In this study,a fouled ballast taken from the site of Sénissiat,France,was investigated.For the hydraulic behaviour,a large-scale cell was developed allowing drainage and evaporation tests to be carried out with ...In this study,a fouled ballast taken from the site of Sénissiat,France,was investigated.For the hydraulic behaviour,a large-scale cell was developed allowing drainage and evaporation tests to be carried out with monitoring of both suction and volumetric water content at various positions of the sample.It was observed that the hydraulic conductivity of fouled ballast is decreasing with suction increase,as for common unsaturated soils.The effect of fines content was found to be negligible.For the mechanical behaviour,both monotonic and cyclic triaxial tests were carried out using a large-scale triaxial cell.Various water contents were considered.The results were interpreted in terms of shear strength and permanent axial strain.It appeared that the water content is an important factor to be accounted for since any increase of water content or degree of saturation significantly decreases the shear strength and increases the permanent strain.Constitutive modelling has been attempted based on the experimental results.The model in its current state is capable of describing the effects of stress level,cycle number and water content.展开更多
Cleaning of hollow-fibre polyvinyl chloride （PVC） membrane with different chemical reagents after ultrafiltration of algal-rich water was investigated. Among the tested cleaning reagents （NaOH, HCl, EDTA, and NaClO...Cleaning of hollow-fibre polyvinyl chloride （PVC） membrane with different chemical reagents after ultrafiltration of algal-rich water was investigated. Among the tested cleaning reagents （NaOH, HCl, EDTA, and NaClO）, 100 mg/L NaClO exhibited the best performance （88.4% ± 1.1%） in removing the irreversible fouling resistance. This might be attributed to the fact that NaClO could eliminate almost all the major foulants such as carbohydrate-like and protein-like materials on the membrane surface, as confirmed by Fourier transform infrared spectroscopy analysis. However, negligible irreversible resistance （1.5% ± 1.0%） was obtained when the membrane was cleaning by 500 mg/L NaOH for 1.0 hr, although the NaOH solution could also desorb a portion of the major foulants from the fouled PVC membrane. Scanning electronic microscopy and atomic force microscopy analyses demonstrated that 500 mg/L NaOH could change the structure of the residual foulants on the membrane, making them more tightly attached to the membrane surface. This phenomenon might be responsible for the negligible membrane permeability restoration after NaOH cleaning. On the other hand, the microscopic analyses reflected that NaClO could effectively remove the foulants accumulated on the membrane surface.展开更多
The lateral resistance of sleeper plays an important role in ensuring the stability of a railway track, which may change in the operation of railway, due to the fouling in the ballast bed. In this work, discrete eleme...The lateral resistance of sleeper plays an important role in ensuring the stability of a railway track, which may change in the operation of railway, due to the fouling in the ballast bed. In this work, discrete element method was adopted to investigate the effect of fouling on the lateral resistance of sleeper. The shape information of ballast was captured by method of three-dimensional vision reconstruction. In order to calibrate the mechanical parameters and verify the models, a lateral resistance field test was carried out by using a custom-made device. The contact force distributions in the different parts of sleeper as well as the interaction between ballast and sleeper were discussed in depth. The results show that fouling of ballast bed evidently reduces the lateral resistance of sleeper and the decreasing degree is also related to the fouled position of ballast bed, in the order of shoulder > bottom > side.Therefore, the effect of fouling, especially the fouling in the ballast shoulder, on the lateral resistance of sleeper, should be taken into account in ballast track maintenance work.展开更多
Na Cl O has been widely used to restore membrane flux in practical membrane cleaning processes,which would induce the formation of toxic halogenated byproducts.In this study,we proposed a novel heatactivated peroxydis...Na Cl O has been widely used to restore membrane flux in practical membrane cleaning processes,which would induce the formation of toxic halogenated byproducts.In this study,we proposed a novel heatactivated peroxydisulfate(heat/PDS)process to clean the membrane fouling derived from humic acid(HA).The results show that the combination of heat and PDS can achieve almost 100%recovery of permeate flux after soaking the HA-fouled membrane in 1 mmol/L PDS solution at 50℃ for 2 h,which is attributed to the changes of HA structure and enhanced detachment of foulants from membranes.The properties of different treated membranes are characterized by scanning electron microscopy(SEM),atomic force microscope(AFM),attenuated total reflection Fourier transform infrared spectroscopy(ATRFTIR),and X-ray photoelectron spectroscopy(XPS),demonstrating that the reversible and irreversible foulants could be effectively removed by heat/PDS cleaning.The filtration process and fouling mechanism of the cleaned membrane were close to that of the virgin membrane,illustrating the good reusability of the cleaned membrane.Additionally,heat/PDS which can avoid the generation of halogenated byproducts shows comparable performance to Na Cl O on membrane cleaning and high performance for the removal of fouling caused by sodium alginate(SA),HA-bovine serum albumin(BSA)-SA mixture and algae,further suggesting that heat/PDS would be a potential alternative for membrane cleaning in practical application.展开更多
