This study investigates the simultaneous accumulation of S^(0) and NO_(2)^(-)during short-cut sulfur autotrophic denitrification(SSADN)in response to 0-35 mg/L hydroxylamine(NH_(2)OH)addition.At a dosage of 15 mg/L NH...This study investigates the simultaneous accumulation of S^(0) and NO_(2)^(-)during short-cut sulfur autotrophic denitrification(SSADN)in response to 0-35 mg/L hydroxylamine(NH_(2)OH)addition.At a dosage of 15 mg/L NH_(2)OH,the accumulation of NO_(2)^(-)-N peaked at 32.49±1.33 mg/L,which is 1.65 times higher than that of the control.The addition of NH_(2)OH facilitates the retention of S^(0) in the system.Enzyme assays indicated significant discrepancies in the enhanced NO_(2)^(-)-N reductase(NAR)and NO_(2)^(-)-N reductase(NIR)activities induced by NH_(2)OH are responsible for the excellent NO_(2)^(-)-N production.These results are supported by the corresponding NO_(3)^(-)-N reduction genes(napA,narG)and NO_(2)^(-)-N reduction genes(nirS,nirK).In addition,the abundance of sulfur oxidation genes(soxB)decreases with increasing NH_(2)OH dosage,inhibiting further oxidation of S^(0) to SO_(4)^(2-).The accumulation of NO_(2)^(-)-N and S^(0) increases from 45.8% and 36.8% to 70.04% and 52.52%,respectively,with the addition of 2 mg/L NH_(2)OH in the continuous-flow up-flow anaerobic sludge blanket(UASB)reactor.展开更多
A combined process consisting of a short-cut nitrification （SN） reactor and an anaerobic ammonium oxidation upflow anaerobic sludge bed （ANAMMOX） reactor was developed to treat the diluted effluent from an upflow ...A combined process consisting of a short-cut nitrification （SN） reactor and an anaerobic ammonium oxidation upflow anaerobic sludge bed （ANAMMOX） reactor was developed to treat the diluted effluent from an upflow anaerobic sludge bed （UASB） reactor treating high ammonium municipal landfill leachate.The SN process was performed in an aerated upflow sludge bed （AUSB） reactor （working volume 3.05 L）,treating about 50% of the diluted raw wastewater.The ammonium removal efficiency and the ratio of NO 2 N to NOx-N in the effluent were both higher than 80%,at a maximum nitrogen loading rate of 1.47 kg/（m 3 ·day）.The ANAMMOX process was performed in an UASB reactor （working volume 8.5 L）,using the mix of SN reactor effluent and diluted raw wastewater at a ratio of 1：1.The ammonium and nitrite removal efficiency reached over 93% and 95%,respectively,after 70-day continuous operation,at a maximum total nitrogen loading rate of 0.91 kg/（m 3 ·day）,suggesting a successful operation of the combined process.The average nitrogen loading rate of the combined system was 0.56 kg/（m 3 ·day）,with an average total inorganic nitrogen removal efficiency 87%.The nitrogen in the effluent was mostly nitrate.The results provided important evidence for the possibility of applying SN-ANAMMOX after UASB reactor to treat municipal landfill leachate.展开更多
To investigate the characteristics and metabolic mechanism of short-cut denitrifying phospho- rus-removing bacteria （SDPB） that are capable of enhanced biological phosphorus removal （EBPR） using nitrite as an elec...To investigate the characteristics and metabolic mechanism of short-cut denitrifying phospho- rus-removing bacteria （SDPB） that are capable of enhanced biological phosphorus removal （EBPR） using nitrite as an electron acceptor, an aerobic/anoxic sequencing batch reactor was operated under three phases. An SDPB-strain YC was screened after the sludge enrichment and was identified by morphological, physiological, biochemical properties and 16S rDNA gene sequence analysis. Denitrifying phosphorus-removing experiments were conducted to study anaerobic and anoxic metabolic mechanisms by analyzing the changes of chemical oxygen demand （COD）, phosphate, nitrite, poly-fl-hydroxybutyrate （PHB）, and glycogen. The results show that strain YC is a non-fermentative SDPB similar to Paracoccus denitrificans. As a kind of non-fermentative bacteria, the energy of strain YC was mainly generated from phosphorus release （96.2%） under anaerobic conditions with 0.32 mg P per mg synthesized PHB. Under anoxic conditions, strain YC accumulated 0.45 mg P per mg degraded PHB, which produced most of energy for phosphate accumulation （91.3%） and a little for glycogen synthesis （8.7%）. This metabolic mechanism of strain YC is different from that of traditional phosphorus-accumulating organisms （PAOs）. It is also found that PHB, a kind of intracellular polymer, plays a very important role in denitrifying and accumulating phosphorus by supplying sufficient energy for phosphorous accumulation and carbon sources for denitrification. Therefore, monitoring AP/APHB and ANO2 -N/APHB is more necessary than monitoring AP/ACOD, ANO2 -N/ACOD, or AP / ANO2 -N.展开更多
