Based on wet air oxidation (WAO) and Fenton reagent, this paper raised a new low pressure wet catalytic oxidation (LPWCO) which requires low pressure for the treatment of highly concentrated and refractory organic was...Based on wet air oxidation (WAO) and Fenton reagent, this paper raised a new low pressure wet catalytic oxidation (LPWCO) which requires low pressure for the treatment of highly concentrated and refractory organic wastewater. Compared with general wet air oxidation, the pressure of the treatment(0 1—0 6MPa) is only one of tens to percentage of latter (3 5—10MPa). In addition, its temperature is no more than 180℃. Compared with Fenton reagent, while H 2O 2/COD(weight ratio) is less than 1 2, the removal of COD in the treatment is over twenty percents more than Fenton's even the value of COD is more than 14000mg/L. In this paper, the effect factor of COD removal and the mechanism of this treatment were studied. The existence of synergistic effect (catalytic oxidation and carbonization) for COD removal in H 2SO 4 Fenton reagent system under the condition of applied pressure and heating (0 1—0 6MPa, 104—165℃) was verified. The best condition of this disposal are as follows: H 2O 2/COD (weight ratio)=0 2—1 0, Fe 2+ 0 6×10 -3 mol, H 2SO 4 0 5mol, COD>1×10 4mg/L, the operating pressure is 0 1—0 6MPa and temperature is 104—165℃. This method suits to dispose the high concentrated refractory wastewater, especially to the wastewater containing H 2SO 4 produced in the manufacture of pesticide, dyestuff and petrochemical works.展开更多
In this paper,the collective effects of combining heterogeneous Ag/TiO2 nanocomposite catalyst with the byproducts（primarily the irradiation and the O3 species） of an atmospheric pressure plasma jet（APPJ） system o...In this paper,the collective effects of combining heterogeneous Ag/TiO2 nanocomposite catalyst with the byproducts（primarily the irradiation and the O3 species） of an atmospheric pressure plasma jet（APPJ） system on the degradation of methyl orange（MO） were explored.The heterostructured Ag/TiO2 nanocomposite was achieved via decorating the Ag quantum dots（QDs） on the commercially available TiO_2catalyst（P25） through a hydrothermal method.The x-ray diffraction analysis of the nanocomposite catalyst showed the diffraction peaks at 44.3°,64.4°,and 77.5°,corresponding to the Ag planes of（200）,（220） and（311）,respectively.The high resolution transmission electron microscope characterization of the nanocomposite catalyst indicated that the Ag QDs with an average diameter of 5 nm were homogeneously distributed on the P25 surface.The experimental results on the MO photodegradation showed that the APPJ irradiation had a marginal effect on the cleavage of the MO molecules.When the Ag/TiO2 nanocomposite catalyst was used,the photodegradation rate of MO increased about 5 times.When both the APPJ byproducts and the Ag/TiO2 nanocomposite catalyst were used,however,over 90% of the MO in the tested solution was cleaved within 15 min,and the energy efficiency was about 0.6 g/k W h.Moreover,an optimal Ag dosage value was determined（6 wt%）.The catalytic results indicated that combining the DBD plasma byproducts with heterogeneous nanocomposite catalysts may be an effect protocol for decreasing the application cost of the DBD system and mitigating the environment pollution by organic dyes in the textile industry.展开更多
To develop a depth filter based on the electrostatic adsorption principle, positively charged microporous ceramic membrane was prepared from a diatomaceous earth ceramic membrane.The internal surface of the highly por...To develop a depth filter based on the electrostatic adsorption principle, positively charged microporous ceramic membrane was prepared from a diatomaceous earth ceramic membrane.The internal surface of the highly porous ceramic membrane was coated with uniformly distributed electropositive nano-Y2O3 coating. The dye removal performance was evaluated through pressurized filtration tests using Titan Yellow aqueous solution. It showed that positively charged microporous ceramic membrane exhibited a flow rate of 421 L/（m^2·hr） under the trans-membrane pressure of 0.03 bar. Moreover it could effectively remove Titan Yellow with feed concentration of 10 mg/L between pH 3 to 8. The removal rate increased with the enhancement of the surface charge properties with a maximum rejection of 99.6%. This study provides a new and feasible method of removing organic dyes in wastewater. It is convinced that there will be a broad market for the application of charged ceramic membrane in the field of dye removal or recovery from industry wastewater.展开更多
