The aerobic granular sludge was cultivated in a pilot-scale sequencing batch reactor （SBR）, and some of the granules were stored at 8 ℃ for 150 d. Extracellular polymeric substances （EPS） of sludge samples were e...The aerobic granular sludge was cultivated in a pilot-scale sequencing batch reactor （SBR）, and some of the granules were stored at 8 ℃ for 150 d. Extracellular polymeric substances （EPS） of sludge samples were extracted and analyzed during the granulation and storage process. The results show that the contents of protein and EPS increase along with the granulation process, while polysaccharides remain almost unchanged. The content of protein in EPS is almost two-fold larger than that of polysaccharides in granular sludge cultivated with municipal wastewater. Moreover, some of the granules disintegrate during storage, corresponding to the decrease of protein contents in EPS. Three peaks are identified in three-dimensional excitation emission matrix （EEM） fluorescence spectra of the EPS in the aerobic granules. Two peaks （A and B） are attributed to the protein-like fluorophores, and the third （peak C） is related to visible fulvic-like substances. Peak A gradually disappears during storage, while a new peak related to ultraviolet fulvic acid （peak D） is formed. The formation and the stability of aerobic granules are closely dependent on the quantity and composition of EPS proteins. Peak C has no obvious changes during granulation, while the fulvic-like substances present an increase in fluorescence intensities during storage, accompanied with an increase in structural complexity. The fulvie-like substances are also associated with the disintegration of the aerobic granules.展开更多
In order to enhance the efficiency of aerobic digestion, the excess sludge was irradiated by low intensity ultrasound at a frequency of 28 kHz and acoustic intensity of 0.53 W/cm^2. The results show that the sludge st...In order to enhance the efficiency of aerobic digestion, the excess sludge was irradiated by low intensity ultrasound at a frequency of 28 kHz and acoustic intensity of 0.53 W/cm^2. The results show that the sludge stabilization without ultrasonic treatment can be achieved after 17 d of digestion, whereas the digestion time of ultrasonic groups can be cut by 3-7 d. During the same digestion elapsing, in ultrasonic groups the total volatile suspended solid removal rate is higher than that in the control group. The kinetics of aerobic digestion of excess sludge with ultrasound can also be described with first-order reaction.展开更多
Static aerobic composting of municipal sewage sludge with forced ventilation or air ventilation using matured compost as bulking conditioner was investigated. Physical and chemical parame ,eters, e.g., temperature, mo...Static aerobic composting of municipal sewage sludge with forced ventilation or air ventilation using matured compost as bulking conditioner was investigated. Physical and chemical parame ,eters, e.g., temperature, moisture content, VSS, CODcr, pH, and germination index （GI）, were analyzed to characterize the composting process. Fermentation starts quickly in both forced and air ventilation compost heaps and reaches high-temperature stage after 2 d, owing to the bulking function of matured compost. Compared to air ventilation, however, forced ventilation enables the high-temperature stage to last longer for approximately 7 d. The moisture content of both compost bodies decreases from 62% to about 50% as a result of evaporation, and it decreases slightly faster in forced ventilation compost heap after 13 d due to the higher temperature and better ventilation condition. Although no obvious differences of VSS and pH are observed between both compost heaps, the soluble CODcr and GI show differences during the second half period of fermentation. In forced ventilation compost, the soluble CODcr has a small rebound after 13 d, and GI decreases from 46% to 35% but then increases. These results show that in general, the matured compost is a good conditioner and force ventilation with a proper air supply strategy can be more efficient than air ventilation.展开更多
The research was aimed at studying the effect of adding certain proportion chicken manure to cattle manure on compost below 0℃ with aerobic compost method, which was suitable for northern cold climate. The results in...The research was aimed at studying the effect of adding certain proportion chicken manure to cattle manure on compost below 0℃ with aerobic compost method, which was suitable for northern cold climate. The results indicated that the mixed compost completed 3 days earlier than the single compost, the temperature of the mixed compost rose to 50.7℃ at the 1st day,and achieved its highest temperature 74.4℃ at the 3rd day. The temperature of the single compost rose to 40.0℃ at the 1st day,rose to 55.6℃ at the 3rd day,and achieved its highest temperature 70.1℃ at the 5th day. Adding chicken manure had no impact on the variety trend of the process parameters such as moisture content, pH and C/N ratio, hut increased the variety range of these parameters.展开更多