A system combining granular activated carbon and powdered activated carbon technologies along with shortcut biological nitrogen removal （GAC-PACT-SBNR） was developed to enhance total nitrogen （TN） removal for anae...A system combining granular activated carbon and powdered activated carbon technologies along with shortcut biological nitrogen removal （GAC-PACT-SBNR） was developed to enhance total nitrogen （TN） removal for anaerobically treated coal gasification wastewater with less need for external carbon resources. The TN removal efficiency in SBNR was significantly improved by introducing the effluent from the GAC process into SBNR during the anoxic stage, with removal percentage increasing from 43.8%49.6% to 68.8%-75.8%. However, the TN removal rate decreased with the progressive deterioration of GAC adsorption. After adding activated sludge to the GAG compartment, the granular carbon had a longer service-life and the demand for external carbon resources became lower. Eventually, the TN removal rate in SBNR was almost constant at approx. 43.3%, as compared to approx. 20.0% before seeding with sludge. In addition, the production of some alkalinity during the denitrification resulted in a net savings in alkalinity requirements for the nitrification reaction and refractory chemical oxygen demand （COD） degradation by autotrophic bacteria in SBNR under oxic conditions. PACT showed excellent resilience to increasing organic loadings. The microbial community analysis revealed that the PACT had a greater variety of bacterial taxons and the dominant species associated with the three compartments were in good agreement with the removal of typical pollutants. The study demonstrated that pre-adsorption by the GAC-sludge process could be a technically and economically feasible method to enhance TN removal in coal gasification wastewater （CGW）.展开更多
[Objectives]To further study the technology of short-cut flowering branches for Guire No.82 Mango,adjust its harvest time,increase yield and improve fruit quality,and increase the economic benefits of mango production...[Objectives]To further study the technology of short-cut flowering branches for Guire No.82 Mango,adjust its harvest time,increase yield and improve fruit quality,and increase the economic benefits of mango production.[Methods]The experiment of short-cut flowering branches was carried out for Guire No.82 Mango.[Results]At the initial flowering stage and full flowering stage of the primary inflorescence,with short-cut flowering branches and corresponding cultivation techniques,Guire No.82 Mango was easy to extract regenerated inflorescences.Compared with the control group,the flowering period of the regenerated inflorescences was delayed by 30-35 d and 40-50 d,respectively;the harvest time was delayed by 30 and 40 d,respectively;the yield significantly increased by 1.63 times and 2.25 times,respectively;compared with the control group,the number of fruits with embryo increased significantly,which were 1.39 and 2.25 times of the control,respectively;there was no significant difference in the fruit quality at the harvest time.[Conclusions]Short-cut flowering branches at the initial flowering stage and full flowering stage of the primary inflorescence is an effective measure to delay the marketing time of Guire No.82 Mango.展开更多
Water scarcity is a pressing issue that threatens sustainable development worldwide,especially in regions like China,where natural freshwater resources are increasingly strained by rapid urbanization,climate change,an...Water scarcity is a pressing issue that threatens sustainable development worldwide,especially in regions like China,where natural freshwater resources are increasingly strained by rapid urbanization,climate change,and ecological demands.While seawater desalination offers a strategic freshwater augmentation pathway,its large-scale application remains constrained by challenges including public perception gaps(eg,how to understand water scarcity),technoeconomic barriers,and developmental paradigm