Membrane fouling is a persistent challenge in membrane-based technologies,significantly impacting efficiency,operational costs,and system lifespan in applications like water treatment,desalination,and industrial proce...Membrane fouling is a persistent challenge in membrane-based technologies,significantly impacting efficiency,operational costs,and system lifespan in applications like water treatment,desalination,and industrial processing.Foul-ing,caused by the accumulation of particulates,organic compounds,and microorganisms,leads to reduced permeability,increased energy demands,and frequent maintenance.Traditional fouling control approaches,relying on empirical models and reactive strategies,often fail to address these issues efficiently.In this context,artificial intelligence(AI)and machine learning(ML)have emerged as innovative tools offering predictive and proactive solutions for fouling man-agement.By utilizing historical and real-time data,AI/ML techniques such as artificial neural networks,support vector machines,and ensemble models enable accurate prediction of fouling onset,identification of fouling mechanisms,and optimization of control measures.This review provides a detailed examination of the integration of AI/ML in membrane fouling prediction and mitigation,discussing advanced algorithms,the role of sensor-based monitoring,and the importance of robust datasets in enhancing predictive accuracy.Case studies highlighting successful AI/ML applications across various membrane processes are presented,demonstrating their transformative potential in improving system performance.Emerging trends,such as hybrid modeling and IoT-enabled smart systems,are explored,alongside a criti-cal analysis of research gaps and opportunities.This review emphasizes AI/ML as a cornerstone for sustainable,cost-effective membrane operations.展开更多
Planktonic bacteria adhere and subsequently form biofilms on implantable medical devices can cause severe infections that have become the major types of hospital-acquired infections.Traditional coatings for the implan...Planktonic bacteria adhere and subsequently form biofilms on implantable medical devices can cause severe infections that have become the major types of hospital-acquired infections.Traditional coatings for the implants are frequently lack of long-term antifouling and bactericidal activities.It is still a big challenge to simultaneously improve the antifouling and bactericidal activities of the coatings.Herein,we report that mixed-charge glycopolypeptide coatings are of long-term antibacterial activities to efficiently inhibit the biofilm growth.The glycosylation of mixed-charge polypeptides has led to a significant improvement of both antifouling and bactericidal activities.The cooperative effect of the saccharide residues and mixed-charge residues improved the resistance of the polypeptide coatings against protein adsorption.The saccharide and L-glutamic acid(E)residues collectively enhanced the bacterial membrane-disruption of cationic L-lysine(K)residues,leading to potent bactericidal activity.Meanwhile,the glycopolypeptide coatings showed superior biocompatibility,long-term antibiofilm and anti-infection properties in two types of mouse subcutaneous infection models and one type of mouse urinary tract infection model.This work provides a new strategy to achieve antibacterial coatings with long-term activities for preventing implantable medical device associated infections.展开更多
As part of sewage treatment,coagulation could remove phosphorus from the effluent of the Anaerobic-Anoxic-Oxic-Anoxic(A^(2)OA)biological process.The importance in investigating the influence of coagulation on Anaerobi...As part of sewage treatment,coagulation could remove phosphorus from the effluent of the Anaerobic-Anoxic-Oxic-Anoxic(A^(2)OA)biological process.The importance in investigating the influence of coagulation on Anaerobic-Anoxic-Oxic-Anoxic Membrane Bioreactor(A^(2)OA-MBR)should be emphasized.In this study,systematic optimization of coagulation parameters for greater pollutant removal was conducted in terms of coagulant dosage,coagulation residence time and stirring hydraulic conditions.Coagulation process could remarkably remove turbidity,phosphorus,chemical oxygen demand,humic-like,protein-like and polysaccharide-like substances from secondary effluent and A^(2)OA sludge-liquid mixture.Furthermore,the influence of coagulation on membrane fouling development during the