In Alzheimer’s disease,the transporter P-glycoprotein is responsible for the clearance of amyloid-βin the brain.Amyloid-βcorrelates with the sphingomyelin metabolism,and sphingomyelin participates in the regulation...In Alzheimer’s disease,the transporter P-glycoprotein is responsible for the clearance of amyloid-βin the brain.Amyloid-βcorrelates with the sphingomyelin metabolism,and sphingomyelin participates in the regulation of P-glycoprotein.The amyloid cascade hypothesis describes amyloid-βas the central cause of Alzheimer’s disease neuropathology.Better understanding of the change of P-glycoprotein and sphingomyelin along with amyloid-βand their potential association in the pathological process of Alzheimer’s disease is critical.Herein,we found that the expression of P-glycoprotein in APP/PS1 mice tended to increase with age and was significantly higher at 9 and 12 months of age than that in wild-type mice at comparable age.The functionality of P-glycoprotein of APP/PS1 mice did not change with age but was significantly lower than that of wild-type mice at 12 months of age.Decreased sphingomyelin levels,increased ceramide levels,and the increased expression and activity of neutral sphingomyelinase 1 were observed in APP/PS1 mice at 9 and 12 months of age compared with the levels in wild-type mice.Similar results were observed in the Alzheimer’s disease mouse model induced by intracerebroventricular injection of amyloid-β1-42 and human cerebral microvascular endothelial cells treated with amyloid-β1-42.In human cerebral microvascular endothelial cells,neutral sphingomyelinase 1 inhibitor interfered with the changes of sphingomyelin metabolism and P-glycoprotein expression and functionality caused by amyloid-β1-42 treatment.Neutral sphingomyelinase 1 regulated the expression and functionality of P-glycoprotein and the levels of sphingomyelin and ceramide.Together,these findings indicate that neutral sphingomyelinase 1 regulates the expression and function of P-glycoprotein via the sphingomyelin/ceramide pathway.These studies may serve as new pursuits for the development of anti-Alzheimer’s disease drugs.展开更多
近些年,伴随着国家积极的推动新医疗改革措施落地,在此背景之下,按照患者疾病诊断相关分组(Diagnosis Related Groups,DRG)成为了新医改的重点内容。DRG这种支付结算方式使得现阶段国内的公立医院在资金以及运营管理压力方面显著增加,...近些年,伴随着国家积极的推动新医疗改革措施落地,在此背景之下,按照患者疾病诊断相关分组(Diagnosis Related Groups,DRG)成为了新医改的重点内容。DRG这种支付结算方式使得现阶段国内的公立医院在资金以及运营管理压力方面显著增加,同时也为国内医院的经营以及管理工作带来了较大的挑战。为此,本文对DRG支付模式在公立医院的经营以及管理服务方面所产生的问题进行分析,并以此为基础,提出了几点针对性的改善策略,以期为行业人员提供参考。展开更多
A numerical model was established to predict and optimise the chemical cleaning process of Polyvinylidene Fluo- ride （PVDF） Ultrafiltration （UF） membranes with the results from the experiment that applied the Resp...A numerical model was established to predict and optimise the chemical cleaning process of Polyvinylidene Fluo- ride （PVDF） Ultrafiltration （UF） membranes with the results from the experiment that applied the Response Sur- face Method （RSM） and Central Composite Design （CCD）. The factors considered in the experimental design were sodium hydroxide （NaOH） concentration, sodium bypochlorite concentration （NaCIO）, citric acid concentration and cleaning duration, The interactions between the factors were investigated with the numerical model. Humic acid （20 mg· L-1） was used as the model foulant, and chemical enhanced backflush （CEB） was employed to sim- ulate the chemical cleaning process. The concentrations of sodium hydroxide, sodium hypochlorite, citric acid and cleaning duration tested during the experiments were in the range of 0.1%-0.3% 100-300 mg· L-1 1%-3% and 0.5-1.5 h, respectively. Among the variables, the sodium hypochlorite concentration and the cleaning dura- tion showed a positive relationship involving the increased efficiency of the chemical cleaning. The chemical cleaning efficiency was hardly improved with increasing concentrations of sodium hydroxide. However, the data was sharply decreased when at a low level of sodium hydroxide concentration. In total, 54 sets of cleaning schemes with 80% to 100K cleaning efficiency were observed with the R＆M model after calibration.展开更多
