Photocatalytic Degradation of Ammonia Nitrogen in Aquaculture Wastewater by Using Nano-TiO2

2011 ◽  
Vol 197-198 ◽  
pp. 774-779
Author(s):  
Peng Fei Zhu ◽  
Xiao Cai Yu ◽  
Qian Du ◽  
Kui Sheng Song ◽  
Zhong Hua He

The nano-TiO2photocatalyst was prepared via sol-gel method, and the crystal structure and surface morphology were characterized by XRD and SEM. The photocatalytic degradation of ammonia-N in aquaculture wastewater was investigated by using nano-TiO2under UV irradiation. In the experiment, the effect of nano-TiO2dosage, ammonia-N initial concentration, pH value, H2O2volume concentration, and reaction time, respectively, on the removal of ammonia-N was investigated. On the basis of the results of these experimental data, an orthogonal array experimental design was used to select more efficient degradation condition. The optimal experimental conditions for photocatalytic degradation of ammonia-N can be stated as follows: when the concentration of ammonia-N was 20 mg/L, nano-TiO2catalyst dosage was 1.2 g/L, the pH value of solution was 5, H2O2volume fraction was 4 %, respectively, if the reaction time may last 3 h, the removal rate of ammonia-N was expected to reach 92.10 %.

2012 ◽  
Vol 610-613 ◽  
pp. 564-568 ◽  
Author(s):  
Kui Sheng Song ◽  
Xiao Cai Yu ◽  
Dong Dong Hu ◽  
Xu Zheng ◽  
Ji Yao Guo

Nano-ZnO photocatalyst was prepared using direct precipitation method .The crystal form, particle size and configuration characterization of the nano-ZnO prepared was characterized by XRD and SEM. The photocatalytic degradation of ammonia-N in aquaculture wastewater was investigated by using nano-ZnO under UV irradiation. The experimental results show that: nano-ZnO dosage, catalytic reaction time, initial ammonia-N concentration, H2O2volume concentration, pH value affect the efficiency of photocatalytic degradation significantly. On the basis of the results of these experimental data, the optimal experimental conditions for photocatalytic degradation of ammonia-N are tried through the orthogonal test. The optimization experimental conditions for photocatalytic degradation of ammonia-N in aquaculture wastewater are as follows, nano-ZnO catalyst dosage was 0.4 g/L, the pH value of solution was 10, H2O2volume fraction was 4 %, respectively, if the reaction time may last 1 h, the removal rate of ammonia-N was expected to reach 86.66 %.


2012 ◽  
Vol 476-478 ◽  
pp. 2001-2004
Author(s):  
Xiao Cai Yu ◽  
Peng Fei Zhu ◽  
Kui Sheng Song ◽  
Dong Dong Hu ◽  
Qian Du

The Fe3+-doped nano-TiO2 catalyst with various amounts of dopant Fe3+ irons was prepared by a sol-gel method. The products were characterized by XRD and SEM. The photocatalytic degradation of ammonia nitrogen in aquaculture wastewater was investigated by using Fe3+-doped nano-TiO2 under UV irradiation. In the experiment, the effect of Fe3+/TiO2 dosage, the ratio of dopant Fe3+, ammonia-N initial concentration, pH value, H2O2 volume concentration, and reaction time, respectively, on the removal of ammonia-N was investigated. The experimental results can be stated as follows: when the ratio of dopant Fe3+ was 0.25% wt, the dosage of Fe3+/TiO2 was 0.7 g/L, the initial concentration of ammonia-N was 10 mg/L, H2O2 volume fraction was 4 %, respectively, if the reaction time may last 4 h, the removal rate of ammonia-N was expected to reach 97.17 %.


2011 ◽  
Vol 197-198 ◽  
pp. 780-785 ◽  
Author(s):  
Xiao Cai Yu ◽  
Qian Du ◽  
Peng Fei Zhu ◽  
Dong Dong Hu ◽  
Li Yang

TiO2 can be used as a photocatalyst because of its semiconductor property. When TiO2 is doped with transition metal ions, its electronic properties may be modified. In this work, nanosized Sn4+-doped TiO2 (TiO2-Sn4+) particles have been synthesized by a sol-gel process at different temperature. Their microstructure and crystal structure depending on the calcination temperatures were investigated using XRD and SEM techniques. The photocatalytic degradation of diesel pollutants in seawater was investigated by using Sn4+-doped nanometer TiO2 under UV irradiation. In the experiment, the effect of different ratio of Sn4+ doped into TiO2, the effect of calcination temperature of Sn-doped nano-TiO2, the effect of Sn4+-doped nanometer TiO2 dosage, pH value and photocatalytic degradation reaction time, respectively, on the removal of diesel pollutants in seawater was investigated. On the basis of the results of these experimental data, the optimal experimental conditions for photocatalytic degradation of diesel are tried through the orthogonal test. The results reveal that when the ratio of Sn4+ doped into TiO2 was 3% wt, the calcination temperature of Sn-doped nano-TiO2 was 400°C, the Sn4+-doped nanometer TiO2 dosage was 1 g/L, pH value was 8 and photocatalytic degradation reaction time was 1.5h, respectively, the removal rate of diesel pollutants in seawater was expected to reach 88.00 %.