ultrafiltration of secondary effluent and A^(2)OA sludge-liquid mixture was investigated based on optimum coagulation parameters.Coagulation simultaneously reduced reversible membrane fouling and the irreversible one by 86%and 16%,respectively.According to excitation-emission matrix and attenuated total reflection-fourier transform infrared spectra,membrane fouling was primarily influenced by the cake layer,although pore fouling might be aggravated by A^(2)OA processes.Besides,the feasibility of coagulation-assisted A^(2)OA-MBRwas also assessed using hollowfibermembranes.It exhibited excellent potential in alleviatingmembrane fouling,while regular cleaning twice a day was not enough to suppress transmembrane pressure increase during direct domestic wastewater ultrafiltration.Additionally,both polysaccharide-like and protein-like foulants were vital components for membrane fouling during wastewater treatment.展开更多
Microbial fouling is an important challenge in water recovery system of manned spacecrafts for longer term missions.Microbial fouling of 5A06 aluminium alloy induced by typical extreme environment-resistant bacteria i...Microbial fouling is an important challenge in water recovery system of manned spacecrafts for longer term missions.Microbial fouling of 5A06 aluminium alloy induced by typical extreme environment-resistant bacteria in oligotrophic solutions of simulated condensate of manned spacecraft was investigated.Bacillus cereus showed poor survival ability to oligotrophic environments,and a small amount of remaining live B.cereus cells mainly existed in the form of spores without forming biofilms.And when B.cereus was mixed cultured with Cupriavidus metallidurans,the system was mainly affected by C.metallidurans biofilms rather than B.cereus cells.C.metallidurans could promote the thickness of passive films of aluminum alloy,so C.metallidurans posed a minor threat to the corrosion of 5A06 aluminum alloy.However,C.metallidurans showed strong adaptability to oligotrophic environments and formed a large number of biofilms.And the contamination threat of C.metallidurans still dominated even cultured with B.cereus.Even when cultured with B.cereus,the threat of contamination from C.metallidurans still pre-dominates.Therefore,C.metallidurans would pose a threat of microbial fouling to the oligotrophic water recovery system of manned spacecrafts.展开更多
The use of antifouling agents is suggested to be a promising method for protecting oceanic instruments from biological contamination.We developed a novel antifouling material doped with capsaicin(CAP)as a filler and m...The use of antifouling agents is suggested to be a promising method for protecting oceanic instruments from biological contamination.We developed a novel antifouling material doped with capsaicin(CAP)as a filler and montmorillonite(MMT)as a carrier for the practical application of CTD(conductivity,temperature,depth)protection.The optimal parameters for preparing the material were established,and the obtained material achieved the maximum CAP loading capacity of 32.74%.The proposed material exhibited great release properties in acidic environments,which is beneficial for reducing bacterial attachment.Furthermore,the optimal conditions(temperature,flow rate,and pressure in the aquatic environment)for a better release rate of the material were determined through a series of simulation tests in lab.It provided good guidance and basis for practical application of the material.The CAP@MMT composite showed excellent efficiency and effectiveness in preventing the attachment of microorganisms during the four-month marine field tests.In the subsequent experiments,the great properties of the antifouling material were further confirmed by retesting the conductivity of four instruments participating in marine field tests.The measuring errors of CTD protected by the antifouling material are both within 0.01 mS/cm,which is far lower than that of the other two instruments.展开更多
It is important to understand the evolution of the matter on the polymer membrane surface.The in situ and real-time monitoring of the membrane surface will not only favor the investigation of selective layer formation...It is important to understand the evolution of the matter on the polymer membrane surface.The in situ and real-time monitoring of the membrane surface will not only favor the investigation of selective layer formation but can also track the fouling process during operation.Herein,an aggregation-induced emission(AIE)-active polymer membrane was prepared by the interfacial polymerization of a cyclodextrin-based glycocluster(CD@Glucose)and a tetraphenylethylene derivative modified with boronic acid groups(TPEDB)on the surface of a polyacrylonitrile(PAN)ultrafiltration membrane.This interfacial polymerization method can be stacked layer-by-layer to regulate the hydrophilicity and pore structure of the membrane.With the increase in the number of polymer layers,the separation and antifouling properties of the membrane gradually improved.Owing to the AIE property of the crosslinking agent TPEDB,the occurrence of interfacial polymerization and the degree of fouling during membrane operation can be monitored by the fluorescence distribution and intensity.With the aggravation of membrane fouling,the fluorescence decreased gradually,but recovered after cleaning.Therefore,this AIE effect can be used for real-time monitoring of interfacial polymerization as well as membrane fouling.展开更多