Ultrafiltration(UF)has been increasingly implemented in drinking water treatment plants;however,algae and their secretions can cause severe membrane fouling and pose great challenges to UF in practice.In this study,a ...Ultrafiltration(UF)has been increasingly implemented in drinking water treatment plants;however,algae and their secretions can cause severe membrane fouling and pose great challenges to UF in practice.In this study,a simple and practical chemically enhanced backwashing(CEB)process was developed to address such issues using various cleaning reagents,including sodium hypochlorite(NaClO),sodium chloride(NaCl),sodium hydroxide(NaOH),sodium citrate,and their combinations.The results indicate that the type of chemical played a fundamental role in alleviating the hydraulically irreversible membrane fouling(HIMF),with NaClO as the best-performing reagent,followed by NaCl.Furthermore,a CEB process using a combination of NaClO with NaCl,NaOH,or sodium citrate delivered little improvement in the alleviation of membrane fouling compared with NaClO alone.The optimized dosage and dosing frequency of NaClO were 10 mg·L^(-1) two times per day.Long-term pilot-scale and full-scale experiments further verified the feasibility of the CEB process in relieving algae-derived membrane fouling.Compared with the conventional hydraulic backwashing without chemical involvement,the CEB process can effectively remove the organic foulants including biopolymers,humic substances,and proteinlike substances by means of oxidization,thereby weakening the cohesive forces between the organic foulants and the membrane surface.Therefore,the CEB process can efficiently alleviate the algae-related membrane fouling with lower chemical consumption,and is proposed as an alternative to control membrane fouling in treating the algae-containing surface water.展开更多
Water reuse is an effective way to solve the issues of current wastewater increments and water resource scarcity.Ultrafiltration,a promising method for water reuse,has the characteristics of low energy consumption,eas...Water reuse is an effective way to solve the issues of current wastewater increments and water resource scarcity.Ultrafiltration,a promising method for water reuse,has the characteristics of low energy consumption,easy operation,and high adaptability to coupling with other water treatment processes.However,emerging organic contaminants(EOCs)in municipal wastewater cannot be effectively intercepted by ultrafiltration,which poses significant challenges to the effluent quality and sustainability of ultrafiltration process.Here,we develop a cobalt single-atom catalyst-tailored ceramic membrane(Co1-NCNT-CM)in conjunction with an activated peroxymonosulfate(PMS)system,achieving excellent EOCs degradation and anti-fouling performance.An interfacial reaction mechanism effectively mitigates membrane fouling through a repulsive interaction with natural organic matter.The generation of singlet oxygen at the Co-N3-C active sites through a catalytic pathway(PMS/PMS*/OH*/O*/OO*/1 O_(2))exhibits selective oxidation of phenols and sulfonamides,achieving>90%removal rates.Our findings elucidate a multi-layered functional architecture within the Co1-NCNT-CM/PMS system,responsible for its superior performance in organic decontamination and membrane maintenance during secondary effluent treatment.It highlights the power of integrating Co1-NCNT-CM/PMS systems in advanced wastewater treatment frameworks,specifically for targeted EOCs removal,heralding a new direction for sustainable water management.展开更多
Efficient and accurate strength analysis of bolted connections is essential in analyzing the integral thermal protection system（ITPS） of hypersonic vehicles, since the system bears severe loads and structural failur...Efficient and accurate strength analysis of bolted connections is essential in analyzing the integral thermal protection system（ITPS） of hypersonic vehicles, since the system bears severe loads and structural failures usually occur at the connections. Investigations of composite mechanical properties used in ITPS are still in progress as the architecture of the composites is complex. A new method is proposed in this paper for strength analysis of bolted connections by investigating the elastic behavior and failure strength of three-dimensional C/C orthogonal composites used in ITPS. In this method a multi-scale finite element method incorporating the global–local method is established to ensure high efficiency in macro-scale and precision in meso-scale in analysis.Simulation results reveal that predictions of material properties show reasonable accuracy compared with test results. And the multi-scale method can analyze the strength of connections efficiently and accurately.展开更多
