The Bi_4Ti_3O_(12)/g-C_3N_4 composites with microsheet and nanosheet structure were prepared through facile ultrasonic-assisted method. The SEM and TEM results suggested that the nanosheets g-C_3N_4 were stacked on th...The Bi_4Ti_3O_(12)/g-C_3N_4 composites with microsheet and nanosheet structure were prepared through facile ultrasonic-assisted method. The SEM and TEM results suggested that the nanosheets g-C_3N_4 were stacked on the surface of regular Bi_4Ti_3O_(12) sheets. Comparing with pure Bi_4Ti_3O_(12) and g-C_3N_4, the Bi_4Ti_3O_(12)/g-C_3N_4 composites showed significant enhancement in photocatalytic efficiency for the degradation of RhB in solution. With the mass ratio of g-C_3N_4 increasing to 10 wt%, the Bi_4Ti_3O_(12)/g-C_3N_4-10% presented the best photocatalytic activity. Its photocatalysis reaction constant was approximately 2 times higher than the single component Bi_4Ti_3O_(12) or g-C_3N_4. Meanwhile, good stability and durability for the Bi_4Ti_3O_(12)/g-C_3N_4-10% were confirmed by the recycling experiment and FT-IR analysis. The possible mechanism for the improvements was the matched band positions and the effective separation of photo-excited electrons(e-) and holes(h+). Furthermore, based on the results of active species trapping, photo-generated holes(h+) and superoxide radical(·O2-) could be the main radicals in reaction.展开更多
The effect of salinity on biological nitrogen and denitrifying phosphorus removal was investigated in a Modified University of Cape Town(MUCT)system.Removal rates of COD,NH_(4)^(+)-N,NO_(3)^(-)-N,NO_(2)^(-)-N,phosphor...The effect of salinity on biological nitrogen and denitrifying phosphorus removal was investigated in a Modified University of Cape Town(MUCT)system.Removal rates of COD,NH_(4)^(+)-N,NO_(3)^(-)-N,NO_(2)^(-)-N,phosphorus and the sludge characteristics at salt concentrations(0.0,3.2,6.4,11.2 and 16.0 g L^(-1))were analyzed.With the salt concentration increasing,all the COD,NH_(4)^(+)-N,TN and TP removal rates exhibited a trend of decline,and exhibited an initial reduction and subsequent increase at every stage of salt concentration.NH_(4)^(+)-N,TN and TP removal rates were 92.7%,51.5%and 67.2%in 16 g L^(-1) salt concentration,respectively.And they were outperformed the literature reported and acceptable in practical applications.When the salinity of wastewater changed from 0.0 to 16.0 g L^(-1),the biomass yield coefficients increased from 0.0794 to 0.126 g VSS/g COD.Increased salinity had a detrimental effect on phosphorus-accumulating organisms(PAOs)and denitrifying PAOs(DPAOs)(especially DPAOs).Therefore,phosphorus removal gradually depended on PAO.The simultaneous nitrification and denitrification(SND)rate and nitrogen removal rate(including nitrification rate,denitrification rate,and total nitrogen removal rate)gradually decreased with the increased salinity.展开更多
基金Supported by the National Natural Science Foundation of China(51509220)the Natural Science Foundation of Zhejiang Province(LQ14E090003)+1 种基金Ningbo Science and Technology Plan Projects(2014C50007,2014C51003)Ningbo major social development projects(2017C510006)
文摘The Bi_4Ti_3O_(12)/g-C_3N_4 composites with microsheet and nanosheet structure were prepared through facile ultrasonic-assisted method. The SEM and TEM results suggested that the nanosheets g-C_3N_4 were stacked on the surface of regular Bi_4Ti_3O_(12) sheets. Comparing with pure Bi_4Ti_3O_(12) and g-C_3N_4, the Bi_4Ti_3O_(12)/g-C_3N_4 composites showed significant enhancement in photocatalytic efficiency for the degradation of RhB in solution. With the mass ratio of g-C_3N_4 increasing to 10 wt%, the Bi_4Ti_3O_(12)/g-C_3N_4-10% presented the best photocatalytic activity. Its photocatalysis reaction constant was approximately 2 times higher than the single component Bi_4Ti_3O_(12) or g-C_3N_4. Meanwhile, good stability and durability for the Bi_4Ti_3O_(12)/g-C_3N_4-10% were confirmed by the recycling experiment and FT-IR analysis. The possible mechanism for the improvements was the matched band positions and the effective separation of photo-excited electrons(e-) and holes(h+). Furthermore, based on the results of active species trapping, photo-generated holes(h+) and superoxide radical(·O2-) could be the main radicals in reaction.
基金This work was supported by the Zhejiang Provincial Natural Science Foundation of China(LGF20E080003,LQ20E080002)National Natural Science Foundation of China(21808200)+2 种基金Major Social Development Project of Ningbo(2017C510006)the Ningbo Natural Science Foundation of China(2018A61028,202003N4312)BNU Interdisciplinary Research Foundation for the First-Year Doctoral Candidates(No.BNUXKJC1806).
文摘The effect of salinity on biological nitrogen and denitrifying phosphorus removal was investigated in a Modified University of Cape Town(MUCT)system.Removal rates of COD,NH_(4)^(+)-N,NO_(3)^(-)-N,NO_(2)^(-)-N,phosphorus and the sludge characteristics at salt concentrations(0.0,3.2,6.4,11.2 and 16.0 g L^(-1))were analyzed.With the salt concentration increasing,all the COD,NH_(4)^(+)-N,TN and TP removal rates exhibited a trend of decline,and exhibited an initial reduction and subsequent increase at every stage of salt concentration.NH_(4)^(+)-N,TN and TP removal rates were 92.7%,51.5%and 67.2%in 16 g L^(-1) salt concentration,respectively.And they were outperformed the literature reported and acceptable in practical applications.When the salinity of wastewater changed from 0.0 to 16.0 g L^(-1),the biomass yield coefficients increased from 0.0794 to 0.126 g VSS/g COD.Increased salinity had a detrimental effect on phosphorus-accumulating organisms(PAOs)and denitrifying PAOs(DPAOs)(especially DPAOs).Therefore,phosphorus removal gradually depended on PAO.The simultaneous nitrification and denitrification(SND)rate and nitrogen removal rate(including nitrification rate,denitrification rate,and total nitrogen removal rate)gradually decreased with the increased salinity.
