The effluent from the pulping of E. urophylla by alkali sodium sulfite chemi mechanical process(AS-CMP) was characterized for its biodegradability by photosynthetic bacteria (PSB). Chemical coagulation post treat...The effluent from the pulping of E. urophylla by alkali sodium sulfite chemi mechanical process(AS-CMP) was characterized for its biodegradability by photosynthetic bacteria (PSB). Chemical coagulation post treatment of biotreated wastewater was also studied. One month continuous treatment in the laboratory indicated that the COD Cr , BOD 5 and SS removals in biotreatment stages reached 56%, 83% and 89% respectively, and the CH 2Cl 2 extractives decreased from 10.7 mg/L to 7.7 mg/L. In chemical coagulation post treatment stage, the effects of process conditions, such as coagulant dosage, pH value and the coordinated coagulation flocculation treatment of three kinds of coagulants on coagulation effectiveness were discussed. The optimum operating conditions were given.展开更多
In order to study the feasibility of treating petro chemical wastewater by the combination of anaerobic and aerobic biological process, a research of treating wastewater in UASB reactor and aeration basin has been co...In order to study the feasibility of treating petro chemical wastewater by the combination of anaerobic and aerobic biological process, a research of treating wastewater in UASB reactor and aeration basin has been conducted. The test results shows that under moderate temperature, with 5\^2 kgCOD/(m\+3·d) volumetric load of COD Cr in the UASB reactor and 24h of HRT, 85% removal rate of BOD 5 and 83% of COD \{Cr\} and 1\^34 m\+3/(m\+3·d) volumetric gas production rate can be obtained respectively. The aerobic bio degradability can be increased by 20%—30% after the petro chemical wastewater has been treated by anaerobic process. As Ns=0\^45 kgCOD/(kgMLSS·d), HRT=4h in the aeration tank, 94% removal rate of BOD 5, 93% of COD \{Cr\}, 98\^8% total removal rate of COD \{Cr\} and 99% removal rate of BOD 5 can be reached.展开更多
Membrane fouling curtails severely the economical and practical implementation of membrane process. The fundamental principles and mechanisms of membrane fouling as well as factors affecting fouling have been summariz...Membrane fouling curtails severely the economical and practical implementation of membrane process. The fundamental principles and mechanisms of membrane fouling as well as factors affecting fouling have been summarized in this paper. It also has covered three fouling resistance models and four kinds of approaches to improve membrane performance. Membrane cleaning methods are also discussed including physical, chemical, physico\|chemical and biological methods. In the four groups of basic cleaning methods, biological cleaning has considerable advantages and potentials. Extensive research work should be carried out further to explore and develop new ideas and techniques in the field of membrane cleaning and restoration.展开更多
Polyferric\|silicate\|sulfate(PFSS),as a new type of coagulant,was prepared by using sodium silicate, sulfuric acid and ferric sulfate as materials.The zeta potential of hydrolyzate of PFSS under different pH values w...Polyferric\|silicate\|sulfate(PFSS),as a new type of coagulant,was prepared by using sodium silicate, sulfuric acid and ferric sulfate as materials.The zeta potential of hydrolyzate of PFSS under different pH values was investigated.The effects of Fe/SiO\-2 molar ratio and dosage of PFSS on turbidity removal were studied. The relation between the optimum coagulation pH range and Fe/SiO\-2 molar ratio was found and the coagulation mechanism of PFSS was discussed.The experimental results showed that Fe/SiO\-2 molar ratio has an effect on the zeta potential of hydrolyzate, the coagulation performance and the optimum coagulation pH range of PFSS and that PFSS gives the best turbidity removal effect when its Fe/SiO\-2 molar ratio was 1.5.展开更多