Energy uncoupling is often used for sludge reduction because it is easy to operate and does not require a significant amount of extra equipments(i.e.no additional tank required).However,over time the supernatant extra...Energy uncoupling is often used for sludge reduction because it is easy to operate and does not require a significant amount of extra equipments(i.e.no additional tank required).However,over time the supernatant extracted using this method can deteriorate,ultimately requiring further treatment.The purpose of this study was to determine the effect of using a low-pressure ultrafiltration membrane process for sludge water recovery after the sludge had undergone an energy uncoupling treatment(using 3,3’,4’,5-tetrachlorosalicylanilide(TCS)).Energy uncoupling was found to break apart sludge floe by reducing extracellular polymeric substances(EPS)and adenosine triphosphate(ATP)content.Analysis of supernatant indicated that when energy uncoupling and membrane filtration were coapplied and the TCS dosage was below 30 mg/L,there was no significant deterioration in organic component removal.However,ammonia and phosphate concentrations were found to increase as the concentration of TCS added increased.Additionally,due to low sludge concentrations and EPS contents,addition of 30-60 mg/L TCS during sludge reduction increased the permeate flux(two times higher than the control)and decreased the hydraulic reversible and cake layer resistances.In contrast,high dosage of TCS aggravated membrane fouling by forming compact fouling layers.In general,this study found that the co-application of energy uncoupling and membrane filtration processes represents an effective alternative method for simultaneous sludge reduction and sludge supernatant recovery.展开更多
The gravity-driven membrane bioreactor(MBR)system is promising for decentralized sewage treatment because of its low energy consumption and maintenance requirements.However,the growing sludge not only increases membra...The gravity-driven membrane bioreactor(MBR)system is promising for decentralized sewage treatment because of its low energy consumption and maintenance requirements.However,the growing sludge not only increases membrane fouling,but also augments operational complexities(sludge discharge).We added the metabolic uncoupler 3,3’,4f,5-tetrachlorosalicylanilide(TC$)to the system to deal with the mentioned issues.Based on the results,TCS addition effectively decreased sludge ATP and sludge yield(reduced by 50%).Extracellular polymeric substances(EPS;proteins and polysaccharides)decreased with the addition of TCS and were transformed into dissolved soluble microbial products(SMPs)in the bulk solution,leading to the break of sludge floes into small fragments.Permeability was increased by more than two times,reaching 60-70 L/m2/h bar when 10-30 mg/L TCS were added,because of the reduced suspended sludge and the formation of a thin cake layer with low EPS levels.Resistance analyses confirmed that appropriate dosages of TCS primarily decreased the cake layer and hydraulically reversible resistances.Permeability decreased at high dosage(50 mg/L)due to the release of excess sludge fragments and SMP into the supernatant,with a thin but more compact fouling layer with low bioactivity developing on the membrane surface,causing higher cake layer and pore blocking resistances.Our study provides a fundamental understanding of how a metabolic uncoupler affects the sludge and bio-fouling layers at different dosages,with practical relevance for in situ sludge reduction and membrane fouling alleviation in MBR systems.展开更多
Drinking water treatment sludge,characterized as accumulated suspended solids and organic and inorganic matter,is produced in large quantities during the coagulation process.The proper disposal,regeneration or reuse o...Drinking water treatment sludge,characterized as accumulated suspended solids and organic and inorganic matter,is produced in large quantities during the coagulation process.The proper disposal,regeneration or reuse of sludge is,therefore,a significant environmental issue.Reused sludge at low temperatures is an alternative method to enhance traditional coagulation efficiency.In the present study,the recycling mass of mixed sludge and properties