2012 ◽  
Vol 476-478 ◽  
pp. 1926-1929
Author(s):  
Xiao Cai Yu ◽  
Dong Dong Hu ◽  
Qian Du ◽  
Xv Zheng ◽  
Ji Yao Guo

Nanoscale titanium dioxide (TiO2) has been fabricated through a sound sol-gel method at room temperature with Tetra-n-butyl Titanate as the precursor, and the particles are characterized by XRD and TEM techniques. The results manifest that the as-prepared TiO2 is amorphous with the anatase structure and its size is around 33.2nm. Five factors, including dosage of TiO2, initial concentration of diesel, pH value, photocatalytic degradation reaction time and the presence of H2O2, are considered in the diesel degradation experiments. An orthogonal test is carried out to optimize the photocatalytic degradation of diesel pollutants based on the single-factor experiments. It reveals that when the dosage of TiO2 is 1.0g/L, the initial concentration of diesel is 0.5g/L, pH value is 6, the reaction time is 4h and the H2O2 dosage is 0.09%, the removal rate of diesel pollutants can up to 88%. Besides, the influence of each factor on removing diesel can be arranged in decreasing order: initial concentration of diesel> photocatalytic reaction time> pH value> TiO2 dosage> H2O2 dosage.


2011 ◽  
Vol 347-353 ◽  
pp. 2351-2355 ◽  
Author(s):  
Xiao Cai Yu ◽  
Peng Fei Zhu ◽  
Min Zhang ◽  
Ji Yao Guo ◽  
Xv Zheng

The Sn4+-doped nano-TiO2 particles with various amounts of dopant Sn4+ irons was prepared by sol-gel method using tetrabutyl titanate(TEOT) as one of the primary raw materials at different calcination temperatures (400-700°C). The products were characterized by XRD and SEM, which revealed that the crystal structure of Sn4+-doped nano-TiO2 changes from anatase to rutile with the calcination temperature increasing, and the nanoparticles diameter was around 10-30 nm. The photocatalytic degradation of ammonia nitrogen in aquaculture wastewater was investigated by using Sn4+-doped nano-TiO2 under UV irradiation. The experimental results can be stated as follows: when the ratio of dopant Sn4+ was 3% wt, the calcination temperature of Sn4+-doped nano-TiO2 was 500 °C, the dosage of Sn4+-doped nano-TiO2 was 0.8 g/L, respectively, if the reaction time may last 4h, the removal rate of ammonia-N was expected to reach 87.13%.


2014 ◽  
Vol 609-610 ◽  
pp. 311-316
Author(s):  
Xiao Cai Yu ◽  
Dong Dong Hu ◽  
Jin Fang Chen ◽  
Xiao Jie Jin ◽  
Xu Zheng

ZnO and Ag-droped ZnO photocatalysts with different Ag loadings (0.5, 1.0, 1.5, 2.0at%) and different calcination temperature (300, 400, 500, 600, 700°C) were synthesized by a sonochemical method. The morphology and crystal pattern of some prepared catalysts were characterized by XRD and SEM techniques which demonstrated that the prepared catalysts were of hexagonal wurtzite structure. Ag loadings, calcination temperature and other factors, dosage of photocatalyst, reaction time and pH value of seawater, were also taken into consideration in the procedure of photocatalytic degradation reaction under UV light. An orthogonal experiment was carried out to investigate the best combination of factors which can reach the best diesel pollution removal rate and the influence order of factors. Reaction time and dosage of catalyst were the most influential factors in this experiment, and the factor of calcination temperature was the weakest influential factor. The removal rate of diesel can up to 78% when the experiment was undertaken under the very conditions: the dosage of catalyst 2.0g/L, reaction time 2.0h, Ag loading of catalyst 1.0 at%, calcinations temperature 400°C and pH value 8.5.