To demonstrate the feasibility of using bioaugmentation to enhance biodegradation of quinoline, four strains capable of using quinoline as sole source of carbon, nitrogen and energy were isolated from different enviro...To demonstrate the feasibility of using bioaugmentation to enhance biodegradation of quinoline, four strains capable of using quinoline as sole source of carbon, nitrogen and energy were isolated from different environmental samples by enrichment technique. Screening for quinoline degrader with the highest quinoline mineralizing rate was carried out in respirometer and one bacterium identified as \%Burkholderia pickettii W2\% was chosen as inoculum in bioaugmentation tests. Quinoline biodegradation experiment results showed that this bacterium degraded quinoline very quickly. 100, 200 and 500 mg/L quinoline can be transformed completely within 1, 2 and 7 hours respectively. A bioaugmentation procedure was proposed and laboratory experiments confirmed that bioaugmentation was an effective way to improve the performance of traditional wastewater treatment facilities for quinoline removal. The effect of inoculum size on bioaugmentation was also investigated in this paper.展开更多
The transfer kinetics of phenol between aqueous phase and N,N di(methyl heptyl) acetaminde (N503) in kerosene has been studied using Lewis cell technique. The effects of the factors including the concentrations of p...The transfer kinetics of phenol between aqueous phase and N,N di(methyl heptyl) acetaminde (N503) in kerosene has been studied using Lewis cell technique. The effects of the factors including the concentrations of phenol in aqueous phase and organic phase, the concentration of N503 in organic phase, the acidity of aqueous phase, the stirring speed and the temperature on the rates of forward and backward extraction of phenol have been examined. The regularity of extraction rate has been obtained. According to experimental results, the rates of both forward and backward extraction of phenol might be controlled by diffusion process. The diffusion step of phenol from aqueous phase to interface for forward extraction and from interface to aqueous phase for backward extraction might be the rate controlling steps.展开更多
The acidic wastewater containing manganese and other heavy metal ions came from the plant which produce titanium dioxide in the method of the sulfuric acid digestion was disposed under the processes of the pre\|neutra...The acidic wastewater containing manganese and other heavy metal ions came from the plant which produce titanium dioxide in the method of the sulfuric acid digestion was disposed under the processes of the pre\|neutralization with the mineral containing phosphorus and calcium, alkaline precipitation and re\|regulating pH with the raw wastewater. The removal ratio of manganese and ferrous were higher than 99% and 98%, respectively, when the concentration of manganese and ferrous were 46 mg/L and 2000 mg/L. More than 5800 mg/L of SO\+\{2-\}\-4 were neutralized also. The effluent pH was the range between 6 and 9, the concentration of other pollution substances were all very lower even have not discoveried.展开更多
Azo dye cationic blue X GRL, which is non biodegradable toxic organic compound, is decolorized and subsequently mineralized by UV/H 2O 2/N 2 or UV/H 2O 2/air (O 2) system. The effects of initial solution conce...Azo dye cationic blue X GRL, which is non biodegradable toxic organic compound, is decolorized and subsequently mineralized by UV/H 2O 2/N 2 or UV/H 2O 2/air (O 2) system. The effects of initial solution concentration, initial solution pH, and some ions produced during the degradation on the rate of decolorization of cationic blue X GRL were investigated. The photodegradation of cationic blue X GRL approximately follows first order kinetics. The regression curve of the natural logarithm of concentration verus reaction time becomes less linear with initial concentration increasing. Oxygen and appropriate OH\+· generator can accelerate reaction rate. The effect of reaction atmosphere, initial concentration, light intensity on the optimal dosage of H 2O 2 were studied. It was found that the optimal H 2O 2 dosage was determined by UV light intensity. These intermediates of cationic blue X GRL decolorization are biodegradable.展开更多
On the basis of fractal theory, the fractal characteristics of filamentous bacteria in activated sludge are studied by image dissector system. The results show that the spatial distribution structure of filamentous ...On the basis of fractal theory, the fractal characteristics of filamentous bacteria in activated sludge are studied by image dissector system. The results show that the spatial distribution structure of filamentous bacteria in activated sludge has high self similarity in statistics and the filamentous bacteria have clear phenomenon of fractal growth. The critical fractal dimension values of filamentous bacteria bulking such as Eikelboom 021N, Eikelboom 1701, Sphaerotilus natans and Eikelboom 0041 are determined initially. The fractal dimensions can be taken as a parameter to describe filamentous bacteria of activated sludge quantitatively and bring to light the disorder in appearance and the rule in inherence of filamentous bacteria system.展开更多