of raw water （such as pH and turbidity） were systematically investigated to optimize coagulation efficiency.We determined that the appropriate dosage of mixed sludge was 60 mL/L,effective initial turbidity ranges were below 45.0 NTU,and optimal pH for DOMs and turbidity removal was 6.5-7.0 and 8.0,respectively.Furthermore,by comparing the flocs characteristics with and without recycling sludge,we found that floc structures with sludge were more irregular with average size growth to 64.7 μm from 48.1 μm.Recycling sludge was a feasible and successful method for enhancing pollutants removal,and the more irregular flocs structure after recycling might be caused by breakage of reused flocs and incorporation of powdered activated carbon into larger flocs structure.Applied during the coagulation process,recycling sludge could be significant for the treatment of low temperature and micro-polluted source water.展开更多
The discrepancy of indoleamine 2,3-dioxygenase 1(IDO1)function in atherosclerosis has been noted.Compared to the protective effect of IDO1 against established atherogenesis,the role of IDO1 in the developmental proces...The discrepancy of indoleamine 2,3-dioxygenase 1(IDO1)function in atherosclerosis has been noted.Compared to the protective effect of IDO1 against established atherogenesis,the role of IDO1 in the developmental process of atherosclerosis is still unclear.Here,the expression patterns and activities of IDO1 and its isoenzyme tryptophan 2,3-dioxygenase(TDO)in aortas and blood samples of patients with atherosclerosis were investigated.IDO1 and TDO were colocalized with CD3-positive lymphocytes and CD68-positive macrophages in atherosclerotic lesions.The expression and activity of IDO1 and TDO increased with the grade of the histological classification in early atherosclerosis(grade I,II),but the increase did not continue in advanced atherosclerosis(grade III).Treatment of THP-1 macrophages(THP-M)with oxidized low-density lipoprotein(oxLDL)induced the expression of IDO1 via the PI3K/Akt/NF-κB pathway,indicating the potential function of IDO1 in foam cells.Before and after treatment with oxLDL on THP-M,IFN-γ-induced IDO1 exhibited different degrees of promotion on foaming,inflammatory factor production and cell apoptosis.Finally,we found that the IDO1 inhibitor 1-methyl-tryptophan could elevate the high-density lipoprotein cholesterol level in serum and reduce the area of the aortic atherosclerotic lesions in high-fat diet-fed ApoE−/−mice.Our study indicated that IDO1 played a complicated and unfixed role in the entire process of atherogenesis,despite the atheroprotective role in established atherosclerosis.IDO1 also had proatherosclerotic functions in the developmental stages of atherosclerosis.Modulation of IDO1 could be a good method for alleviating atherosclerosis.展开更多
As a routine measurement to alleviate membrane fouling, hydraulic cleaning is of great significance for the steady operation of ultrafiltration（UF） systems in water treatment processes. In this work, a comparative s...As a routine measurement to alleviate membrane fouling, hydraulic cleaning is of great significance for the steady operation of ultrafiltration（UF） systems in water treatment processes. In this work, a comparative study was performed to investigate the effects of the composition of backwash water on the hydraulic cleaning performance of UF membranes fouled by humic acid（HA）. Various types of backwash water, including UF permeate, Milli-Q water, Na Cl solution, CaCl_2 solution and HA solution, were compared in terms of hydraulically irreversible fouling index, total surface tension and residual HA. The results indicated that Milli-Q water backwash was superior to UF permeate backwash in cleaning HA-fouled membranes, and the backwash water containing Na＋or HA outperformed Milli-Q water in alleviating HA fouling. On the contrary, the presence of Ca^（2＋） in backwash water significantly decreased the backwash efficiency. Moreover, Ca^（2＋） played an important role in foulant removal, and the residual HA content closely related to the residual Ca^（2＋） content.Mechanism analysis suggested that the backwash process may involve fouling layer swelling, ion exchange, electric double layer release and competitive complexation. Ion exchange and competitive complexation played significant roles in the efficient hydraulic cleaning associated with Na＋and HA, respectively.展开更多