Three strains of aerobic denitrifiers,named as AT3,AT6 and AT7,were isolated from concentric-circles reactor with diversion wall possessing simultaneous nitrification and denitrification (SND) effect of 69%. The three...Three strains of aerobic denitrifiers,named as AT3,AT6 and AT7,were isolated from concentric-circles reactor with diversion wall possessing simultaneous nitrification and denitrification (SND) effect of 69%. The three strains are all gram-positive and rod-shaped,and their colonial colors are pale yellow,milk white and pink,respectively. Combined with 16SrDNA sequence homology comparison and biochemical tests,AT3 and AT7 were identified to belong to Rhodococcus,and AT6 to Gordonia. These bacterial strains could grow well in the medium with potassium nitrate as nitrogen source and sodium citrate as carbon source. Based on the enhanced nitrogen removal experiments of selected bacteria mixture for activated sludge,the inoculum amount of 5% was supposed to be proper. The mixed biomass suspension of selected strains with PVA immobilization was put into the concentric-circles reactor in order to study the characteristics of enhanced nitrogen removal after amplifying cultivation with inoculated amount of 5%. The experimental results show that the average removal efficiencies of ammonia nitrogen (NH3-N) and total nitrogen (TN) in the reactor enhanced with aerobic denitrifying bacteria using PVA are 92.18% and 79.14% respectively,increasing by 5.29% and 7.83% respectively compared with removal effects of control group without strains enhancement.展开更多
A bacterium strain HS-03 was isolated from the activated sludge plant in a suburb of Wuhan city,China which has been found to be capable of aerobic denitrification.The effect of different inoculated amounts of pre-cul...A bacterium strain HS-03 was isolated from the activated sludge plant in a suburb of Wuhan city,China which has been found to be capable of aerobic denitrification.The effect of different inoculated amounts of pre-cultured media was analyzed.The denitrifying rates of this strain under aerobic and micro-anaerobic conditions were compared.The result indicated that the rate was almost not affected by the presence of oxygen.10m M nitrate was removed more than 90%in 36 hours by this bacterium in the specific medium.During the denitrifying process,nitrite was always kept at very low level.The denitrification potential of this bacterium was evaluated to treat artificial wastewater under fully aerobic conditions.Main biochemical and physiological features of this strain were characterized.The 16S rDNA sequence was compared with the published data in GenBank by using BLAST.The BLAST level of similarity to Pseudomonas stutzeri was 99.1%.These results of phenotype and genotype proved that the strain HS-03 was a new strain belonging to the species of P.stutzeri.展开更多
2,4,6-trinitrotoluene(TNT) and its derivatives are nitrogen-containing aromatic compounds having chemical and thermal stability at ambient temperature and pressure. TNT has high toxicity and mutagenic activity to huma...2,4,6-trinitrotoluene(TNT) and its derivatives are nitrogen-containing aromatic compounds having chemical and thermal stability at ambient temperature and pressure. TNT has high toxicity and mutagenic activity to humans, plants and animals, thus decontamination processes are necessary. Many microorganisms are capable to bioremediate TNT such as bacteria from the genera Pseudomonas,Enterobacter, Rhodococcus, Mycobacterium, Clostridium and Desulfovibrio: fungus such as Phanerochate and Stropharia species are able to perform TNT biotransformation under aerobic and anaerobic conditions. In this work we review the state of TNT biodegradation by various routes: aerobic, anaerobic,combined, fungal, enzymatic, and bio-electrochemical.展开更多
A full-scale experimental study of treating mustard wastewater by the integrated bioreactor with designed scale of 1 000 m3/d is conducted combined with a demonstration project. The systematical researches on the effi...A full-scale experimental study of treating mustard wastewater by the integrated bioreactor with designed scale of 1 000 m3/d is conducted combined with a demonstration project. The systematical researches on the efficiency of combined operation conditions of anaerobic-aerobic and anaerobic-aerobic-flocculation as well as chemical phosphorus removal of hypersaline mustard wastewater are conducted. The optimal operation condition and parameters in pretreatment of mustard wastewater in winter （the water temperature ranges 8-15 ~C） are determined： the anaerobic load is 3.0 kg （COD）/（m3.d）, the average COD and phosphate concentration of the inflow are respectively 3 883 mg/L and 35.53 mg/L and the dosage of flocculent （PAC） is 400 mg/L. The anaerobic-aerobic-flocculation combined operation condition and postpositive phosphorous removal with ferrous sulfate are employed. After treatment, the COD of the effluent is 470 mg/L and the average phosphate concentration is 5.09 mg/L. The effluent could achieve the third-level of Integrated Wastewater Discharge Standard （GB 8978--1996）.展开更多