文摘Based on wet air oxidation (WAO) and Fenton reagent, this paper raised a new low pressure wet catalytic oxidation (LPWCO) which requires low pressure for the treatment of highly concentrated and refractory organic wastewater. Compared with general wet air oxidation, the pressure of the treatment(0 1—0 6MPa) is only one of tens to percentage of latter (3 5—10MPa). In addition, its temperature is no more than 180℃. Compared with Fenton reagent, while H 2O 2/COD(weight ratio) is less than 1 2, the removal of COD in the treatment is over twenty percents more than Fenton's even the value of COD is more than 14000mg/L. In this paper, the effect factor of COD removal and the mechanism of this treatment were studied. The existence of synergistic effect (catalytic oxidation and carbonization) for COD removal in H 2SO 4 Fenton reagent system under the condition of applied pressure and heating (0 1—0 6MPa, 104—165℃) was verified. The best condition of this disposal are as follows: H 2O 2/COD (weight ratio)=0 2—1 0, Fe 2+ 0 6×10 -3 mol, H 2SO 4 0 5mol, COD>1×10 4mg/L, the operating pressure is 0 1—0 6MPa and temperature is 104—165℃. This method suits to dispose the high concentrated refractory wastewater, especially to the wastewater containing H 2SO 4 produced in the manufacture of pesticide, dyestuff and petrochemical works.
基金the support from National Natural Science Foundation of China under Grant No.11175157the Zhejiang Natural Science Foundations of China under No.LY16A050002+1 种基金521 Talent Project of Zhejiang Sci-Tech Universitythe Young Researchers Foundations of Zhejiang Provincial Top Key Academic Discipline of Chemical Engineering and Technology
文摘In this paper,the collective effects of combining heterogeneous Ag/TiO2 nanocomposite catalyst with the byproducts（primarily the irradiation and the O3 species） of an atmospheric pressure plasma jet（APPJ） system on the degradation of methyl orange（MO） were explored.The heterostructured Ag/TiO2 nanocomposite was achieved via decorating the Ag quantum dots（QDs） on the commercially available TiO_2catalyst（P25） through a hydrothermal method.The x-ray diffraction analysis of the nanocomposite catalyst showed the diffraction peaks at 44.3°,64.4°,and 77.5°,corresponding to the Ag planes of（200）,（220） and（311）,respectively.The high resolution transmission electron microscope characterization of the nanocomposite catalyst indicated that the Ag QDs with an average diameter of 5 nm were homogeneously distributed on the P25 surface.The experimental results on the MO photodegradation showed that the APPJ irradiation had a marginal effect on the cleavage of the MO molecules.When the Ag/TiO2 nanocomposite catalyst was used,the photodegradation rate of MO increased about 5 times.When both the APPJ byproducts and the Ag/TiO2 nanocomposite catalyst were used,however,over 90% of the MO in the tested solution was cleaved within 15 min,and the energy efficiency was about 0.6 g/k W h.Moreover,an optimal Ag dosage value was determined（6 wt%）.The catalytic results indicated that combining the DBD plasma byproducts with heterogeneous nanocomposite catalysts may be an effect protocol for decreasing the application cost of the DBD system and mitigating the environment pollution by organic dyes in the textile industry.
基金supported by the National Natural Science Foundation of China (No. 51202292)
文摘To develop a depth filter based on the electrostatic adsorption principle, positively charged microporous ceramic membrane was prepared from a diatomaceous earth ceramic membrane.The internal surface of the highly porous ceramic membrane was coated with uniformly distributed electropositive nano-Y2O3 coating. The dye removal performance was evaluated through pressurized filtration tests using Titan Yellow aqueous solution. It showed that positively charged microporous ceramic membrane exhibited a flow rate of 421 L/（m^2·hr） under the trans-membrane pressure of 0.03 bar. Moreover it could effectively remove Titan Yellow with feed concentration of 10 mg/L between pH 3 to 8. The removal rate increased with the enhancement of the surface charge properties with a maximum rejection of 99.6%. This study provides a new and feasible method of removing organic dyes in wastewater. It is convinced that there will be a broad market for the application of charged ceramic membrane in the field of dye removal or recovery from industry wastewater.