基金supported by the National Key Research and Development Program of ChinaNos.2021YFC2 701800 and 2021YFC2 701805 (to QY)+2 种基金Open Research Fund of State Key Laboratory of Genetic EngineeringFudan UniversityNo.SKLGE-21 19 (to TXH and QY)
文摘In Alzheimer’s disease,the transporter P-glycoprotein is responsible for the clearance of amyloid-βin the brain.Amyloid-βcorrelates with the sphingomyelin metabolism,and sphingomyelin participates in the regulation of P-glycoprotein.The amyloid cascade hypothesis describes amyloid-βas the central cause of Alzheimer’s disease neuropathology.Better understanding of the change of P-glycoprotein and sphingomyelin along with amyloid-βand their potential association in the pathological process of Alzheimer’s disease is critical.Herein,we found that the expression of P-glycoprotein in APP/PS1 mice tended to increase with age and was significantly higher at 9 and 12 months of age than that in wild-type mice at comparable age.The functionality of P-glycoprotein of APP/PS1 mice did not change with age but was significantly lower than that of wild-type mice at 12 months of age.Decreased sphingomyelin levels,increased ceramide levels,and the increased expression and activity of neutral sphingomyelinase 1 were observed in APP/PS1 mice at 9 and 12 months of age compared with the levels in wild-type mice.Similar results were observed in the Alzheimer’s disease mouse model induced by intracerebroventricular injection of amyloid-β1-42 and human cerebral microvascular endothelial cells treated with amyloid-β1-42.In human cerebral microvascular endothelial cells,neutral sphingomyelinase 1 inhibitor interfered with the changes of sphingomyelin metabolism and P-glycoprotein expression and functionality caused by amyloid-β1-42 treatment.Neutral sphingomyelinase 1 regulated the expression and functionality of P-glycoprotein and the levels of sphingomyelin and ceramide.Together,these findings indicate that neutral sphingomyelinase 1 regulates the expression and function of P-glycoprotein via the sphingomyelin/ceramide pathway.These studies may serve as new pursuits for the development of anti-Alzheimer’s disease drugs.
文摘近些年,伴随着国家积极的推动新医疗改革措施落地,在此背景之下,按照患者疾病诊断相关分组(Diagnosis Related Groups,DRG)成为了新医改的重点内容。DRG这种支付结算方式使得现阶段国内的公立医院在资金以及运营管理压力方面显著增加,同时也为国内医院的经营以及管理工作带来了较大的挑战。为此,本文对DRG支付模式在公立医院的经营以及管理服务方面所产生的问题进行分析,并以此为基础,提出了几点针对性的改善策略,以期为行业人员提供参考。
基金Supported by State Key Laboratory of Urban Water Resource and Environment(2016DX01)the Fundamental Research Funds for the Central University(NSRIF.2014096)Science and Technology Planning Project of Chancheng District(2013A1044)
文摘A numerical model was established to predict and optimise the chemical cleaning process of Polyvinylidene Fluo- ride （PVDF） Ultrafiltration （UF） membranes with the results from the experiment that applied the Response Sur- face Method （RSM） and Central Composite Design （CCD）. The factors considered in the experimental design were sodium hydroxide （NaOH） concentration, sodium bypochlorite concentration （NaCIO）, citric acid concentration and cleaning duration, The interactions between the factors were investigated with the numerical model. Humic acid （20 mg· L-1） was used as the model foulant, and chemical enhanced backflush （CEB） was employed to sim- ulate the chemical cleaning process. The concentrations of sodium hydroxide, sodium hypochlorite, citric acid and cleaning duration tested during the experiments were in the range of 0.1%-0.3% 100-300 mg· L-1 1%-3% and 0.5-1.5 h, respectively. Among the variables, the sodium hypochlorite concentration and the cleaning dura- tion showed a positive relationship involving the increased efficiency of the chemical cleaning. The chemical cleaning efficiency was hardly improved with increasing concentrations of sodium hydroxide. However, the data was sharply decreased when at a low level of sodium hydroxide concentration. In total, 54 sets of cleaning schemes with 80% to 100K cleaning efficiency were observed with the R＆M model after calibration.
基金The authors acknowledge the financial support from the National Natural Science Foundation of China(51778170)State Key Laboratory of Urban Water Resource and Environment(2020DX04)+1 种基金Fundamental Research Funds for the Central Universities,China Postdoctoral Science Foundation(2019M651290)Heilongjiang Postdoctoral Science Foundation(LBH-Z19153).