controversies.Through comprehensive analysis grounded in firstprinciples thinking,this research re-evaluates seawater desalination as a transformative solution to water scarcity,incorporating assessments compared to conventional water supply systems.This study proposes a novel“100-Kilometer Coastal Desalination for Short-cut water cycle(100K-CDS)”strategy for China,leveraging its extensive coastline to industrialize water production.Key findings reveal that modern reverse osmosis technology has achieved significant cost reductions through technological advancement and economies of scale.The integration of renewable energy sources could reduce desalination’s carbon footprint by 57.5%~98.3%compared to conventional systems.Implementing coastal desalination strategies will not only effectively alleviate regional water demands of coast areas,which account for 40%of the nation’s population and over 50%of its GDP.This research contributes a paradigm-shifting framework for treating desalinated freshwater as a manufacturable resource rather than a finite natural commodity,offering promotable insights for water-scarce regions worldwide and advancing global water sustainability through industrial-scale desalination.展开更多
Biological nitrogen removal of wastewater with low COD/N ratio could be enhanced by the addition of wasted sludge fermentation liquid(SFL),but the performance is usually limited by the introducing ammonium.In this stu...Biological nitrogen removal of wastewater with low COD/N ratio could be enhanced by the addition of wasted sludge fermentation liquid(SFL),but the performance is usually limited by the introducing ammonium.In this study,the process of using SFL was successfully improved by involving anammox process.Real municipal wastewater with a low C/N ratio of 2.8–3.4 was treated in a sequencing batch reactor(SBR).The SBR was operated under anaerobic-aerobic-anoxic(AOA)mode and excess SFL was added into the anoxic phase.Stable short-cut nitrification was achieved after 46d and then anammox sludge was inoculated.In the stable period,effluent total inorganic nitrogen(TIN)was less than 4.3 mg/L with removal efficiency of 92.3%.Further analysis suggests that anammox bacteria,mainly affiliated with Candidatus_Kuenenia,successfully reduced the external ammonia from the SFL and contributed approximately 28%–43%to TIN removal.Overall,this study suggests anammox could be combined with SFL addition,resulting in a stable enhanced nitrogen biological removal.展开更多
Friction between two contacting surfaces is studied extensively.One of the k n o w n friction theories is Amontons,law which states that the friction force is proportional to the normal force.However,Amontons7 law has...Friction between two contacting surfaces is studied extensively.One of the k n o w n friction theories is Amontons,law which states that the friction force is proportional to the normal force.However,Amontons7 law has been found to be invalid for elastomers.In the present study,the validity of Amontons7 law for short-cut aramid fiber reinforced elastomers is studied.Two types of fillers are used to reinforce the elastomers,namely highly dispersible silica and short-cut aramid fibers.Short-cut aramid fibers with two different surface treatments are used,namely non-reactive fibers with standard oily finish(SF-fibers)and fibers treated with an epoxy coating(EF-fibers).A pin-on-disc tribometer is used to investigate the frictional behavior of the composites in sliding contact with a granite counter surface.The results show that,after the run-in phase,Amontons,law is valid for those composites that are reinforced by short-cut aramid fibers(without reinforcing filler,i.e.,silica)if the contact pressure is below a threshold value.However,once the contact pressure exceeds this threshold value,Amontons'law will be invalid.The threshold contact pressure of the composites containing EF-fibers is higher than of the composites containing SF-fibers.The composites that are reinforced by silica and short-cut aramid fibers do not follow Amontons7 law.展开更多
基金supported by the Shandong Provincial Natural Science Foundation(No.ZR2019MEE038,ZR202110260011)the Scientific research project of Xinjiang oilfield company(No.2022C4004)the Qingdao West-Coast Economic New Area Scientific and Technological Project of the special open competition mechanism to select the best candidates(2022-14).
