The photocatalytic degradation of norfloxacin by bismuth tungstate(Bi2WO6)with different hierarchical architectures wasinvestigated under visible light irradiation.Bi2WO6was prepared by hydrothermal method with the re...The photocatalytic degradation of norfloxacin by bismuth tungstate(Bi2WO6)with different hierarchical architectures wasinvestigated under visible light irradiation.Bi2WO6was prepared by hydrothermal method with the reaction solution pH rangingfrom4to11.The relatively ultrathin Bi2WO6nanoflakes prepared at pH4showed excellent adsorption and photodegradationefficiency towards norfloxacin.The characterization results showed that Bi2WO6prepared at pH4had a larger specific area andfaster photo-generated carrier separation rate.The decay rate reached the maximum in weak alkaline reaction solution,which couldbe attributed to the presence of moderate OH-anions.The present study demonstrated that the smaller size of Bi2WO6could be anefficient photocatalyst on the degradation of norfloxacin in the aquatic environment.展开更多
An enriched and domesticated bacteria consortium of sulfate-reducing bacteria(SRB)was used to treat wastewater from zinc pyrithione(ZPT)production,and the effects of different reaction parameters on sulfate reduction ...An enriched and domesticated bacteria consortium of sulfate-reducing bacteria(SRB)was used to treat wastewater from zinc pyrithione(ZPT)production,and the effects of different reaction parameters on sulfate reduction and zinc precipitation were evaluated.The single-factor experimental results showed that the removal rates of Zn2+and24SO?decreased with an increased ZPT concentration ranging from3.0to5.0mg/L.Zn2+and24SO?in wastewater were effectively removed under the conditions of30?35°C,pH7?8and an inoculum concentration of10%?25%.The presence of Fe0in the SRB system enhanced Zn2+and24SO?removal and may increase the resistance of SRB to the toxicity of Zn2+and ZPT in wastewater.A Box?Behnken design was used to evaluate the influence of the main operating parameters on the removal rate of24SO?.The optimum parameter values were found to be pH7.45,33.61°C and ZPT concentration of0.62mg/L,and the removal rate of24SO?reached a maximum of91.62%under these optimum conditions.展开更多
Canopy exchanges of H^+ and N (NH4^+-N, NO3^--N) and other major ions were evaluated and quantified In twolayer canopies based on throughfall measurements in Shaoshan Forest during the period 2000-2002, central-so...Canopy exchanges of H^+ and N (NH4^+-N, NO3^--N) and other major ions were evaluated and quantified In twolayer canopies based on throughfall measurements in Shaoshan Forest during the period 2000-2002, central-south China, The collected annual rainfall, throughfall, and sub-throughfall were 1 401, 1 191, and 1 084 mm/year, respectively. Fifteen percent and 8% of rainfall (or 9% of throughfall) were intercepted by the top canopy and sub-canopy layers, respectively, The foliar leaching of base cations from the top canopy was significantly higher than that from the sub-canopy, and the latter accounted for 25% of the former. The uptake of H^+ and NH4^+ was significantly higher in the top canopy than in the sub-canopy, indicating that the canopy buffering capacity in the top canopy was stronger than the sub-canopy; Mg^2+ can be absorbed from water flux on the sub-canopy foliar surfaces to compensate for the Mg deficit in the forest soil during the growing season,展开更多
基金Projects(51579096,51222805,51521006,51508175) supported by the National Natural Science Foundation of ChinaProject supported by the National Program for Support of Top-Notch Young Professionals of China+1 种基金Project(NCET–11–0129) supported by the Program for New Century Excellent Talents in University from the Ministry of Education of ChinaProject(CX2015B095) supported by the Hunan Province Innovation Foundation for Postgraduate,China
文摘The photocatalytic degradation of norfloxacin by bismuth tungstate(Bi2WO6)with different hierarchical architectures wasinvestigated under visible light irradiation.Bi2WO6was prepared by hydrothermal method with the reaction solution pH rangingfrom4to11.The relatively ultrathin Bi2WO6nanoflakes prepared at pH4showed excellent adsorption and photodegradationefficiency towards norfloxacin.The characterization results showed that Bi2WO6prepared at pH4had a larger specific area andfaster photo-generated carrier separation rate.The decay rate reached the maximum in weak alkaline reaction solution,which couldbe attributed to the presence of moderate OH-anions.The present study demonstrated that the smaller size of Bi2WO6could be anefficient photocatalyst on the degradation of norfloxacin in the aquatic environment.
基金Project(2015DFG92750)supported by the International S&T Cooperation Program of ChinaProjects(51278464,51478172)supported by the National Natural Science Foundation of ChinaProject(2014GK1012)supported by the Department of Science and Technology of Hunan Province,China
文摘An enriched and domesticated bacteria consortium of sulfate-reducing bacteria(SRB)was used to treat wastewater from zinc pyrithione(ZPT)production,and the effects of different reaction parameters on sulfate reduction and zinc precipitation were evaluated.The single-factor experimental results showed that the removal rates of Zn2+and24SO?decreased with an increased ZPT concentration ranging from3.0to5.0mg/L.Zn2+and24SO?in wastewater were effectively removed under the conditions of30?35°C,pH7?8and an inoculum concentration of10%?25%.The presence of Fe0in the SRB system enhanced Zn2+and24SO?removal and may increase the resistance of SRB to the toxicity of Zn2+and ZPT in wastewater.A Box?Behnken design was used to evaluate the influence of the main operating parameters on the removal rate of24SO?.The optimum parameter values were found to be pH7.45,33.61°C and ZPT concentration of0.62mg/L,and the removal rate of24SO?reached a maximum of91.62%under these optimum conditions.
文摘Canopy exchanges of H^+ and N (NH4^+-N, NO3^--N) and other major ions were evaluated and quantified In twolayer canopies based on throughfall measurements in Shaoshan Forest during the period 2000-2002, central-south China, The collected annual rainfall, throughfall, and sub-throughfall were 1 401, 1 191, and 1 084 mm/year, respectively. Fifteen percent and 8% of rainfall (or 9% of throughfall) were intercepted by the top canopy and sub-canopy layers, respectively, The foliar leaching of base cations from the top canopy was significantly higher than that from the sub-canopy, and the latter accounted for 25% of the former. The uptake of H^+ and NH4^+ was significantly higher in the top canopy than in the sub-canopy, indicating that the canopy buffering capacity in the top canopy was stronger than the sub-canopy; Mg^2+ can be absorbed from water flux on the sub-canopy foliar surfaces to compensate for the Mg deficit in the forest soil during the growing season,