文摘Ultrafiltration(UF)has been increasingly implemented in drinking water treatment plants;however,algae and their secretions can cause severe membrane fouling and pose great challenges to UF in practice.In this study,a simple and practical chemically enhanced backwashing(CEB)process was developed to address such issues using various cleaning reagents,including sodium hypochlorite(NaClO),sodium chloride(NaCl),sodium hydroxide(NaOH),sodium citrate,and their combinations.The results indicate that the type of chemical played a fundamental role in alleviating the hydraulically irreversible membrane fouling(HIMF),with NaClO as the best-performing reagent,followed by NaCl.Furthermore,a CEB process using a combination of NaClO with NaCl,NaOH,or sodium citrate delivered little improvement in the alleviation of membrane fouling compared with NaClO alone.The optimized dosage and dosing frequency of NaClO were 10 mg·L^(-1) two times per day.Long-term pilot-scale and full-scale experiments further verified the feasibility of the CEB process in relieving algae-derived membrane fouling.Compared with the conventional hydraulic backwashing without chemical involvement,the CEB process can effectively remove the organic foulants including biopolymers,humic substances,and proteinlike substances by means of oxidization,thereby weakening the cohesive forces between the organic foulants and the membrane surface.Therefore,the CEB process can efficiently alleviate the algae-related membrane fouling with lower chemical consumption,and is proposed as an alternative to control membrane fouling in treating the algae-containing surface water.
基金supported by the National Natural Science Foundation of China(U22A2024052300001)+2 种基金China Postdoctoral Science Foundation(2023M730275)State Key Laboratory of Urban Water Resource and Environment(Harbin Institute of Technology)(2022TS01)Fundamental Research Funds for the Central Universities。
文摘Water reuse is an effective way to solve the issues of current wastewater increments and water resource scarcity.Ultrafiltration,a promising method for water reuse,has the characteristics of low energy consumption,easy operation,and high adaptability to coupling with other water treatment processes.However,emerging organic contaminants(EOCs)in municipal wastewater cannot be effectively intercepted by ultrafiltration,which poses significant challenges to the effluent quality and sustainability of ultrafiltration process.Here,we develop a cobalt single-atom catalyst-tailored ceramic membrane(Co1-NCNT-CM)in conjunction with an activated peroxymonosulfate(PMS)system,achieving excellent EOCs degradation and anti-fouling performance.An interfacial reaction mechanism effectively mitigates membrane fouling through a repulsive interaction with natural organic matter.The generation of singlet oxygen at the Co-N3-C active sites through a catalytic pathway(PMS/PMS*/OH*/O*/OO*/1 O_(2))exhibits selective oxidation of phenols and sulfonamides,achieving>90%removal rates.Our findings elucidate a multi-layered functional architecture within the Co1-NCNT-CM/PMS system,responsible for its superior performance in organic decontamination and membrane maintenance during secondary effluent treatment.It highlights the power of integrating Co1-NCNT-CM/PMS systems in advanced wastewater treatment frameworks,specifically for targeted EOCs removal,heralding a new direction for sustainable water management.
基金co-supported by the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe National Natural Science Foundation of China (No. 11302105)
文摘Efficient and accurate strength analysis of bolted connections is essential in analyzing the integral thermal protection system（ITPS） of hypersonic vehicles, since the system bears severe loads and structural failures usually occur at the connections. Investigations of composite mechanical properties used in ITPS are still in progress as the architecture of the composites is complex. A new method is proposed in this paper for strength analysis of bolted connections by investigating the elastic behavior and failure strength of three-dimensional C/C orthogonal composites used in ITPS. In this method a multi-scale finite element method incorporating the global–local method is established to ensure high efficiency in macro-scale and precision in meso-scale in analysis.Simulation results reveal that predictions of material properties show reasonable accuracy compared with test results. And the multi-scale method can analyze the strength of connections efficiently and accurately.
