Magnetic Fe3O4 nanomagnetic particles were synthesized by the titration co-precipitation method followed by coating by the sol-gel method with Titamiun dioxide. The photocalytic activities of different synthesized TiO...Magnetic Fe3O4 nanomagnetic particles were synthesized by the titration co-precipitation method followed by coating by the sol-gel method with Titamiun dioxide. The photocalytic activities of different synthesized TiO2/Fe304 nanomagnetic particles with different molar ratios of TiO2 to Fe3O4 were investigated by the reduction of phosphate, nitrate and decolorizing of methyl blue solutions. X-ray diffraction was used to characterize the size, composition and morphology of the synthesized particles. The results obtained from these experiments indicate an increase in the photocatalytic activity as the amount of TiO2 coating increases. The results show a higher activity of the synthesized particles in the removal of phosphate, nitrate and methyl blue, which can be achieved at early reaction periods at about 70-80%. The activities were higher when the particles were incubated without UV illumination. This study shows that TiO2/Fe3O4 particles are effective in phosphate, nitrate and methyl blue removal in wastewater treatment.展开更多
The adsorption of methyl orange onto ultrafine coal powder （UCP） and modified ultrafine coal powder （MUCP） from aqueous solutions were studied, in which the influence of contact time, dosage, temperature, pH, and ...The adsorption of methyl orange onto ultrafine coal powder （UCP） and modified ultrafine coal powder （MUCP） from aqueous solutions were studied, in which the influence of contact time, dosage, temperature, pH, and methyl orange concentration in the solution were investigated. The adsorption kinetics of methyl orange by UCP and MUCP can be described by the Lagergren first-order and pseudo second-order kinetic models, respectively. The adsorption isotherms of methyl orange onto MUCP at 303, 313 and 323 K follow the Freundlich and Langmuir isotherm equation. Values of △G^0 for methyl orange adsorption onto MUCP are -22.55, -23.10 and -23.79 kJ·mol^-1 at 303, 313, and 323 K, respectively. The values of △H^0 and △S^0 are -3.74 kJ· mol^-1 and 61.99 J·mol^-1, respectively. The adsorption process is spontaneous and exothermic.展开更多
High strength refractory organic stream is produced during the production of 2-phenylamino-3-methyl-6-di-n-butylaminofluoran （One Dye Black 2, abbr. ODB 2）, a novel heat-sensitive material with a promising market. I...High strength refractory organic stream is produced during the production of 2-phenylamino-3-methyl-6-di-n-butylaminofluoran （One Dye Black 2, abbr. ODB 2）, a novel heat-sensitive material with a promising market. In this study, a combination of acidificationprecipitation, primary biological treatment, Fenton＇s oxidation and another biological treatment was successfully used for the removal of COD from 18000-25000 mg/L to below 200 mg/L from the ODB 2 production wastewater in a pilot experiment. A COD removal of 70%-80% was achieved by acidification-precipitation under a pH of 2.5-3.0. The first step biodegradafion permitted an average COD removal of 70% under an hydraulic residence time （HRT） of 30 h. By batch tests, the optimum conditions of Fenton＇s oxidation were acquired as： Fe^2＋ dose 6.0 mmol/L; H2O2 dose 3000 mg/L; and reaction time 6 h. The second step biological treatment could ensure an effluent COD below 200 mg/L under an HRT of 10 h following the Fenton＇s treatment.展开更多
以2-甲基咪唑和六水硝酸锌为前驱体制备金属有机骨架ZIF-8,将其溶于甲醇溶液中与硝酸银混合,将其煅烧制得Ag修饰的C掺杂ZnO材料(Ag/C-ZnO)。通过FTIR、XRD、SEM、DRS、XPS和BET等对材料进行结构、组成、形貌和孔径大小等分析。以甲基橙(...以2-甲基咪唑和六水硝酸锌为前驱体制备金属有机骨架ZIF-8,将其溶于甲醇溶液中与硝酸银混合,将其煅烧制得Ag修饰的C掺杂ZnO材料(Ag/C-ZnO)。通过FTIR、XRD、SEM、DRS、XPS和BET等对材料进行结构、组成、形貌和孔径大小等分析。以甲基橙(MO)溶液为降解模型,考察了催化剂的种类和催化剂的用量等因素。结果表明,Ag/C-ZnO催化剂稳定性好,催化活性强;在室温下0.030 g Ag/C-ZnO对50 mL c(MO)=10 mg/L溶液、降解60 min后的降解率为92.5%;且催化过程符合一级动力学模型。展开更多
The toxic organic dye contaminants in wastewater are extremely harmful to the ecosystem.Surface enhanced Raman scattering(SERS) is a technique with high sensitivity and chemical specificity which fulfills the requirem...The toxic organic dye contaminants in wastewater are extremely harmful to the ecosystem.Surface enhanced Raman scattering(SERS) is a technique with high sensitivity and chemical specificity which fulfills the requirements for monitoring dye contaminants in wastewater.However,as one of the common dye contaminants,methyl orange(MO) has very weak affinity to metallic surfaces and is difficult to be detected by SERS at low concentrations.Therefore,a new type of SERS substrate with Ag nanoparticle monolayer functionalized by mono-6-deoxy-6-thio-β-cyclodextrin(β-CD-SH) was prepared to efficiently capture and detect MO in wastewater with a limit of detection of 5×10^(-7) mol/L.The hydrophobic cavity of β-CD is responsible for the efficient trap and enrichment of MO on the Ag NPs surface,achieving a strong SERS signal of MO at low concentrations and at different pH values.This study provides new insight into designing a well-performed adsorbent for the capture and detection of organic contaminants.展开更多
文摘Magnetic Fe3O4 nanomagnetic particles were synthesized by the titration co-precipitation method followed by coating by the sol-gel method with Titamiun dioxide. The photocalytic activities of different synthesized TiO2/Fe304 nanomagnetic particles with different molar ratios of TiO2 to Fe3O4 were investigated by the reduction of phosphate, nitrate and decolorizing of methyl blue solutions. X-ray diffraction was used to characterize the size, composition and morphology of the synthesized particles. The results obtained from these experiments indicate an increase in the photocatalytic activity as the amount of TiO2 coating increases. The results show a higher activity of the synthesized particles in the removal of phosphate, nitrate and methyl blue, which can be achieved at early reaction periods at about 70-80%. The activities were higher when the particles were incubated without UV illumination. This study shows that TiO2/Fe3O4 particles are effective in phosphate, nitrate and methyl blue removal in wastewater treatment.
