Aqueous dye solutions were irradiated by Co γ-rays or electron beams and the irradiation induced decolora- 60 tion and degradation of the dyes were studied with UV/visuable absorption spectra and pH value measurement...Aqueous dye solutions were irradiated by Co γ-rays or electron beams and the irradiation induced decolora- 60 tion and degradation of the dyes were studied with UV/visuable absorption spectra and pH value measurement. In addition, (Chemical oxygen demand, COD) removal rate of the irradiated solutions, and synergetic effect of hy- drogen peroxide and the irradiations, were investigated, The results show that the combination of radiation tech- nology and other wastewater treatment can be a promising process for treating dyeing and finishing waste effluents.展开更多
In this study, orange G dye was efficiently removed from aqueous solution by ultraflltration (UF) membrane separation enhanced with activated carbon adsorption. The powdered activated carbon (PAC) was deposited on...In this study, orange G dye was efficiently removed from aqueous solution by ultraflltration (UF) membrane separation enhanced with activated carbon adsorption. The powdered activated carbon (PAC) was deposited onto the UF membrane surface, forming an intact filter cake. The enhanced UF process simultaneously exploited the high water permeation flux of porous membrane and the high adsorption ability of PAC toward dye molecules. The influencing factors on the dye removal were investigated. The results indicated that with sufficient PAC incorporation, the formation of intact PAC filtration cake led to nearly complete rejection for dye solution under opti-mized dye concentration and operation pressure, without large sacnticlng the permeation tlux ot the filtration process. Typically, the dye rejection ratio increased from 43.6% for single UF without adsorption to nearly 100% for the enhanced UF process, achieving long time continuous treatment with water permeation flux of 47 L·m^-2·h^-1. The present study demonstrated that adsorption enhanced UF may be a feasible method for the dye wastewater treatment.展开更多
Photocatalytic activity of TiO2 nanopowders of anatase modification with various particle sizes and specific surface areas has been studied in the process of photocatalytic decolorization of aqueous solutions of methy...Photocatalytic activity of TiO2 nanopowders of anatase modification with various particle sizes and specific surface areas has been studied in the process of photocatalytic decolorization of aqueous solutions of methylene blue and direct blue 2C azodyes. By means of scanning electron microscopy and low-temperature N2 adsorption method, it was found that TiO2 nanopowders have the particles size of 5-120 nm with the specific surface area of 15-120 m2·g^-1. The used TiO2 samples are characterized by mesoporous structures with average pore size of 4.3-14.9 nm. The photocatalytic activity of TiO2 was evaluated via decolorization of azodyes solutions. It was shown that the efficiency of decolorization symbatically changes with the dye adsorption value on TiO2 surface and the degree of decolorization rises when the surface area of TiO2 nanopowders increases. It was found that TiO2 photocatalytic activity essentially depends on adsorption interactions between the dye molecules and catalytic active centers on TiO2 surface, and these interactions, in turn, are greatly affected by pH of the solution.展开更多
The photodegradation has been widely used in water and waste water treatment of all the methods like froth flotation coagulation etc., photodegradation appears to offer the best prospects for overall treatment of dyes...The photodegradation has been widely used in water and waste water treatment of all the methods like froth flotation coagulation etc., photodegradation appears to offer the best prospects for overall treatment of dyestuff effulent. Photodegradation of aniline blue and crystal violet dyes from aqueous solutions of their binary mixture was carried out using TiO2 as photocatalyst. By carrying out photodegradation, varying the experimental parameters, the optimum conditions required for maximum degradation was found out. The photodegradation of dye was carried out using different sources of energy like solar radiation and microwave radiation. The degradation studies were carried out at temperatures 25 ℃, 35 ℃ and 45 ℃ so as to calculate the rate constant and activation parameters. Both energy sources are equivalent in causing degradation in all respects except time and dose of photo catalyst. Time required is less for microwave than solar radiation, but dose of photo catalyst needed was high for microwave radiation. These results will be helpful in designing effluent treatment plants in industries.展开更多
Cobalt tetra(2,4-dichloro-1,3,5-triazine)aminophthalocyanine (CoPc) was immobilized covalently on activated carbon fiber (ACF) felt to obtain CoPc-modified ACF (CoPc-ACF) catalyst, and an electrocatalytic oxid...Cobalt tetra(2,4-dichloro-1,3,5-triazine)aminophthalocyanine (CoPc) was immobilized covalently on activated carbon fiber (ACF) felt to obtain CoPc-modified ACF (CoPc-ACF) catalyst, and an electrocatalytic oxidation system using CoPc-ACF as the anode was constructed. The electrocatalytic oxidation of Acid Red 1 (ARI) was investigated in aqueous solution by an UV-vis spectrophotometer and UPLC. The results indicated that AR1 could be eliminated efficiently in this electrocatalytic oxidation system. In addition, the results of FTIR, TOC and GC-MS suggested that the electrocatalytic oxidation experienced the decoloration achieved by destroying the azo linkage and the further mineralization due to the cleavages of benzene ring and naphthalene ring. The intermediates were mainly small molecular compounds such as maleic acid and succinic acid, etc. Re- petitive tests showed that CoPc-ACF can maintain high electrocatalytic activity over several cycles. The further EPR spin-trap experiments indicated that the hydroxyl radicals did not dominate the reaction in this electrocatalytic system, which was com- pletely different from the traditional electro-Fenton system. Based on the non-radical reaction mechanism, the CoPc-modified ACF electrocatalyst has potential application in treating actual dyestuffs wastewaters, which are accompanied with high concentration of hydroxyl radical scavengers such as chlorine ions and additives in the textile printing and dyeing industry.展开更多
文摘Aqueous dye solutions were irradiated by Co γ-rays or electron beams and the irradiation induced decolora- 60 tion and degradation of the dyes were studied with UV/visuable absorption spectra and pH value measurement. In addition, (Chemical oxygen demand, COD) removal rate of the irradiated solutions, and synergetic effect of hy- drogen peroxide and the irradiations, were investigated, The results show that the combination of radiation tech- nology and other wastewater treatment can be a promising process for treating dyeing and finishing waste effluents.