Membrane filtration technology has been widely utilized for microalgae harvesting due to its stability and high efficiency.However,this technology faces challenges posed by membrane fouling caused by algal cells and e...Membrane filtration technology has been widely utilized for microalgae harvesting due to its stability and high efficiency.However,this technology faces challenges posed by membrane fouling caused by algal cells and extracellular organic matter(EOM),which are significantly influenced by membrane material and pore size.This study compared the fouling behavior of polyvinylidene fluoride(PVDF)membranes and ceramic membranes with similar pore sizes(0.20 mm and 0.16 mm,respectively)during the filtration of Microcystis aeruginosa.The ceramic membrane exhibited a lower transmembrane pressure(TMP)growth rate and reduced accumulation of surface foulants compared to the PVDF membrane,indicating its greater suitability for filtering algae-laden water.Further investigations employed membranes fabricated from aluminum oxide powders with grain sizes of 1 mm,3 mm,8 mm,and 10 mm,corresponding to membrane pore sizes of 0.08 mm,0.16 mm,0.66 mm,and 0.76 mm,respectively,to assess the impact of pore size on ceramic membrane fouling.The results revealed that increasing membrane pore size significantly lowered the TMP growth rate and reduced the irreversibility of membrane fouling.The extended DerjaguineLandaueVerweyeOverbeek(XDLVO)analysis indicated that large pore sizes enhanced repulsion between the ceramic membrane and algal foulants,further alleviating membrane fouling.This investigation offers new insights into optimizing membrane material and pore size for efficient filtration of algae-laden water.展开更多
Membrane fouling remains the primary economic barrier to the widespread implementation of membrane bioreactors (MBRs), despite the fact that they lead to the production of high-quality effluent. Operational conditions...Membrane fouling remains the primary economic barrier to the widespread implementation of membrane bioreactors (MBRs), despite the fact that they lead to the production of high-quality effluent. Operational conditions are critical factors influencing membrane fouling. This study aimed to investigate the simultaneous impacts of temperature and hydraulic retention time (HRT) variations on membrane fouling. Experiments were conducted at three different temperatures (18°C, 25°C, and 32°C) and HRTs (6 h, 9 h, and 15 h). The results demonstrated that increases in both temperature and HRT contributed to a reduction in membrane fouling. Additionally, a positive interaction between temperature and HRT was observed in the linear slope variation of membrane permeation, with temperature variations exerting a greater influence on membrane fouling than HRT variations. Fouling factor analysis revealed that increases in temperature and HRT led to decreased concentrations of soluble microbial products (SMP) and extracellular polymeric substances (EPS), particularly carbohydrates, in the activated sludge. Analyses of the cake layer of the membrane indicated that increasing temperature and HRT reduced EPS levels, particularly polysaccharides and proteins;altered primary protein structure;and increased the mean particle size distribution. Ultimately, these changes led to reductions in both reversible and irreversible hydraulic resistances. This study highlights the importance of optimizing operational parameters such as temperature and HRT to enhance membrane performance and treatment efficiency in MBR systems while mitigating fouling.展开更多
Concrete is subject to the synergistic effects of physical,chemical and biological processes throughout its life cycle.Among them,the corrosion of concrete by physical and chemical effects has been studied in detail.W...Concrete is subject to the synergistic effects of physical,chemical and biological processes throughout its life cycle.Among them,the corrosion of concrete by physical and chemical effects has been studied in detail.With the advance of various basic engineering facilities to the ocean,the deterioration mechanism of concrete caused by Marine fouling organisms remains to be studied.In particular,the corrosion and damage of Marine concrete by algae have rarely been reported by scholars.Therefore,combined with the current research status,we will review the mechanism of algal corrosion,the damage effect of algal adhesion on concrete and its interior,the factors affecting algal adhesion behavior,and the protection technology of algal adhesion.展开更多