文摘This study investigates the simultaneous accumulation of S^(0) and NO_(2)^(-)during short-cut sulfur autotrophic denitrification(SSADN)in response to 0-35 mg/L hydroxylamine(NH_(2)OH)addition.At a dosage of 15 mg/L NH_(2)OH,the accumulation of NO_(2)^(-)-N peaked at 32.49±1.33 mg/L,which is 1.65 times higher than that of the control.The addition of NH_(2)OH facilitates the retention of S^(0) in the system.Enzyme assays indicated significant discrepancies in the enhanced NO_(2)^(-)-N reductase(NAR)and NO_(2)^(-)-N reductase(NIR)activities induced by NH_(2)OH are responsible for the excellent NO_(2)^(-)-N production.These results are supported by the corresponding NO_(3)^(-)-N reduction genes(napA,narG)and NO_(2)^(-)-N reduction genes(nirS,nirK).In addition,the abundance of sulfur oxidation genes(soxB)decreases with increasing NH_(2)OH dosage,inhibiting further oxidation of S^(0) to SO_(4)^(2-).The accumulation of NO_(2)^(-)-N and S^(0) increases from 45.8% and 36.8% to 70.04% and 52.52%,respectively,with the addition of 2 mg/L NH_(2)OH in the continuous-flow up-flow anaerobic sludge blanket(UASB)reactor.
基金supported by the Special Fundof State Key Joint Laboratory of Environment Simulation and Pollution Control,China (No. 08Y03ESPCT)the Key Projects in the National Science & Technology Pillar Program in the Eleventh Five-Year Plan Period of China(No. 2006BACl9B01)
文摘A combined process consisting of a short-cut nitrification （SN） reactor and an anaerobic ammonium oxidation upflow anaerobic sludge bed （ANAMMOX） reactor was developed to treat the diluted effluent from an upflow anaerobic sludge bed （UASB） reactor treating high ammonium municipal landfill leachate.The SN process was performed in an aerated upflow sludge bed （AUSB） reactor （working volume 3.05 L）,treating about 50% of the diluted raw wastewater.The ammonium removal efficiency and the ratio of NO 2 N to NOx-N in the effluent were both higher than 80%,at a maximum nitrogen loading rate of 1.47 kg/（m 3 ·day）.The ANAMMOX process was performed in an UASB reactor （working volume 8.5 L）,using the mix of SN reactor effluent and diluted raw wastewater at a ratio of 1：1.The ammonium and nitrite removal efficiency reached over 93% and 95%,respectively,after 70-day continuous operation,at a maximum total nitrogen loading rate of 0.91 kg/（m 3 ·day）,suggesting a successful operation of the combined process.The average nitrogen loading rate of the combined system was 0.56 kg/（m 3 ·day）,with an average total inorganic nitrogen removal efficiency 87%.The nitrogen in the effluent was mostly nitrate.The results provided important evidence for the possibility of applying SN-ANAMMOX after UASB reactor to treat municipal landfill leachate.
基金Supported by the Nafional Natural Science Foundation of China （51078008）, the Natural Science Foundation of Guangdong Province （06022869, 07003251）, and the National Key Scientific and Technological Project Water Pollution Control and Treatment （2008ZX07211-003, 2009ZX07314-009-003）.
