MnO2-10aded D301 weak basic anion exchange resin has been used as adsorbent to simultaneously remove lead and cadmium ions from aqueous solution.The effects of adsorbent dosage,solution pH and the coexistent ions on t...MnO2-10aded D301 weak basic anion exchange resin has been used as adsorbent to simultaneously remove lead and cadmium ions from aqueous solution.The effects of adsorbent dosage,solution pH and the coexistent ions on the adsorption were investigated.Experimental results showed that with the adsorbent dosage more than 0.6 g/L,both Pb^2+and Cd^2+were simultaneously removed at pH range 5-6.Except for HPO4^2-,the high concentration coexistent ions such as Na^+,K^+,Cl^-,NO3^-,SO4^2-and HCO3^-,showed no significant effect on the removal efficiency of both Pb^2+and Cd^2+under the experimental conditions.The coexistence of Mg^2+,Ca^2+caused the reduction of Cd^2+removal,but not for Pb^2+.The adsorption equilibrium for Pb^2+and Cd^2+could be excellently described by the Langmuir isotherm model with R^2〉0.99.The maximum adsorption capacity was calculated as 80.64 mg/g for Pb^2+and 21.45 mg/g for Cd^2+.The adsorption processes followed the pseudo first-order kinetics model.MnO2-loaded D301 resin has been shown to have a potential to be used as an effective adsorbent for simultaneous removal of lead and cadmium ions from aqueous solution.展开更多
The adsorption properties of Cu 2＋ -loaded montmorillonite clays （MMT-Cu） for Escherichia coli K 88 as a function of time,bacteria concentrations,pH,ionic strength and temperature were investigated.The results show...The adsorption properties of Cu 2＋ -loaded montmorillonite clays （MMT-Cu） for Escherichia coli K 88 as a function of time,bacteria concentrations,pH,ionic strength and temperature were investigated.The results showed that the bacteria adsorption onto MMT-Cu surface reached equilibrium after 90 min.The percentages of E.coli K 88 adsorbed onto the surfaces of MMT-Cu and montmorillonite clays （MMT） at equilibrium were 88.9% and 56.5%,respectively.Scanning electron microscopy revealed that a lot of E.coli K 88 adhered to the surface of MMT-Cu.The zeta potential of MMT-Cu was relatively high as compared to that of MMT.The adsorptive ability of MMT-Cu for E.coli K 88 was higher than that of MMT （P 0.05）.Moreover,pH,ionic strength and temperature produced a strong influence on the extent of E.coli K 88 adsorption to surface of MMT-Cu and MMT.The mechanism of adsorption of E.coli onto MMT-Cu may involve electrostatic attraction and physiochemical properties of bacterial cell walls and minerals surfaces.展开更多
Titanium dioxide （TiO2） loaded tungsten trioxide （WO3） composite films are prepared by an E-beam vapor system. Associated with the existence of a heterojunction at the interface of TiO2 and WO3, the prepared TiO2-...Titanium dioxide （TiO2） loaded tungsten trioxide （WO3） composite films are prepared by an E-beam vapor system. Associated with the existence of a heterojunction at the interface of TiO2 and WO3, the prepared TiO2-WO3 composite film shows enhanced photocurrent density, four times than the pure WO3 film illuminated under xenon lamp, and higher incident-photon-to-current conversion e^ciency. By varying the initial TiO2 film thickness, such composite structures could be optimized to obtain the highest photocurrent density. We believe that thin TiO2 films improve the light response and increase the surface roughness of WO3 films. Furthermore, the existence of the heterojunction results in the e^cient charge carriers＇ separation, transfer process, and a lower recombination of electron-hole pairs, which is beneficial for the enhancement of photocurrent density.展开更多
基金supported by the National Mega-Project of Science and Technology of China(No.2008ZX07421-002)the International Cooperation Project of Chinese Ministry of Science and Technology(No.2007DFR90050)
文摘MnO2-10aded D301 weak basic anion exchange resin has been used as adsorbent to simultaneously remove lead and cadmium ions from aqueous solution.The effects of adsorbent dosage,solution pH and the coexistent ions on the adsorption were investigated.Experimental results showed that with the adsorbent dosage more than 0.6 g/L,both Pb^2+and Cd^2+were simultaneously removed at pH range 5-6.Except for HPO4^2-,the high concentration coexistent ions such as Na^+,K^+,Cl^-,NO3^-,SO4^2-and HCO3^-,showed no significant effect on the removal efficiency of both Pb^2+and Cd^2+under the experimental conditions.The coexistence of Mg^2+,Ca^2+caused the reduction of Cd^2+removal,but not for Pb^2+.The adsorption equilibrium for Pb^2+and Cd^2+could be excellently described by the Langmuir isotherm model with R^2〉0.99.The maximum adsorption capacity was calculated as 80.64 mg/g for Pb^2+and 21.45 mg/g for Cd^2+.The adsorption processes followed the pseudo first-order kinetics model.MnO2-loaded D301 resin has been shown to have a potential to be used as an effective adsorbent for simultaneous removal of lead and cadmium ions from aqueous solution.
基金supported by the National Natural Science Foundation of China (No.30471255)the Program for New Century Excellent Talents in University(No.NCET-06-0913)
文摘The adsorption properties of Cu 2＋ -loaded montmorillonite clays （MMT-Cu） for Escherichia coli K 88 as a function of time,bacteria concentrations,pH,ionic strength and temperature were investigated.The results showed that the bacteria adsorption onto MMT-Cu surface reached equilibrium after 90 min.The percentages of E.coli K 88 adsorbed onto the surfaces of MMT-Cu and montmorillonite clays （MMT） at equilibrium were 88.9% and 56.5%,respectively.Scanning electron microscopy revealed that a lot of E.coli K 88 adhered to the surface of MMT-Cu.The zeta potential of MMT-Cu was relatively high as compared to that of MMT.The adsorptive ability of MMT-Cu for E.coli K 88 was higher than that of MMT （P 0.05）.Moreover,pH,ionic strength and temperature produced a strong influence on the extent of E.coli K 88 adsorption to surface of MMT-Cu and MMT.The mechanism of adsorption of E.coli onto MMT-Cu may involve electrostatic attraction and physiochemical properties of bacterial cell walls and minerals surfaces.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11174137,11474215 and 21204058the Natural Science Foundation for the Youth of Jiangsu Province under Grant No BK20130284the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Titanium dioxide （TiO2） loaded tungsten trioxide （WO3） composite films are prepared by an E-beam vapor system. Associated with the existence of a heterojunction at the interface of TiO2 and WO3, the prepared TiO2-WO3 composite film shows enhanced photocurrent density, four times than the pure WO3 film illuminated under xenon lamp, and higher incident-photon-to-current conversion e^ciency. By varying the initial TiO2 film thickness, such composite structures could be optimized to obtain the highest photocurrent density. We believe that thin TiO2 films improve the light response and increase the surface roughness of WO3 films. Furthermore, the existence of the heterojunction results in the e^cient charge carriers＇ separation, transfer process, and a lower recombination of electron-hole pairs, which is beneficial for the enhancement of photocurrent density.
