Ultrasonic field was applied in the treatment of oil emulsification wastewater by ZrO2 ceramic mem-brane. The permeate flux, rejection ratio in the filtration process and recovery ratio of flux in the membrane cleanin...Ultrasonic field was applied in the treatment of oil emulsification wastewater by ZrO2 ceramic mem-brane. The permeate flux, rejection ratio in the filtration process and recovery ratio of flux in the membrane cleaning process were measured. Great improvement in the permeate flux and rejection ratio have been observed for the membrane process enhanced by the ultrasonic field. The permeate flux of water through the membrane was about 210L.m^-2.h^-1 and the oil rejection ratio was over 99.9% under the optimal ultrasonic treatment conditions, which were 8W of ultrasonic power, 7cm of ultrasonic probe length introduced into the membrane channel and the same ultrasonic radiation direction as the wastewater flow. The resistance of the membrane process was compared between the cases with and without ultrasound, and the total resistance was reduced 68% by the use of ultrasound, Four methods including water cleaning, water cleaning under sonication, chemical cleaning and chemical cleaning under sonication were used to recover membrane flux. It was found that the flux recovery ratio increased with the increase of ultrasonic cleaning power. In addition, the use of chemical agents combining with ultrasonic irradiation showed a synergistic effect, which resulted in the highest cleaning efficiency and the shorter cleaning time.展开更多
In this paper, fouling mechanisms of mullite ceramic membranes for treatment of oily wastewaters in hybrid coagulation-microfiltration （MF） process presented. Hermia＇s models for cross flow filtration were used to ...In this paper, fouling mechanisms of mullite ceramic membranes for treatment of oily wastewaters in hybrid coagulation-microfiltration （MF） process presented. Hermia＇s models for cross flow filtration were used to investigate the fouling mechanisms of membranes with various coagulating chemicals concentrations. Four coagu lating chemicals （FeC12.4H20, FeSO4.7H20, A1C13-6H20 and A12（SO4）3.18H20） plus Ca（OH）2 of the same concen- tration were evaluated in the coagulation-MF hybrid process with different concentrations （0, 50 mg.L-1, 100 mg.L-1 and 200 mg.L-1）. To determine whether the data agree with models under consideration, the coefficients of determination （R2） of all models were compared with one another. In addition, average prediction errors of models were calculated. The results showed that cake filtration model can be applied for prediction of permeation flux decline for MF and coagulation-（MF） hybrid process with the best average error equal to 0.09%. Results indicated that pore blocking behavior changes as time of filtration increases, and one model cannot predict pore blocking behavior in all filtration time with very good precision.展开更多
The study presented the method for isolating the heterotrophic nitrifiers and the characterization of heterotrophic nitrification. When influent Ammonia nitrogen concentration was 42. 78 - 73. 62 mg/L. The average amm...The study presented the method for isolating the heterotrophic nitrifiers and the characterization of heterotrophic nitrification. When influent Ammonia nitrogen concentration was 42. 78 - 73. 62 mg/L. The average ammonia nitrogen removal rate was 81.32% from the bioceramics reactor. Sodium acetate and ammonium chloride were used as carbon and nitrogen source. The COD removal rates by microorganisms of strain wgy21 and wgy36 were 56.1% and 45.45%, respectively. The TN removal rates by microorganisms of strain wgy21 and wgy36 were 65.85% and 67. 98%, respectively. At the same time, the concentration of ammonium nitrogen was with the removal rates of 75.25% and 84.96%, and it also had the function of producing NO2 - N. Sodium acetate and sodium nitrite were used as carbon and nitrogen source. Through the 12 days of the aerobic culture, the COD femoral rates by microorganisms of strain wgy21 and wgy36 were 29.25% and 22.08%, respectively. NO2 -N concentration decreased slowly. Comparison, similarity of wgy21 and many Acinetobacter sp. ≥99%, similarity of wgy36 and many Acinetobacter sp. ≥99%. Refer to routine physiologicalbiochemical characteristic determination, further evidences showed that wgy21 and wgy36 belong to Acinetobacter sp., respectively.展开更多
基金Supported by the Special Funds for Major State Basic Research Program of China （973 Program, No.2003CB615707） and the National Natural Science Foundation of China （No.20436030）.