Membrane fouling is the primary resistance to the continuous production of stirred membrane reactors.This work presents a laser-enhanced high-magnification telecentric imaging system(LEHTIS),which uses a high-magnific...Membrane fouling is the primary resistance to the continuous production of stirred membrane reactors.This work presents a laser-enhanced high-magnification telecentric imaging system(LEHTIS),which uses a high-magnification telecentric lens and laser-enhanced illumination to invasively capture the motion of particles on the membrane surface or near the membrane.The problems of working distance and particle interference in the stirred membrane reactor are solved to achieve the purpose of in-situ monitoring of membrane fouling.This method is suitable for high flow rates,high solid holdup,and small particle size systems,and the dynamic motion and accumulation of particles are preliminarily analyzed.It shows that the accumulation and desorption of particles on the membrane surface are related to the physical properties of the membrane surface.There is an intermittent rotational movement in the flow field near the membrane,and it tends to stabilize over time.The filtration process can be assessed by monitoring changes in the overall velocity and acceleration of particles near the membrane.The analysis of forces acting on individual particles is compared and validated with the force balance model to correct and accurately apply it to stirred membrane reactors.The development of LEHTIS provides an effective tool for in-situ monitoring of membrane fouling and optimizing the stirred membrane reactors for industrial applications.展开更多
The treatment of POME related contamination is complicated due to its high organic contents and complex composition.Membrane technology is a prominent method for removing POME contaminants on account of its efficiency...The treatment of POME related contamination is complicated due to its high organic contents and complex composition.Membrane technology is a prominent method for removing POME contaminants on account of its efficiency in removing suspended particles,organic substances,and contaminants from wastewater,leading to the production of high-quality treated effluent.It is crucial to achieve efficient POME treatment with minimum fouling through membrane advancement to ensure the sustainability for large-scale applications.This article comprehensively analyses the latest advancements in membrane technology for the treatment of POME.A wide range of membrane types including forward osmosis,microfiltration,ultrafiltration,nanofiltration,reverse osmosis,membrane bioreactor,photocatalytic membrane reactor,and their combinations is discussed in terms of the innovative design,treatment efficiencies and antifouling properties.The strategies for antifouling membranes such as self-healing and self-cleaning membranes are discussed.In addition to discussing the obstacles that impede the broad implementation of novel membrane tech nologies in POME treatment,the article concludes by delineating potential avenues for future research and policy considerations.The understanding and insights are expected to enhance the application ofmembrane-basedmethods in order to treat POME more efficiently;this will be instrumental in the reduction of environmental pollution.展开更多
Fouling caused by excess metal ions in hard water can negatively impact the performance of the circulating cooling water system(CCWS)by depositing ions on the heat exchanger's surface.Currently,the operation optim...Fouling caused by excess metal ions in hard water can negatively impact the performance of the circulating cooling water system(CCWS)by depositing ions on the heat exchanger's surface.Currently,the operation optimization of CCWS often prioritizes short-term flow velocity optimization for minimizing power consumption,without considering fouling.However,low flow velocity promotes fouling.Therefore,it's crucial to balance fouling and energy/water conservation for optimal CCWS long-term operation.This study proposes a mixed-integer nonlinear programming(MINLP)model to achieve this goal.The model considers fouling in the pipeline,dynamic concentration cycle,and variable frequency drive to optimize the synergy between heat transfer,pressure drop,and fouling.By optimizing the concentration cycle of the CCWS,water conservation and fouling control can be achieved.The model can obtain the optimal operating parameters for different operation intervals,including the number of pumps,frequency,and valve local resistance coefficient.Sensitivity experiments on cycle and environmental temperature reveal that as the cycle increases,the marginal benefits of energy/water conservation decrease.In periods with minimal impact on fouling rate,energy/water conservation can be achieved by increasing the cycle while maintaining a low fouling rate.Overall,the proposed model has significant energy/water saving effects and can comprehensively optimize the CCWS through its incorporation of fouling and cycle optimization.展开更多