Molecular iodine was first utilized for direct oxidation of a-isophorone （α-IP） to ketoisophorone （KIP） with molecule oxygen at room temperature and the effects of amount of iodine, solvents and reaction time wer...Molecular iodine was first utilized for direct oxidation of a-isophorone （α-IP） to ketoisophorone （KIP） with molecule oxygen at room temperature and the effects of amount of iodine, solvents and reaction time were investigated extensively. The optimized result shows that 70.2% conversion of a-isophorone and 82.6% selectivity of ketoisophorone are obtained with 15% iodine （molar fraction） in acetonitrile under photoirradiation for 5 h. Moreover, the possible mechanism is proposed.展开更多
Laboratory experiments were conducted to investigate the transformation and performance of a granular sequence batch reactor(SBR) under the conventional organic loading rate(OLR) condition.Aerobic granules were succes...Laboratory experiments were conducted to investigate the transformation and performance of a granular sequence batch reactor(SBR) under the conventional organic loading rate(OLR) condition.Aerobic granules were successfully cultivated in a SBR by means of alternative feeding load combined with reducing settling time after 60 d operational period.Subsequently,the black fungal granules were presented in reactor because of the filamentous overgrowth on the surface of aerobic granules.A small amount of fungal granules had no effect on the performance of granular SBR.Aerobic granules completely vanished and fungal granules eventually became the dominant species in subsequent 90 d operation after granulation.The three-dimensional excitation emission matrix(EEM) spectra result shows that the extracellular polymeric substances(EPS) component in both granules has no much difference,whereas the content of EPS in fungal granules is higher than that in bacterial granules.Due to their low bioactivity,the chemical oxidation demand(COD) and NH4-N removal efficiencies gradually decrease from 90.4%–96.5% and 99.5% to 71.8% and 32.9% respectively while the fungal granules become dominant in the SBR.展开更多
The amino acid Schiff base complex (Sal-AMBA-Mn) was prepared with p-amino-methylbenzoic acid, salicylaldehyde and Mn(OAc)2·4H2O. Its structures was characterized with IR and UV spectra. Oxygenation mechanism of ...The amino acid Schiff base complex (Sal-AMBA-Mn) was prepared with p-amino-methylbenzoic acid, salicylaldehyde and Mn(OAc)2·4H2O. Its structures was characterized with IR and UV spectra. Oxygenation mechanism of the complex in N, N-dimethylformamide solution was investigated. The results show that lower temperature is in favor of the oxygenation, and energy, enthalpy and entropy are -3.8 kJ/mol, -4.2 J/mol and -161.44 J/(mol·K), respectively. In the presence of the manganese complex, dehydroepiandrosterone acetate is effectively oxidized by molecular oxygen and the corresponding enone 7-ketodehydroepiandrosterone acetate is obtained. The yield is 62.1% when the oxidation is carried out under the reaction conditions of 60 ℃, 2 MPa of O2 pressure, C5H5N as a solvent and molar ratio of the substrate to the complex of 1:10.展开更多
基金Project(2006AA06Z318) supported by the National High-Tech Research and Development Program of China
文摘The aerobic granular sludge was cultivated in a pilot-scale sequencing batch reactor （SBR）, and some of the granules were stored at 8 ℃ for 150 d. Extracellular polymeric substances （EPS） of sludge samples were extracted and analyzed during the granulation and storage process. The results show that the contents of protein and EPS increase along with the granulation process, while polysaccharides remain almost unchanged. The content of protein in EPS is almost two-fold larger than that of polysaccharides in granular sludge cultivated with municipal wastewater. Moreover, some of the granules disintegrate during storage, corresponding to the decrease of protein contents in EPS. Three peaks are identified in three-dimensional excitation emission matrix （EEM） fluorescence spectra of the EPS in the aerobic granules. Two peaks （A and B） are attributed to the protein-like fluorophores, and the third （peak C） is related to visible fulvic-like substances. Peak A gradually disappears during storage, while a new peak related to ultraviolet fulvic acid （peak D） is formed. The formation and the stability of aerobic granules are closely dependent on the quantity and composition of EPS proteins. Peak C has no obvious changes during granulation, while the fulvic-like substances present an increase in fluorescence intensities during storage, accompanied with an increase in structural complexity. The fulvie-like substances are also associated with the disintegration of the aerobic granules.
文摘In order to enhance the efficiency of aerobic digestion, the excess sludge was irradiated by low intensity ultrasound at a frequency of 28 kHz and acoustic intensity of 0.53 W/cm^2. The results show that the sludge stabilization without ultrasonic treatment can be achieved after 17 d of digestion, whereas the digestion time of ultrasonic groups can be cut by 3-7 d. During the same digestion elapsing, in ultrasonic groups the total volatile suspended solid removal rate is higher than that in the control group. The kinetics of aerobic digestion of excess sludge with ultrasound can also be described with first-order reaction.