基金Supported by Drug Separation and Purification Project in Programme for Development of Novel Drug (2009ZX09301-008)the Program of Introducing Talents of Discipline to Universities (B06006)State Key Laboratory of Precision Measuring Technology and Instruments (Tianjin University)
文摘In this study, orange G dye was efficiently removed from aqueous solution by ultraflltration (UF) membrane separation enhanced with activated carbon adsorption. The powdered activated carbon (PAC) was deposited onto the UF membrane surface, forming an intact filter cake. The enhanced UF process simultaneously exploited the high water permeation flux of porous membrane and the high adsorption ability of PAC toward dye molecules. The influencing factors on the dye removal were investigated. The results indicated that with sufficient PAC incorporation, the formation of intact PAC filtration cake led to nearly complete rejection for dye solution under opti-mized dye concentration and operation pressure, without large sacnticlng the permeation tlux ot the filtration process. Typically, the dye rejection ratio increased from 43.6% for single UF without adsorption to nearly 100% for the enhanced UF process, achieving long time continuous treatment with water permeation flux of 47 L·m^-2·h^-1. The present study demonstrated that adsorption enhanced UF may be a feasible method for the dye wastewater treatment.
文摘Photocatalytic activity of TiO2 nanopowders of anatase modification with various particle sizes and specific surface areas has been studied in the process of photocatalytic decolorization of aqueous solutions of methylene blue and direct blue 2C azodyes. By means of scanning electron microscopy and low-temperature N2 adsorption method, it was found that TiO2 nanopowders have the particles size of 5-120 nm with the specific surface area of 15-120 m2·g^-1. The used TiO2 samples are characterized by mesoporous structures with average pore size of 4.3-14.9 nm. The photocatalytic activity of TiO2 was evaluated via decolorization of azodyes solutions. It was shown that the efficiency of decolorization symbatically changes with the dye adsorption value on TiO2 surface and the degree of decolorization rises when the surface area of TiO2 nanopowders increases. It was found that TiO2 photocatalytic activity essentially depends on adsorption interactions between the dye molecules and catalytic active centers on TiO2 surface, and these interactions, in turn, are greatly affected by pH of the solution.
文摘The photodegradation has been widely used in water and waste water treatment of all the methods like froth flotation coagulation etc., photodegradation appears to offer the best prospects for overall treatment of dyestuff effulent. Photodegradation of aniline blue and crystal violet dyes from aqueous solutions of their binary mixture was carried out using TiO2 as photocatalyst. By carrying out photodegradation, varying the experimental parameters, the optimum conditions required for maximum degradation was found out. The photodegradation of dye was carried out using different sources of energy like solar radiation and microwave radiation. The degradation studies were carried out at temperatures 25 ℃, 35 ℃ and 45 ℃ so as to calculate the rate constant and activation parameters. Both energy sources are equivalent in causing degradation in all respects except time and dose of photo catalyst. Time required is less for microwave than solar radiation, but dose of photo catalyst needed was high for microwave radiation. These results will be helpful in designing effluent treatment plants in industries.
基金supported by the National Natural Science Foundation of China(51133006,51103133,51003096)Program for Changjiang Scholars and Innovative Research Team in University(0654)Textile Vision Science & Education Fund and Science Foundation of Zhejiang SciTech University(1001803-Y)
文摘Cobalt tetra(2,4-dichloro-1,3,5-triazine)aminophthalocyanine (CoPc) was immobilized covalently on activated carbon fiber (ACF) felt to obtain CoPc-modified ACF (CoPc-ACF) catalyst, and an electrocatalytic oxidation system using CoPc-ACF as the anode was constructed. The electrocatalytic oxidation of Acid Red 1 (ARI) was investigated in aqueous solution by an UV-vis spectrophotometer and UPLC. The results indicated that AR1 could be eliminated efficiently in this electrocatalytic oxidation system. In addition, the results of FTIR, TOC and GC-MS suggested that the electrocatalytic oxidation experienced the decoloration achieved by destroying the azo linkage and the further mineralization due to the cleavages of benzene ring and naphthalene ring. The intermediates were mainly small molecular compounds such as maleic acid and succinic acid, etc. Re- petitive tests showed that CoPc-ACF can maintain high electrocatalytic activity over several cycles. The further EPR spin-trap experiments indicated that the hydroxyl radicals did not dominate the reaction in this electrocatalytic system, which was com- pletely different from the traditional electro-Fenton system. Based on the non-radical reaction mechanism, the CoPc-modified ACF electrocatalyst has potential application in treating actual dyestuffs wastewaters, which are accompanied with high concentration of hydroxyl radical scavengers such as chlorine ions and additives in the textile printing and dyeing industry.