onto nano-CeO2 and the facilitated transport of atrazine into D.magna by nano-CeO2 were exam-ined.The results showed that atrazine concentrations of 3.0,4.0,and 10.0 mg/L exhibited 43%,56%,68% mortali-ties,respectively,which indicated the mortality was 56% while the concentration of nano-CeO2 was 4.0 mg/L.D.magna accumulated considerably more atrazine when exposed to atrazine-contaminated water in the presence of nano-CeO2.At the same time,atrazine and nano-CeO2 yielded a significant reduction of the reproduction rate at all concentrations tested.What is more,the co-exposure of nano-CeO2 and atrazine was observed to significantly de-crease the reproduction rate of D.magna,and atrazine adsorbed on nano-CeO2 quickly.Therefore,attention should be paid to their associations with other contaminants for the risk assessment of nano-CeO2 and it is worthy of notice that the sorption of atrazine on nano-CeO2 would enhance the toxicity of atrazine to D.magna.展开更多
基金This work was supported by the National Key R＆D Program of China （2016YFB0301602） and the National Natural Science Foundation of China （Grant Nos. 21776018 and 21627813）.
文摘Highly dispersed negative carboxyl groups can be formed on carbon black （CB） surface modified with strong nitric acid. Therefore positive cations can be uniformly absorbed by carboxyl groups and precipitated within a confinement space on modified CB surface to prepare highly dispersed nanomaterials. In this paper, the formation and dispersion status of surface negative carboxyl groups, adsorption status of Ce^3＋, surface confinement nucleation, crystallization and calcination process were studied by EDS, SEM, and laser particle size analysis. The results show that the carboxyl groups formed on modified CB surface are highly dispersed, and Ce^3＋ cations can be uniformly anchored by carboxyl groups. Therefore, highly dispersed Ce^3＋ can react with OH^- within a confinement surface region to form positive nano-Ce（OH）4 nuclei which also can be adsorbed by electrostatic attraction. After independent growth of Ce（OH）4 without agglomeration, highly dispersed CeO2 nanoparticles without agglomeration can be prepared together with the help of effectively isolates by CO2 released in the combustion of CB.
基金supported by Chongqing Key Laboratory of Micro/Nano Materials Engineering and Technology (No. KFJJ1106)Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresources and Environmental Protection (No.JLCBE11004)Jiangsu Marine Resources Development Research Institute (No. JSIMR10E04)
文摘In this study,aquatic toxic effect of atrazine,and nano-CeO2,the accumulation,reproduction and adsorp-tion of atrazine onto nano-CeO2 and the facilitated transport of atrazine into D.magna by nano-CeO2 were exam-ined.The results showed that atrazine concentrations of 3.0,4.0,and 10.0 mg/L exhibited 43%,56%,68% mortali-ties,respectively,which indicated the mortality was 56% while the concentration of nano-CeO2 was 4.0 mg/L.D.magna accumulated considerably more atrazine when exposed to atrazine-contaminated water in the presence of nano-CeO2.At the same time,atrazine and nano-CeO2 yielded a significant reduction of the reproduction rate at all concentrations tested.What is more,the co-exposure of nano-CeO2 and atrazine was observed to significantly de-crease the reproduction rate of D.magna,and atrazine adsorbed on nano-CeO2 quickly.Therefore,attention should be paid to their associations with other contaminants for the risk assessment of nano-CeO2 and it is worthy of notice that the sorption of atrazine on nano-CeO2 would enhance the toxicity of atrazine to D.magna.
