A pilot scale(10 m 3/d) anoxic/oxic membrane bioreactor(A/O MBR) was tested for dyeing wastewater treatment of woolen mill without wasting sludge in 125 days operation. Results showed that the effluent quality was exc...A pilot scale(10 m 3/d) anoxic/oxic membrane bioreactor(A/O MBR) was tested for dyeing wastewater treatment of woolen mill without wasting sludge in 125 days operation. Results showed that the effluent quality was excellent, i.e. effluent COD less than 25 mg/L, BOD 5 under 5 mg/L, turbidity lower than 0 65 NTU, and colour less than 30 DT, and met with the reuse water standard of China. The removal rates of COD, BOD 5, colour, and turbidity were 92 4%, 98 4%, 74% and 98 9%, respectively. Constant flux operation mode was carried out in this study, and backwash was effective for reducing membrane fouling and maintaining constant flux. Membrane fouling had heavy impact on energy consumption. More attention should be paid on pipe selection and design for the sidestream MBR system, too.展开更多
Many different techniques may be used to remove industrial pollutants from wastewater. Adsorption using activated carbon has been reported to be an effective method. This work proposes the use of a vegetable residue(b...Many different techniques may be used to remove industrial pollutants from wastewater. Adsorption using activated carbon has been reported to be an effective method. This work proposes the use of a vegetable residue(black sapote seeds) as a raw material for its synthesis. These carbons were chemically activated using phosphoric acid and carbonized at 673 and 873 K. Adsorption isotherms were constructed for the textile dyes on the carbons, and this data was treated using Langmuir’s equation to quantitatively describe the adsorption process. The synthesized carbons were characterized using FTIR, EA, SEM, Nitrogen adsorption(specific surface areas of 879 and 652 m2·g-1), and their points of zero charge(2.1 and 2.3). It was possible to adsorb both heavy metals and textile dyes present in aqueous solutions and wastewaters using these activated carbons. Heavy metals were adsorbed almost completely by both carbons. Cationic dyes where adsorbed(58–59.8 mg·g-1) in greater amounts compared to anionic dyes(10–58.8 mg·g-1). The amount of anionic dyes adsorbed increased almost 30% by changing the pH of the solutions. One of the carbons was thermally regenerated on three occasions without losing its adsorption capacity and it was proved in a flow system.展开更多
Nowadays, wastewater from dyeing industries became a challenging issue in the world. Researchers have reported several techniques to treat those effluents based on their projects. Adsorption is the most common method ...Nowadays, wastewater from dyeing industries became a challenging issue in the world. Researchers have reported several techniques to treat those effluents based on their projects. Adsorption is the most common method because of cheap, simple and effective method. In this work, activated carbon was used for dye adsorption purpose. This adsorbent has high surface area and high porosity to remove dye. This review highlighted some important results of the last few years regarding the use of activated carbon in wastewater treatment. Research findings supported that adsorption process is spontaneous in nature. Adsorption data confirmed Langmuir model, indicating the chemisorption occurred.展开更多
Fe-doped TiO 2 coated on activated carbon （Fe-TiO 2 /AC, FTA） composites were prepared by an improved sol-gel method and characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffrac...Fe-doped TiO 2 coated on activated carbon （Fe-TiO 2 /AC, FTA） composites were prepared by an improved sol-gel method and characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffractometry, inductively coupled plasma mass spectrometry and BET surface area analysis. Obtained FTA composites were applied to the continuous treatment of dye wastewater in a dynamic reactor. The effects of Fe ion content, catalyst content, UV-lamp power and flowrate of the continuous treatment of dye wastewater on degradation efficiency were analyzed to determine the optimum operating conditions of dye wastewater degradation. Continuous photocatalytic experiments provided interesting results that FTA had a high chemical oxygen demand （COD） removal rate compared with TiO 2 , Fe doped TiO 2 （FT） and TiO 2 coated on activated carbon （TA）. In particular, when using the FTA catalyst with a Fe ion content of 0.33%, the kinetic content （k = 0.0376） of COD removal was more than the sum of both TA （0.0205） and 0.33% FT （0.0166）. FTA showed a high photoactivity because of a synergistic effect between Fe ions and AC on TiO 2 , which is higher than the individual effects of AC or Fe ions on TiO 2 . Additionally, for the photocatalytic degradation of dye wastewater, the optimum Fe ion content, catalyst content, UV-lamp power and flowrate were 0.33%, 6 g/L, 60 W （two lamps） and 300 mL/hr, respectively. An investigation of catalyst reuse revealed that the 0.33% FTA showed almost no deactivation in photocatalytic degradation of naturally treated wastewater.展开更多
文摘A pilot scale(10 m 3/d) anoxic/oxic membrane bioreactor(A/O MBR) was tested for dyeing wastewater treatment of woolen mill without wasting sludge in 125 days operation. Results showed that the effluent quality was excellent, i.e. effluent COD less than 25 mg/L, BOD 5 under 5 mg/L, turbidity lower than 0 65 NTU, and colour less than 30 DT, and met with the reuse water standard of China. The removal rates of COD, BOD 5, colour, and turbidity were 92 4%, 98 4%, 74% and 98 9%, respectively. Constant flux operation mode was carried out in this study, and backwash was effective for reducing membrane fouling and maintaining constant flux. Membrane fouling had heavy impact on energy consumption. More attention should be paid on pipe selection and design for the sidestream MBR system, too.