2012 ◽  
Vol 518-523 ◽  
pp. 121-124
Author(s):  
Hong Xia Xia ◽  
Qi Hong Zhu

This paper investigates the effect of Limonite/TiO2 combined microspheres dosage,solution pH, reaction time,light intensity on the removal rate of phenol in source water.Based on the single factor experiment, the experimental conditions are optimized by quadratic regression orthogonal rotation combination design.The quadratic orthogonal regression model of removal rate of phenol(y) to four factors of Limonite/TiO2 combined microspheres dosage(x1),pH(x2),reaction time (x3)and light intensity (x4) is established as Y=88.64+4.43X1+ 6.69X3+3.75X4-4.79X12-13.20X22-4.21X32-2.69X42+8.06X1X2-6.76X1X3-4.45X1X4.It can conclude from the model that when Limonite/TiO2 combined microspheres dosage is 1.5583g,solution pH value is 4.5095,reaction time is 102.12min,light intensity is 1710.8(x10 lux),the yield(y) reaches the maximal(95.83%) and consistent with the confirmatory experiment result..


2011 ◽  
Vol 347-353 ◽  
pp. 733-737 ◽  
Author(s):  
Xiao Cai Yu ◽  
Peng Fei Zhu ◽  
Yue Xia Chen ◽  
Jun Wang ◽  
Zong Fu An

Nano-Sn0.25Ti0.75O2 was prepared with hydrothermal method using tetrabutyl titanate as one of the primary raw materials. The products were characterized by XRD and SEM, which revealed that the crystal structure of Sn4+-doped nano-TiO2 is rutile, and the nanoparticles diameter was 14.49nm. Photocatalytic treatment the machining wastewater containing cadmium ions with the UV excitation by Nano-Sn0.25Ti0.75O2 was investigated. The experimental results show that Nano-Sn0.25Ti0.75O2 can be used as photocatalyst to removal Cd2+ from the wastewater effectively with the UV excitation. The wastewater pH value, the initial concentration of Cd2+, the amount of catalyst,the reaction time and other factors affect the efficiency of photocatalytic treatment significantly. The optimization experimental conditions for photocatalytic treatment wastewater containing cadmium ions are as follows, when the concentration of Cd2+ in the wastewater is 20mg/L, amount of Sn0.25Ti0.75O2 is 2g/L, pH in wastewater is 7 and the photocatalytic reaction time is 2h, the removal rate of Cd2+ from the wastewater is up to 98.4%.


2012 ◽  
Vol 476-478 ◽  
pp. 1939-1942 ◽  
Author(s):  
Dong Dong Hu ◽  
Xiao Cai Yu ◽  
Min Zhang ◽  
Ji Yao Guo ◽  
Xv Zheng

Semiconductor ZnO nanocrystal has been synthesized by a sonochemical method and characterized by XRD and SEM techniques. The results indicate that the as-prepared ZnO is of hexagonal wurtzite structure. The photocatalytic degradation of diesel pollutants in seawater is investigated by utilization of ZnO in simulated diesel-polluted seawater exposed to UV irradiation. In the experiment, the influences of ZnO dosage, initial concentration of diesel, pH value, photocatalytic degradation reaction time and the presence of assistance oxidant peroxide, respectively, on the diesel pollutants removal from seawater are investigated. A systematic optimization study is carried out through a orthogonal test on the basis of the results of the single-factor experiments. It reveals that when the experiment is undertaken under the very condition: the ZnO dosage is 1g/L, the initial concentration of diesel 1g/L, the pH value 7, the reaction time 3h and the concentration of peroxide 0.16%, the removal rate of diesel pollutants in seawater is expected to reach 84 %.


2013 ◽  
Vol 785-786 ◽  
pp. 459-462
Author(s):  
Ji Yao Guo ◽  
Xiao Cai Yu ◽  
Xiao Xv ◽  
Jin Fang Chen ◽  
Yun Qing Liu

Li+-doped nanoTiO2particles with various amounts of dopant Li+irons have been synthesized by a sol-gel process. The products were characterized by XRD and SEM.Which revealed that the crystal structure of Li+-doped nanoTiO2is anatase, and the nanoparticles diameter was 42nm. Five factous, including dosage of Li+-doped nanoTiO2, initial concentration of diesel, pH value , photocatalytic degradetion reaction time and the presence of H2O2, are considered in the diesel degradation experiments. The results manifest that Li+-doped nanoTiO2can be used as photocatalyst to removal diesel pollutants in seawater effectively. When the ratio of Li+doped into TiO2is 1%wt, the calcination temperature of Li-doped nanoTiO2is 500°C, the dosage of the Li+-doped nanometer TiO2is 0.4g/L, the initial concentration of diesel is 0.2g/L, pH value is 7.0, the reaction time is 2.5h and the H2O2dosage is 0.2g/L, the removal rate of diesel pollutants is up to 88.10%.


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