The increasing demand for wastewater treatment has become a notable trend for addressing global water scarcity.However,fouling is a significant challenge for wastewater distribution engineering systems.This study prov...The increasing demand for wastewater treatment has become a notable trend for addressing global water scarcity.However,fouling is a significant challenge for wastewater distribution engineering systems.This study provides an approach using nanobubbles(NBs)to control fouling.The antifouling capacities of three types of NBs,six oxygen concentrations,and two application procedures(prevention and removal)are investigated.The results show that NBs effectively mitigate composite fouling—including biofouling,inorganic scaling,and particulate fouling—in comparison with the non-NBs group.More specifically,hydroxyl radicals generated by the self-collapse of NBs oxidize organics and kill microorganisms in wastewater.The negatively charged surfaces of the NBs transform the crystalline form of CaCO_(3)from calcite to looser aragonite,which reduces the likelihood of ion precipitation.Furthermore,the NBs gas-liquid interfaces act as gas"bridges"between colloidal particles,enhancing the removal of particles from wastewater.Lastly,although the NBs inhibit the growth of fouling,they do not significantly remove the already adhered fouling in non-NBs treated groups.This study anticipates that the application of NBs will address the significant fouling issue for various wastewater distribution engineering systems in order to meet the global challenge of sustainable water supplies.展开更多
Further treatment of secondary effluents before their discharge into the receiving water bodies could alleviate water eutrophication.In this study,the Chlorella proteinosa was cultured in a membrane photobioreactor to...Further treatment of secondary effluents before their discharge into the receiving water bodies could alleviate water eutrophication.In this study,the Chlorella proteinosa was cultured in a membrane photobioreactor to further remove nitrogen from the secondary effluents.The effect of hydraulic retention time(HRT)on microalgae biomass yields and nutrient removal was studied.The results showed that soluble algal products concentration reduced in the suspension at low HRT,thereby alleviating microalgal growth inhibition.In addition,the lower HRT reduced the nitrogen limitation for Chlorella proteinosa’s growth through the phase-out of nitrogen-related functional bacteria.As a result,the productivity for Chlorella proteinosa increased from 6.12 mg/L/day at an HRT of 24 hr to 20.18 mg/L/day at an HRT of 8 hr.The highest removal rates of 19.7 mg/L/day,23.8 mg/L/day,and 105.4 mg/L/day were achieved at an HRT of 8 hr for total nitrogen(TN),ammonia,and chemical oxygen demand(COD),respectively.However,in terms of removal rate,TN and COD were the largest when HRT is 24 hr,which were 74.5%and 82.6%respectively.The maximum removal rate of ammonia nitrogen was 99.2%when HRT was 8 hr.展开更多
Polyvinylidene fluoride(PVDF)polymer-based membranes are extensively used in wastewater treatment,yet their partially hydrophobic nature poses significant challenges.Numerous studies have focused on creating super-wet...Polyvinylidene fluoride(PVDF)polymer-based membranes are extensively used in wastewater treatment,yet their partially hydrophobic nature poses significant challenges.Numerous studies have focused on creating super-wetting membranes to enhance the water affinity of PVDF membranes.This review provides a comprehensive discussion on the hydrophilization of PVDF-based membranes,examining the chemical and physical properties that influence water affinity.Followed by various fabrication techniques,appropriate modifier materials,efficient operational conditions,and recent advancements in hydrophilization methods.Additionally,the review systematically evaluates the performance of these hydrophilized membranes in separating surfactant-stabilized oil-in-water emulsions,highlighting the importance of long-term stability and environmental considerations.The antifouling mechanisms and the effectiveness of hydrophilic membranes in oilewater separation processes are also discussed,offering insights into the development and application of these technologies.The discussion explain in this review provides important information for the research of wastewater treatment,green material and green industry.展开更多
In this study,a gravity-driven membrane(GDM)filtration system and hydroponic system(cultivating basil and lettuce)were combined for nutrient recovery from primary municipal wastewater.The GDM system was optimized by i...In this study,a gravity-driven membrane(GDM)filtration system and hydroponic system(cultivating basil and lettuce)were combined for nutrient recovery from primary municipal wastewater.The GDM system was optimized by increasing the periodic air sparging flow rate from 1 to 2 L/min(∼15 hr per 3-4 days),resulting in a∼52%reduction of irreversible fouling.However,the total fouling was not alleviated,and the water productivity remained comparable.The GDM-filtrated water was then delivered to hydroponic systems,and the effects of hydroponic operation conditions on plant growth and heavy metal uptake were evaluated,with fertilizer-and tap water-based hydroponic systems and soil cultivation sys-tem(with tap water)for comparison.It was found that(i)the hydroponic system under batchmode facilitated to promote vegetable growth with higher nutrient uptake rates com-pared to that under flow-through feed mode;(ii)a shift in nutrient levels in the hydroponic system could impact plant growth(such as plant height and leaf length),especially in the early stages.Nevertheless,the plants cultivated with the GDM-treated water had compara-ble growth profiles to those with commercial fertilizer or in soils.Furthermore,the targeted hazard quotient levels of all heavy metals for the plants in the hydroponic system with the treated water were greatly lower than those with the commercial fertilizer.Especially,com-pared to the lettuce,the basil had a lower heavy metal uptake capability and displayed a negligible impact on long-term human health risk,when the treated water was employed for the hydroponic system.展开更多