基金VIEP-BUAP,Mexico for their financial support during the development of the project PECA-ING-17-GCONACYT,Mexico for scholarship number 596493.
文摘Many different techniques may be used to remove industrial pollutants from wastewater. Adsorption using activated carbon has been reported to be an effective method. This work proposes the use of a vegetable residue(black sapote seeds) as a raw material for its synthesis. These carbons were chemically activated using phosphoric acid and carbonized at 673 and 873 K. Adsorption isotherms were constructed for the textile dyes on the carbons, and this data was treated using Langmuir’s equation to quantitatively describe the adsorption process. The synthesized carbons were characterized using FTIR, EA, SEM, Nitrogen adsorption(specific surface areas of 879 and 652 m2·g-1), and their points of zero charge(2.1 and 2.3). It was possible to adsorb both heavy metals and textile dyes present in aqueous solutions and wastewaters using these activated carbons. Heavy metals were adsorbed almost completely by both carbons. Cationic dyes where adsorbed(58–59.8 mg·g-1) in greater amounts compared to anionic dyes(10–58.8 mg·g-1). The amount of anionic dyes adsorbed increased almost 30% by changing the pH of the solutions. One of the carbons was thermally regenerated on three occasions without losing its adsorption capacity and it was proved in a flow system.
文摘Nowadays, wastewater from dyeing industries became a challenging issue in the world. Researchers have reported several techniques to treat those effluents based on their projects. Adsorption is the most common method because of cheap, simple and effective method. In this work, activated carbon was used for dye adsorption purpose. This adsorbent has high surface area and high porosity to remove dye. This review highlighted some important results of the last few years regarding the use of activated carbon in wastewater treatment. Research findings supported that adsorption process is spontaneous in nature. Adsorption data confirmed Langmuir model, indicating the chemisorption occurred.
基金supported by the National Natural Science Foundation of China (No. 50802034)the Educationaland Technological Department of Hunan Province (No.08B063)the Natural Science Foundation of Hunan Province (No. 09JJ6101)
文摘Fe-doped TiO 2 coated on activated carbon （Fe-TiO 2 /AC, FTA） composites were prepared by an improved sol-gel method and characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffractometry, inductively coupled plasma mass spectrometry and BET surface area analysis. Obtained FTA composites were applied to the continuous treatment of dye wastewater in a dynamic reactor. The effects of Fe ion content, catalyst content, UV-lamp power and flowrate of the continuous treatment of dye wastewater on degradation efficiency were analyzed to determine the optimum operating conditions of dye wastewater degradation. Continuous photocatalytic experiments provided interesting results that FTA had a high chemical oxygen demand （COD） removal rate compared with TiO 2 , Fe doped TiO 2 （FT） and TiO 2 coated on activated carbon （TA）. In particular, when using the FTA catalyst with a Fe ion content of 0.33%, the kinetic content （k = 0.0376） of COD removal was more than the sum of both TA （0.0205） and 0.33% FT （0.0166）. FTA showed a high photoactivity because of a synergistic effect between Fe ions and AC on TiO 2 , which is higher than the individual effects of AC or Fe ions on TiO 2 . Additionally, for the photocatalytic degradation of dye wastewater, the optimum Fe ion content, catalyst content, UV-lamp power and flowrate were 0.33%, 6 g/L, 60 W （two lamps） and 300 mL/hr, respectively. An investigation of catalyst reuse revealed that the 0.33% FTA showed almost no deactivation in photocatalytic degradation of naturally treated wastewater.