基金This work was jointly supported by the National Natural Science Foundation of China(No.51608150)Open Project of State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(No.ES201810-02)+2 种基金Natural Science Foundation of Heilongjiang Province(No.E2017042)China Postdoctoral Science Foundation Grant(Nos.2018T110303 and 2017M610210)Heilongjiang Province Postdoctoral Science Foundation Grant(LBH-TZ14 and LBHZ16070).
文摘Energy uncoupling is often used for sludge reduction because it is easy to operate and does not require a significant amount of extra equipments(i.e.no additional tank required).However,over time the supernatant extracted using this method can deteriorate,ultimately requiring further treatment.The purpose of this study was to determine the effect of using a low-pressure ultrafiltration membrane process for sludge water recovery after the sludge had undergone an energy uncoupling treatment(using 3,3’,4’,5-tetrachlorosalicylanilide(TCS)).Energy uncoupling was found to break apart sludge floe by reducing extracellular polymeric substances(EPS)and adenosine triphosphate(ATP)content.Analysis of supernatant indicated that when energy uncoupling and membrane filtration were coapplied and the TCS dosage was below 30 mg/L,there was no significant deterioration in organic component removal.However,ammonia and phosphate concentrations were found to increase as the concentration of TCS added increased.Additionally,due to low sludge concentrations and EPS contents,addition of 30-60 mg/L TCS during sludge reduction increased the permeate flux(two times higher than the control)and decreased the hydraulic reversible and cake layer resistances.In contrast,high dosage of TCS aggravated membrane fouling by forming compact fouling layers.In general,this study found that the co-application of energy uncoupling and membrane filtration processes represents an effective alternative method for simultaneous sludge reduction and sludge supernatant recovery.
基金This work was jointly supported by the National Natural Science Foundation of China(Grant No.51608150)the Open Project of State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(No.ES201810-02)+3 种基金the Natural Science Foundation of Heilongjiang Province(No.E2017042)the Natural Science Foundation of Harbin(No.2017RAQXJ206)special support from the China Postdoctoral Fund(No.2018T110303)special support from the Heilongjiang Postdoctoral Found(No.LBH-TZ14).
文摘The gravity-driven membrane bioreactor(MBR)system is promising for decentralized sewage treatment because of its low energy consumption and maintenance requirements.However,the growing sludge not only increases membrane fouling,but also augments operational complexities(sludge discharge).We added the metabolic uncoupler 3,3’,4f,5-tetrachlorosalicylanilide(TC$)to the system to deal with the mentioned issues.Based on the results,TCS addition effectively decreased sludge ATP and sludge yield(reduced by 50%).Extracellular polymeric substances(EPS;proteins and polysaccharides)decreased with the addition of TCS and were transformed into dissolved soluble microbial products(SMPs)in the bulk solution,leading to the break of sludge floes into small fragments.Permeability was increased by more than two times,reaching 60-70 L/m2/h bar when 10-30 mg/L TCS were added,because of the reduced suspended sludge and the formation of a thin cake layer with low EPS levels.Resistance analyses confirmed that appropriate dosages of TCS primarily decreased the cake layer and hydraulically reversible resistances.Permeability decreased at high dosage(50 mg/L)due to the release of excess sludge fragments and SMP into the supernatant,with a thin but more compact fouling layer with low bioactivity developing on the membrane surface,causing higher cake layer and pore blocking resistances.Our study provides a fundamental understanding of how a metabolic uncoupler affects the sludge and bio-fouling layers at different dosages,with practical relevance for in situ sludge reduction and membrane fouling alleviation in MBR systems.
基金supported by the Important Project of Science and Technology for Water Pollution Control and Treatment (No:2009ZX07424-005-01)
文摘Drinking water treatment sludge,characterized as accumulated suspended solids and organic and inorganic matter,is produced in large quantities during the coagulation process.The proper disposal,regeneration or reuse of sludge is,therefore,a significant environmental issue.Reused sludge at low temperatures is an alternative method to enhance traditional coagulation efficiency.In the present study,the recycling mass of mixed sludge and properties of raw water （such as pH and turbidity） were systematically investigated to optimize coagulation efficiency.We determined that the appropriate dosage of mixed sludge was 60 mL/L,effective initial turbidity ranges were below 45.0 NTU,and optimal pH for DOMs and turbidity removal was 6.5-7.0 and 8.0,respectively.Furthermore,by comparing the flocs characteristics with and without recycling sludge,we found that floc structures with sludge were more irregular with average size growth to 64.7 μm from 48.1 μm.Recycling sludge was a feasible and successful method for enhancing pollutants removal,and the more irregular flocs structure after recycling might be caused by breakage of reused flocs and incorporation of powdered activated carbon into larger flocs structure.Applied during the coagulation process,recycling sludge could be significant for the treatment of low temperature and micro-polluted source water.