基金Projects(50978087,50908081)supported by the National Natural Science Foundation of China
文摘Static aerobic composting of municipal sewage sludge with forced ventilation or air ventilation using matured compost as bulking conditioner was investigated. Physical and chemical parame ,eters, e.g., temperature, moisture content, VSS, CODcr, pH, and germination index （GI）, were analyzed to characterize the composting process. Fermentation starts quickly in both forced and air ventilation compost heaps and reaches high-temperature stage after 2 d, owing to the bulking function of matured compost. Compared to air ventilation, however, forced ventilation enables the high-temperature stage to last longer for approximately 7 d. The moisture content of both compost bodies decreases from 62% to about 50% as a result of evaporation, and it decreases slightly faster in forced ventilation compost heap after 13 d due to the higher temperature and better ventilation condition. Although no obvious differences of VSS and pH are observed between both compost heaps, the soluble CODcr and GI show differences during the second half period of fermentation. In forced ventilation compost, the soluble CODcr has a small rebound after 13 d, and GI decreases from 46% to 35% but then increases. These results show that in general, the matured compost is a good conditioner and force ventilation with a proper air supply strategy can be more efficient than air ventilation.
基金Supported by Prevent and Cure the Livestock and Poultry Industry Pollution Fund of Exchequer Department National Environmental Protection Department (2004)
文摘The research was aimed at studying the effect of adding certain proportion chicken manure to cattle manure on compost below 0℃ with aerobic compost method, which was suitable for northern cold climate. The results indicated that the mixed compost completed 3 days earlier than the single compost, the temperature of the mixed compost rose to 50.7℃ at the 1st day,and achieved its highest temperature 74.4℃ at the 3rd day. The temperature of the single compost rose to 40.0℃ at the 1st day,rose to 55.6℃ at the 3rd day,and achieved its highest temperature 70.1℃ at the 5th day. Adding chicken manure had no impact on the variety trend of the process parameters such as moisture content, pH and C/N ratio, hut increased the variety range of these parameters.
基金Science and Technology Cooperation Project (2007DFA90660) supported by the International Cooperation Program of Ministry of Science and TechnologyProject(CSTC,2008BB7305) supported by the Natural Science Funds of ChongqingProject(CSTS,2006AA7003) supported by the Major Scientific and Technical Program
文摘Three strains of aerobic denitrifiers,named as AT3,AT6 and AT7,were isolated from concentric-circles reactor with diversion wall possessing simultaneous nitrification and denitrification (SND) effect of 69%. The three strains are all gram-positive and rod-shaped,and their colonial colors are pale yellow,milk white and pink,respectively. Combined with 16SrDNA sequence homology comparison and biochemical tests,AT3 and AT7 were identified to belong to Rhodococcus,and AT6 to Gordonia. These bacterial strains could grow well in the medium with potassium nitrate as nitrogen source and sodium citrate as carbon source. Based on the enhanced nitrogen removal experiments of selected bacteria mixture for activated sludge,the inoculum amount of 5% was supposed to be proper. The mixed biomass suspension of selected strains with PVA immobilization was put into the concentric-circles reactor in order to study the characteristics of enhanced nitrogen removal after amplifying cultivation with inoculated amount of 5%. The experimental results show that the average removal efficiencies of ammonia nitrogen (NH3-N) and total nitrogen (TN) in the reactor enhanced with aerobic denitrifying bacteria using PVA are 92.18% and 79.14% respectively,increasing by 5.29% and 7.83% respectively compared with removal effects of control group without strains enhancement.
基金National Natural Science Foundation of China No.3017001
文摘A bacterium strain HS-03 was isolated from the activated sludge plant in a suburb of Wuhan city,China which has been found to be capable of aerobic denitrification.The effect of different inoculated amounts of pre-cultured media was analyzed.The denitrifying rates of this strain under aerobic and micro-anaerobic conditions were compared.The result indicated that the rate was almost not affected by the presence of oxygen.10m M nitrate was removed more than 90%in 36 hours by this bacterium in the specific medium.During the denitrifying process,nitrite was always kept at very low level.The denitrification potential of this bacterium was evaluated to treat artificial wastewater under fully aerobic conditions.Main biochemical and physiological features of this strain were characterized.The 16S rDNA sequence was compared with the published data in GenBank by using BLAST.The BLAST level of similarity to Pseudomonas stutzeri was 99.1%.These results of phenotype and genotype proved that the strain HS-03 was a new strain belonging to the species of P.stutzeri.