基金Supported by the National Science Foundation for Post Doctoral Scientists of China （20070411124）, Scientific and Technological Key Project of Shaanxi Province （2006k07-G19）, and Industrialization Project of Shaanxi Provincial Department of Education （06JC 11）.
文摘The adsorption of methyl orange onto ultrafine coal powder （UCP） and modified ultrafine coal powder （MUCP） from aqueous solutions were studied, in which the influence of contact time, dosage, temperature, pH, and methyl orange concentration in the solution were investigated. The adsorption kinetics of methyl orange by UCP and MUCP can be described by the Lagergren first-order and pseudo second-order kinetic models, respectively. The adsorption isotherms of methyl orange onto MUCP at 303, 313 and 323 K follow the Freundlich and Langmuir isotherm equation. Values of △G^0 for methyl orange adsorption onto MUCP are -22.55, -23.10 and -23.79 kJ·mol^-1 at 303, 313, and 323 K, respectively. The values of △H^0 and △S^0 are -3.74 kJ· mol^-1 and 61.99 J·mol^-1, respectively. The adsorption process is spontaneous and exothermic.
基金Project supported by the National Natural Science Foundation of China (No.50525824)Natural Science Fund of Xinjiang Province of China (No.200432109).
文摘High strength refractory organic stream is produced during the production of 2-phenylamino-3-methyl-6-di-n-butylaminofluoran （One Dye Black 2, abbr. ODB 2）, a novel heat-sensitive material with a promising market. In this study, a combination of acidificationprecipitation, primary biological treatment, Fenton＇s oxidation and another biological treatment was successfully used for the removal of COD from 18000-25000 mg/L to below 200 mg/L from the ODB 2 production wastewater in a pilot experiment. A COD removal of 70%-80% was achieved by acidification-precipitation under a pH of 2.5-3.0. The first step biodegradafion permitted an average COD removal of 70% under an hydraulic residence time （HRT） of 30 h. By batch tests, the optimum conditions of Fenton＇s oxidation were acquired as： Fe^2＋ dose 6.0 mmol/L; H2O2 dose 3000 mg/L; and reaction time 6 h. The second step biological treatment could ensure an effluent COD below 200 mg/L under an HRT of 10 h following the Fenton＇s treatment.
文摘以2-甲基咪唑和六水硝酸锌为前驱体制备金属有机骨架ZIF-8,将其溶于甲醇溶液中与硝酸银混合,将其煅烧制得Ag修饰的C掺杂ZnO材料(Ag/C-ZnO)。通过FTIR、XRD、SEM、DRS、XPS和BET等对材料进行结构、组成、形貌和孔径大小等分析。以甲基橙(MO)溶液为降解模型,考察了催化剂的种类和催化剂的用量等因素。结果表明,Ag/C-ZnO催化剂稳定性好,催化活性强;在室温下0.030 g Ag/C-ZnO对50 mL c(MO)=10 mg/L溶液、降解60 min后的降解率为92.5%;且催化过程符合一级动力学模型。
基金financial support from the National Natural Science Foundation of China(Nos.51601098,21775074 and 21861132016)the Natural Science Foundation of Tianjin(No.17JCQNJC05400)the National Key Research and Development Project of China(Nos.2017YFA0206702 and 2016YFB0901502)。
文摘The toxic organic dye contaminants in wastewater are extremely harmful to the ecosystem.Surface enhanced Raman scattering(SERS) is a technique with high sensitivity and chemical specificity which fulfills the requirements for monitoring dye contaminants in wastewater.However,as one of the common dye contaminants,methyl orange(MO) has very weak affinity to metallic surfaces and is difficult to be detected by SERS at low concentrations.Therefore,a new type of SERS substrate with Ag nanoparticle monolayer functionalized by mono-6-deoxy-6-thio-β-cyclodextrin(β-CD-SH) was prepared to efficiently capture and detect MO in wastewater with a limit of detection of 5×10^(-7) mol/L.The hydrophobic cavity of β-CD is responsible for the efficient trap and enrichment of MO on the Ag NPs surface,achieving a strong SERS signal of MO at low concentrations and at different pH values.This study provides new insight into designing a well-performed adsorbent for the capture and detection of organic contaminants.