The novel ways for the filtration improvement of zinc hydroxide sludge precipitated from the zinc\|containing solutions was investigated. It was found that, when the zinc\|containing solutions were added to sodium hyd...The novel ways for the filtration improvement of zinc hydroxide sludge precipitated from the zinc\|containing solutions was investigated. It was found that, when the zinc\|containing solutions were added to sodium hydroxide solution, the filtration of the obtained precipitates was improved to some extent, depending on the molar ratios of OH\+-/Zn, in comparison with those obtained by conventional addition of hydroxide solution to zinc\|containing solution, even the ratios were kept the same in these two alkalization methods. The experimental results showed that such an improvement may be contributed to the presence of muddy precipitates formed homogeneously in the sludge. It was suggested that it was zinc\|containing solution that should be added into hydroxide solution, when the zinc was removed from aqueous solution by the precipitation of zinc hydroxides. As a result, the sludge obtained will be filtered and rinsed readily.展开更多
文摘The effluent from the pulping of E. urophylla by alkali sodium sulfite chemi mechanical process(AS-CMP) was characterized for its biodegradability by photosynthetic bacteria (PSB). Chemical coagulation post treatment of biotreated wastewater was also studied. One month continuous treatment in the laboratory indicated that the COD Cr , BOD 5 and SS removals in biotreatment stages reached 56%, 83% and 89% respectively, and the CH 2Cl 2 extractives decreased from 10.7 mg/L to 7.7 mg/L. In chemical coagulation post treatment stage, the effects of process conditions, such as coagulant dosage, pH value and the coordinated coagulation flocculation treatment of three kinds of coagulants on coagulation effectiveness were discussed. The optimum operating conditions were given.
文摘In order to study the feasibility of treating petro chemical wastewater by the combination of anaerobic and aerobic biological process, a research of treating wastewater in UASB reactor and aeration basin has been conducted. The test results shows that under moderate temperature, with 5\^2 kgCOD/(m\+3·d) volumetric load of COD Cr in the UASB reactor and 24h of HRT, 85% removal rate of BOD 5 and 83% of COD \{Cr\} and 1\^34 m\+3/(m\+3·d) volumetric gas production rate can be obtained respectively. The aerobic bio degradability can be increased by 20%—30% after the petro chemical wastewater has been treated by anaerobic process. As Ns=0\^45 kgCOD/(kgMLSS·d), HRT=4h in the aeration tank, 94% removal rate of BOD 5, 93% of COD \{Cr\}, 98\^8% total removal rate of COD \{Cr\} and 99% removal rate of BOD 5 can be reached.
文摘Membrane fouling curtails severely the economical and practical implementation of membrane process. The fundamental principles and mechanisms of membrane fouling as well as factors affecting fouling have been summarized in this paper. It also has covered three fouling resistance models and four kinds of approaches to improve membrane performance. Membrane cleaning methods are also discussed including physical, chemical, physico\|chemical and biological methods. In the four groups of basic cleaning methods, biological cleaning has considerable advantages and potentials. Extensive research work should be carried out further to explore and develop new ideas and techniques in the field of membrane cleaning and restoration.
文摘Polyferric\|silicate\|sulfate(PFSS),as a new type of coagulant,was prepared by using sodium silicate, sulfuric acid and ferric sulfate as materials.The zeta potential of hydrolyzate of PFSS under different pH values was investigated.The effects of Fe/SiO\-2 molar ratio and dosage of PFSS on turbidity removal were studied. The relation between the optimum coagulation pH range and Fe/SiO\-2 molar ratio was found and the coagulation mechanism of PFSS was discussed.The experimental results showed that Fe/SiO\-2 molar ratio has an effect on the zeta potential of hydrolyzate, the coagulation performance and the optimum coagulation pH range of PFSS and that PFSS gives the best turbidity removal effect when its Fe/SiO\-2 molar ratio was 1.5.