文摘To investigate the characteristics and metabolic mechanism of short-cut denitrifying phospho- rus-removing bacteria （SDPB） that are capable of enhanced biological phosphorus removal （EBPR） using nitrite as an electron acceptor, an aerobic/anoxic sequencing batch reactor was operated under three phases. An SDPB-strain YC was screened after the sludge enrichment and was identified by morphological, physiological, biochemical properties and 16S rDNA gene sequence analysis. Denitrifying phosphorus-removing experiments were conducted to study anaerobic and anoxic metabolic mechanisms by analyzing the changes of chemical oxygen demand （COD）, phosphate, nitrite, poly-fl-hydroxybutyrate （PHB）, and glycogen. The results show that strain YC is a non-fermentative SDPB similar to Paracoccus denitrificans. As a kind of non-fermentative bacteria, the energy of strain YC was mainly generated from phosphorus release （96.2%） under anaerobic conditions with 0.32 mg P per mg synthesized PHB. Under anoxic conditions, strain YC accumulated 0.45 mg P per mg degraded PHB, which produced most of energy for phosphate accumulation （91.3%） and a little for glycogen synthesis （8.7%）. This metabolic mechanism of strain YC is different from that of traditional phosphorus-accumulating organisms （PAOs）. It is also found that PHB, a kind of intracellular polymer, plays a very important role in denitrifying and accumulating phosphorus by supplying sufficient energy for phosphorous accumulation and carbon sources for denitrification. Therefore, monitoring AP/APHB and ANO2 -N/APHB is more necessary than monitoring AP/ACOD, ANO2 -N/ACOD, or AP / ANO2 -N.
基金supported by Sino-Dutch Research Program (SDRP2011-2015)the independent subject sponsored by State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (No. 2013DX10)
文摘A system combining granular activated carbon and powdered activated carbon technologies along with shortcut biological nitrogen removal （GAC-PACT-SBNR） was developed to enhance total nitrogen （TN） removal for anaerobically treated coal gasification wastewater with less need for external carbon resources. The TN removal efficiency in SBNR was significantly improved by introducing the effluent from the GAC process into SBNR during the anoxic stage, with removal percentage increasing from 43.8%49.6% to 68.8%-75.8%. However, the TN removal rate decreased with the progressive deterioration of GAC adsorption. After adding activated sludge to the GAG compartment, the granular carbon had a longer service-life and the demand for external carbon resources became lower. Eventually, the TN removal rate in SBNR was almost constant at approx. 43.3%, as compared to approx. 20.0% before seeding with sludge. In addition, the production of some alkalinity during the denitrification resulted in a net savings in alkalinity requirements for the nitrification reaction and refractory chemical oxygen demand （COD） degradation by autotrophic bacteria in SBNR under oxic conditions. PACT showed excellent resilience to increasing organic loadings. The microbial community analysis revealed that the PACT had a greater variety of bacterial taxons and the dominant species associated with the three compartments were in good agreement with the removal of typical pollutants. The study demonstrated that pre-adsorption by the GAC-sludge process could be a technically and economically feasible method to enhance TN removal in coal gasification wastewater （CGW）.
基金Supported by Project of Guangxi Science and Technology Program"Demonstration and Extension of Technology for Postponing Harvest time of Mango"(Gui Ke AB17292084)Agricultural Technology Research Project of Baise City。
文摘[Objectives]To further study the technology of short-cut flowering branches for Guire No.82 Mango,adjust its harvest time,increase yield and improve fruit quality,and increase the economic benefits of mango production.[Methods]The experiment of short-cut flowering branches was carried out for Guire No.82 Mango.[Results]At the initial flowering stage and full flowering stage of the primary inflorescence,with short-cut flowering branches and corresponding cultivation techniques,Guire No.82 Mango was easy to extract regenerated inflorescences.Compared with the control group,the flowering period of the regenerated inflorescences was delayed by 30-35 d and 40-50 d,respectively;the harvest time was delayed by 30 and 40 d,respectively;the yield significantly increased by 1.63 times and 2.25 times,respectively;compared with the control group,the number of fruits with embryo increased significantly,which were 1.39 and 2.25 times of the control,respectively;there was no significant difference in the fruit quality at the harvest time.[Conclusions]Short-cut flowering branches at the initial flowering stage and full flowering stage of the primary inflorescence is an effective measure to delay the marketing time of Guire No.82 Mango.