基金This work was supported by the National Key R&D Program of China(NO.2016YFC1303503)the Key Biomedical Program of Shanghai(NO.17431902200 and 18431902600)the Open Research Fund of State Key Laboratory of Genetic Engineering of Fudan University(NO.SKLGE1816).
文摘The discrepancy of indoleamine 2,3-dioxygenase 1(IDO1)function in atherosclerosis has been noted.Compared to the protective effect of IDO1 against established atherogenesis,the role of IDO1 in the developmental process of atherosclerosis is still unclear.Here,the expression patterns and activities of IDO1 and its isoenzyme tryptophan 2,3-dioxygenase(TDO)in aortas and blood samples of patients with atherosclerosis were investigated.IDO1 and TDO were colocalized with CD3-positive lymphocytes and CD68-positive macrophages in atherosclerotic lesions.The expression and activity of IDO1 and TDO increased with the grade of the histological classification in early atherosclerosis(grade I,II),but the increase did not continue in advanced atherosclerosis(grade III).Treatment of THP-1 macrophages(THP-M)with oxidized low-density lipoprotein(oxLDL)induced the expression of IDO1 via the PI3K/Akt/NF-κB pathway,indicating the potential function of IDO1 in foam cells.Before and after treatment with oxLDL on THP-M,IFN-γ-induced IDO1 exhibited different degrees of promotion on foaming,inflammatory factor production and cell apoptosis.Finally,we found that the IDO1 inhibitor 1-methyl-tryptophan could elevate the high-density lipoprotein cholesterol level in serum and reduce the area of the aortic atherosclerotic lesions in high-fat diet-fed ApoE−/−mice.Our study indicated that IDO1 played a complicated and unfixed role in the entire process of atherogenesis,despite the atheroprotective role in established atherosclerosis.IDO1 also had proatherosclerotic functions in the developmental stages of atherosclerosis.Modulation of IDO1 could be a good method for alleviating atherosclerosis.
基金supported by the National Natural Science Foundation of China (No. 51308146)the Program for New Century Excellent Talents in University (No. NCET-13-0169)+2 种基金the China Postdoctoral Science Foundation funded project (No. 2015T80360)the Heilongjiang Postdoctoral Fund (No. LBH-Z13083)the Open Project of State Key Laboratory of Urban Water Resource and Environment (No. ES201511-02)
文摘As a routine measurement to alleviate membrane fouling, hydraulic cleaning is of great significance for the steady operation of ultrafiltration（UF） systems in water treatment processes. In this work, a comparative study was performed to investigate the effects of the composition of backwash water on the hydraulic cleaning performance of UF membranes fouled by humic acid（HA）. Various types of backwash water, including UF permeate, Milli-Q water, Na Cl solution, CaCl_2 solution and HA solution, were compared in terms of hydraulically irreversible fouling index, total surface tension and residual HA. The results indicated that Milli-Q water backwash was superior to UF permeate backwash in cleaning HA-fouled membranes, and the backwash water containing Na＋or HA outperformed Milli-Q water in alleviating HA fouling. On the contrary, the presence of Ca^（2＋） in backwash water significantly decreased the backwash efficiency. Moreover, Ca^（2＋） played an important role in foulant removal, and the residual HA content closely related to the residual Ca^（2＋） content.Mechanism analysis suggested that the backwash process may involve fouling layer swelling, ion exchange, electric double layer release and competitive complexation. Ion exchange and competitive complexation played significant roles in the efficient hydraulic cleaning associated with Na＋and HA, respectively.