文摘To demonstrate the feasibility of using bioaugmentation to enhance biodegradation of quinoline, four strains capable of using quinoline as sole source of carbon, nitrogen and energy were isolated from different environmental samples by enrichment technique. Screening for quinoline degrader with the highest quinoline mineralizing rate was carried out in respirometer and one bacterium identified as \%Burkholderia pickettii W2\% was chosen as inoculum in bioaugmentation tests. Quinoline biodegradation experiment results showed that this bacterium degraded quinoline very quickly. 100, 200 and 500 mg/L quinoline can be transformed completely within 1, 2 and 7 hours respectively. A bioaugmentation procedure was proposed and laboratory experiments confirmed that bioaugmentation was an effective way to improve the performance of traditional wastewater treatment facilities for quinoline removal. The effect of inoculum size on bioaugmentation was also investigated in this paper.
文摘The transfer kinetics of phenol between aqueous phase and N,N di(methyl heptyl) acetaminde (N503) in kerosene has been studied using Lewis cell technique. The effects of the factors including the concentrations of phenol in aqueous phase and organic phase, the concentration of N503 in organic phase, the acidity of aqueous phase, the stirring speed and the temperature on the rates of forward and backward extraction of phenol have been examined. The regularity of extraction rate has been obtained. According to experimental results, the rates of both forward and backward extraction of phenol might be controlled by diffusion process. The diffusion step of phenol from aqueous phase to interface for forward extraction and from interface to aqueous phase for backward extraction might be the rate controlling steps.
文摘The acidic wastewater containing manganese and other heavy metal ions came from the plant which produce titanium dioxide in the method of the sulfuric acid digestion was disposed under the processes of the pre\|neutralization with the mineral containing phosphorus and calcium, alkaline precipitation and re\|regulating pH with the raw wastewater. The removal ratio of manganese and ferrous were higher than 99% and 98%, respectively, when the concentration of manganese and ferrous were 46 mg/L and 2000 mg/L. More than 5800 mg/L of SO\+\{2-\}\-4 were neutralized also. The effluent pH was the range between 6 and 9, the concentration of other pollution substances were all very lower even have not discoveried.
文摘Azo dye cationic blue X GRL, which is non biodegradable toxic organic compound, is decolorized and subsequently mineralized by UV/H 2O 2/N 2 or UV/H 2O 2/air (O 2) system. The effects of initial solution concentration, initial solution pH, and some ions produced during the degradation on the rate of decolorization of cationic blue X GRL were investigated. The photodegradation of cationic blue X GRL approximately follows first order kinetics. The regression curve of the natural logarithm of concentration verus reaction time becomes less linear with initial concentration increasing. Oxygen and appropriate OH\+· generator can accelerate reaction rate. The effect of reaction atmosphere, initial concentration, light intensity on the optimal dosage of H 2O 2 were studied. It was found that the optimal H 2O 2 dosage was determined by UV light intensity. These intermediates of cationic blue X GRL decolorization are biodegradable.
文摘On the basis of fractal theory, the fractal characteristics of filamentous bacteria in activated sludge are studied by image dissector system. The results show that the spatial distribution structure of filamentous bacteria in activated sludge has high self similarity in statistics and the filamentous bacteria have clear phenomenon of fractal growth. The critical fractal dimension values of filamentous bacteria bulking such as Eikelboom 021N, Eikelboom 1701, Sphaerotilus natans and Eikelboom 0041 are determined initially. The fractal dimensions can be taken as a parameter to describe filamentous bacteria of activated sludge quantitatively and bring to light the disorder in appearance and the rule in inherence of filamentous bacteria system.
文摘The novel ways for the filtration improvement of zinc hydroxide sludge precipitated from the zinc\|containing solutions was investigated. It was found that, when the zinc\|containing solutions were added to sodium hydroxide solution, the filtration of the obtained precipitates was improved to some extent, depending on the molar ratios of OH\+-/Zn, in comparison with those obtained by conventional addition of hydroxide solution to zinc\|containing solution, even the ratios were kept the same in these two alkalization methods. The experimental results showed that such an improvement may be contributed to the presence of muddy precipitates formed homogeneously in the sludge. It was suggested that it was zinc\|containing solution that should be added into hydroxide solution, when the zinc was removed from aqueous solution by the precipitation of zinc hydroxides. As a result, the sludge obtained will be filtered and rinsed readily.