文摘Water scarcity is a pressing issue that threatens sustainable development worldwide,especially in regions like China,where natural freshwater resources are increasingly strained by rapid urbanization,climate change,and ecological demands.While seawater desalination offers a strategic freshwater augmentation pathway,its large-scale application remains constrained by challenges including public perception gaps(eg,how to understand water scarcity),technoeconomic barriers,and developmental paradigm controversies.Through comprehensive analysis grounded in firstprinciples thinking,this research re-evaluates seawater desalination as a transformative solution to water scarcity,incorporating assessments compared to conventional water supply systems.This study proposes a novel“100-Kilometer Coastal Desalination for Short-cut water cycle(100K-CDS)”strategy for China,leveraging its extensive coastline to industrialize water production.Key findings reveal that modern reverse osmosis technology has achieved significant cost reductions through technological advancement and economies of scale.The integration of renewable energy sources could reduce desalination’s carbon footprint by 57.5%~98.3%compared to conventional systems.Implementing coastal desalination strategies will not only effectively alleviate regional water demands of coast areas,which account for 40%of the nation’s population and over 50%of its GDP.This research contributes a paradigm-shifting framework for treating desalinated freshwater as a manufacturable resource rather than a finite natural commodity,offering promotable insights for water-scarce regions worldwide and advancing global water sustainability through industrial-scale desalination.
基金supported by Beijing Municipal Science&Technology Project(Z181100005518006)National Natural Science Foundation of China(Grant No.21777005)and R&D Program of Beijing Municipal Education commission.
文摘Biological nitrogen removal of wastewater with low COD/N ratio could be enhanced by the addition of wasted sludge fermentation liquid(SFL),but the performance is usually limited by the introducing ammonium.In this study,the process of using SFL was successfully improved by involving anammox process.Real municipal wastewater with a low C/N ratio of 2.8–3.4 was treated in a sequencing batch reactor(SBR).The SBR was operated under anaerobic-aerobic-anoxic(AOA)mode and excess SFL was added into the anoxic phase.Stable short-cut nitrification was achieved after 46d and then anammox sludge was inoculated.In the stable period,effluent total inorganic nitrogen(TIN)was less than 4.3 mg/L with removal efficiency of 92.3%.Further analysis suggests that anammox bacteria,mainly affiliated with Candidatus_Kuenenia,successfully reduced the external ammonia from the SFL and contributed approximately 28%–43%to TIN removal.Overall,this study suggests anammox could be combined with SFL addition,resulting in a stable enhanced nitrogen biological removal.
基金This work is part of the Research Program of the Dutch Polymer Institute DPI,The Netherlands(Project No.#782).
文摘Friction between two contacting surfaces is studied extensively.One of the k n o w n friction theories is Amontons,law which states that the friction force is proportional to the normal force.However,Amontons7 law has been found to be invalid for elastomers.In the present study,the validity of Amontons7 law for short-cut aramid fiber reinforced elastomers is studied.Two types of fillers are used to reinforce the elastomers,namely highly dispersible silica and short-cut aramid fibers.Short-cut aramid fibers with two different surface treatments are used,namely non-reactive fibers with standard oily finish(SF-fibers)and fibers treated with an epoxy coating(EF-fibers).A pin-on-disc tribometer is used to investigate the frictional behavior of the composites in sliding contact with a granite counter surface.The results show that,after the run-in phase,Amontons,law is valid for those composites that are reinforced by short-cut aramid fibers(without reinforcing filler,i.e.,silica)if the contact pressure is below a threshold value.However,once the contact pressure exceeds this threshold value,Amontons'law will be invalid.The threshold contact pressure of the composites containing EF-fibers is higher than of the composites containing SF-fibers.The composites that are reinforced by silica and short-cut aramid fibers do not follow Amontons7 law.