基金the Director of the School of Engineering and Science, Tecnológico de Monterrey, Campus Monterrey for his encouragement and financial supportthe financial support from CONACYT(Mexico)PhD scholarship No. 309171 for CCZ, SNI-C fellowship to RC and MR, FRAavesh green sustainability solutions S. De R. L. De. C. V. for their support
文摘2,4,6-trinitrotoluene(TNT) and its derivatives are nitrogen-containing aromatic compounds having chemical and thermal stability at ambient temperature and pressure. TNT has high toxicity and mutagenic activity to humans, plants and animals, thus decontamination processes are necessary. Many microorganisms are capable to bioremediate TNT such as bacteria from the genera Pseudomonas,Enterobacter, Rhodococcus, Mycobacterium, Clostridium and Desulfovibrio: fungus such as Phanerochate and Stropharia species are able to perform TNT biotransformation under aerobic and anaerobic conditions. In this work we review the state of TNT biodegradation by various routes: aerobic, anaerobic,combined, fungal, enzymatic, and bio-electrochemical.
基金Project(20090191120036) supported by the Fund of Doctoral Program of Ministry of Education,China
文摘A full-scale experimental study of treating mustard wastewater by the integrated bioreactor with designed scale of 1 000 m3/d is conducted combined with a demonstration project. The systematical researches on the efficiency of combined operation conditions of anaerobic-aerobic and anaerobic-aerobic-flocculation as well as chemical phosphorus removal of hypersaline mustard wastewater are conducted. The optimal operation condition and parameters in pretreatment of mustard wastewater in winter （the water temperature ranges 8-15 ~C） are determined： the anaerobic load is 3.0 kg （COD）/（m3.d）, the average COD and phosphate concentration of the inflow are respectively 3 883 mg/L and 35.53 mg/L and the dosage of flocculent （PAC） is 400 mg/L. The anaerobic-aerobic-flocculation combined operation condition and postpositive phosphorous removal with ferrous sulfate are employed. After treatment, the COD of the effluent is 470 mg/L and the average phosphate concentration is 5.09 mg/L. The effluent could achieve the third-level of Integrated Wastewater Discharge Standard （GB 8978--1996）.
基金Project(21071152) supported by the National Natural Science Foundation of China
文摘Molecular iodine was first utilized for direct oxidation of a-isophorone （α-IP） to ketoisophorone （KIP） with molecule oxygen at room temperature and the effects of amount of iodine, solvents and reaction time were investigated extensively. The optimized result shows that 70.2% conversion of a-isophorone and 82.6% selectivity of ketoisophorone are obtained with 15% iodine （molar fraction） in acetonitrile under photoirradiation for 5 h. Moreover, the possible mechanism is proposed.
基金Project(51078036) supported by the National Natural Science Foundation of China
文摘Laboratory experiments were conducted to investigate the transformation and performance of a granular sequence batch reactor(SBR) under the conventional organic loading rate(OLR) condition.Aerobic granules were successfully cultivated in a SBR by means of alternative feeding load combined with reducing settling time after 60 d operational period.Subsequently,the black fungal granules were presented in reactor because of the filamentous overgrowth on the surface of aerobic granules.A small amount of fungal granules had no effect on the performance of granular SBR.Aerobic granules completely vanished and fungal granules eventually became the dominant species in subsequent 90 d operation after granulation.The three-dimensional excitation emission matrix(EEM) spectra result shows that the extracellular polymeric substances(EPS) component in both granules has no much difference,whereas the content of EPS in fungal granules is higher than that in bacterial granules.Due to their low bioactivity,the chemical oxidation demand(COD) and NH4-N removal efficiencies gradually decrease from 90.4%–96.5% and 99.5% to 71.8% and 32.9% respectively while the fungal granules become dominant in the SBR.
基金Project(76132020) supported by the Post-Doctoral Science Fund of Central South University
文摘The amino acid Schiff base complex (Sal-AMBA-Mn) was prepared with p-amino-methylbenzoic acid, salicylaldehyde and Mn(OAc)2·4H2O. Its structures was characterized with IR and UV spectra. Oxygenation mechanism of the complex in N, N-dimethylformamide solution was investigated. The results show that lower temperature is in favor of the oxygenation, and energy, enthalpy and entropy are -3.8 kJ/mol, -4.2 J/mol and -161.44 J/(mol·K), respectively. In the presence of the manganese complex, dehydroepiandrosterone acetate is effectively oxidized by molecular oxygen and the corresponding enone 7-ketodehydroepiandrosterone acetate is obtained. The yield is 62.1% when the oxidation is carried out under the reaction conditions of 60 ℃, 2 MPa of O2 pressure, C5H5N as a solvent and molar ratio of the substrate to the complex of 1:10.