文摘Ultrasonic field was applied in the treatment of oil emulsification wastewater by ZrO2 ceramic mem-brane. The permeate flux, rejection ratio in the filtration process and recovery ratio of flux in the membrane cleaning process were measured. Great improvement in the permeate flux and rejection ratio have been observed for the membrane process enhanced by the ultrasonic field. The permeate flux of water through the membrane was about 210L.m^-2.h^-1 and the oil rejection ratio was over 99.9% under the optimal ultrasonic treatment conditions, which were 8W of ultrasonic power, 7cm of ultrasonic probe length introduced into the membrane channel and the same ultrasonic radiation direction as the wastewater flow. The resistance of the membrane process was compared between the cases with and without ultrasound, and the total resistance was reduced 68% by the use of ultrasound, Four methods including water cleaning, water cleaning under sonication, chemical cleaning and chemical cleaning under sonication were used to recover membrane flux. It was found that the flux recovery ratio increased with the increase of ultrasonic cleaning power. In addition, the use of chemical agents combining with ultrasonic irradiation showed a synergistic effect, which resulted in the highest cleaning efficiency and the shorter cleaning time.
文摘In this paper, fouling mechanisms of mullite ceramic membranes for treatment of oily wastewaters in hybrid coagulation-microfiltration （MF） process presented. Hermia＇s models for cross flow filtration were used to investigate the fouling mechanisms of membranes with various coagulating chemicals concentrations. Four coagu lating chemicals （FeC12.4H20, FeSO4.7H20, A1C13-6H20 and A12（SO4）3.18H20） plus Ca（OH）2 of the same concen- tration were evaluated in the coagulation-MF hybrid process with different concentrations （0, 50 mg.L-1, 100 mg.L-1 and 200 mg.L-1）. To determine whether the data agree with models under consideration, the coefficients of determination （R2） of all models were compared with one another. In addition, average prediction errors of models were calculated. The results showed that cake filtration model can be applied for prediction of permeation flux decline for MF and coagulation-（MF） hybrid process with the best average error equal to 0.09%. Results indicated that pore blocking behavior changes as time of filtration increases, and one model cannot predict pore blocking behavior in all filtration time with very good precision.
基金National Natural Science Foundation of China(NO.50521140075)
文摘The study presented the method for isolating the heterotrophic nitrifiers and the characterization of heterotrophic nitrification. When influent Ammonia nitrogen concentration was 42. 78 - 73. 62 mg/L. The average ammonia nitrogen removal rate was 81.32% from the bioceramics reactor. Sodium acetate and ammonium chloride were used as carbon and nitrogen source. The COD removal rates by microorganisms of strain wgy21 and wgy36 were 56.1% and 45.45%, respectively. The TN removal rates by microorganisms of strain wgy21 and wgy36 were 65.85% and 67. 98%, respectively. At the same time, the concentration of ammonium nitrogen was with the removal rates of 75.25% and 84.96%, and it also had the function of producing NO2 - N. Sodium acetate and sodium nitrite were used as carbon and nitrogen source. Through the 12 days of the aerobic culture, the COD femoral rates by microorganisms of strain wgy21 and wgy36 were 29.25% and 22.08%, respectively. NO2 -N concentration decreased slowly. Comparison, similarity of wgy21 and many Acinetobacter sp. ≥99%, similarity of wgy36 and many Acinetobacter sp. ≥99%. Refer to routine physiologicalbiochemical characteristic determination, further evidences showed that wgy21 and wgy36 belong to Acinetobacter sp., respectively.