基金Project supported by the General Council of Ile-de-France and the Department of Seine-et-Marne,France
文摘In this study,a fouled ballast taken from the site of Sénissiat,France,was investigated.For the hydraulic behaviour,a large-scale cell was developed allowing drainage and evaporation tests to be carried out with monitoring of both suction and volumetric water content at various positions of the sample.It was observed that the hydraulic conductivity of fouled ballast is decreasing with suction increase,as for common unsaturated soils.The effect of fines content was found to be negligible.For the mechanical behaviour,both monotonic and cyclic triaxial tests were carried out using a large-scale triaxial cell.Various water contents were considered.The results were interpreted in terms of shear strength and permanent axial strain.It appeared that the water content is an important factor to be accounted for since any increase of water content or degree of saturation significantly decreases the shear strength and increases the permanent strain.Constitutive modelling has been attempted based on the experimental results.The model in its current state is capable of describing the effects of stress level,cycle number and water content.
基金supported by the Important Special Program of Science and Technology for the Control and Treatment of Water Pollution in China(No.2008ZX07422-005)the National Science and Technology Project of Eleventh Five Years(No.2006BAJ08B05-2)+2 种基金the National Creative Research Groups Foundation of China(No.50821002)the State Key Laboratory of Urban Water Resource and Environment(No.2008DX04)the National Postdoctoral Science Foundation of China(No.20100471062)
文摘Cleaning of hollow-fibre polyvinyl chloride （PVC） membrane with different chemical reagents after ultrafiltration of algal-rich water was investigated. Among the tested cleaning reagents （NaOH, HCl, EDTA, and NaClO）, 100 mg/L NaClO exhibited the best performance （88.4% ± 1.1%） in removing the irreversible fouling resistance. This might be attributed to the fact that NaClO could eliminate almost all the major foulants such as carbohydrate-like and protein-like materials on the membrane surface, as confirmed by Fourier transform infrared spectroscopy analysis. However, negligible irreversible resistance （1.5% ± 1.0%） was obtained when the membrane was cleaning by 500 mg/L NaOH for 1.0 hr, although the NaOH solution could also desorb a portion of the major foulants from the fouled PVC membrane. Scanning electronic microscopy and atomic force microscopy analyses demonstrated that 500 mg/L NaOH could change the structure of the residual foulants on the membrane, making them more tightly attached to the membrane surface. This phenomenon might be responsible for the negligible membrane permeability restoration after NaOH cleaning. On the other hand, the microscopic analyses reflected that NaClO could effectively remove the foulants accumulated on the membrane surface.
基金Projects(U1234211,61472029,51208034)supported by the National Natural Science Foundation of China
文摘The lateral resistance of sleeper plays an important role in ensuring the stability of a railway track, which may change in the operation of railway, due to the fouling in the ballast bed. In this work, discrete element method was adopted to investigate the effect of fouling on the lateral resistance of sleeper. The shape information of ballast was captured by method of three-dimensional vision reconstruction. In order to calibrate the mechanical parameters and verify the models, a lateral resistance field test was carried out by using a custom-made device. The contact force distributions in the different parts of sleeper as well as the interaction between ballast and sleeper were discussed in depth. The results show that fouling of ballast bed evidently reduces the lateral resistance of sleeper and the decreasing degree is also related to the fouled position of ballast bed, in the order of shoulder > bottom > side.Therefore, the effect of fouling, especially the fouling in the ballast shoulder, on the lateral resistance of sleeper, should be taken into account in ballast track maintenance work.
基金supported by the Natural Science Foundation of China(Nos.52070081,51578258 and 51878308)the National Key Research and Development Program of China(No.2022YFC3203500)。
文摘Na Cl O has been widely used to restore membrane flux in practical membrane cleaning processes,which would induce the formation of toxic halogenated byproducts.In this study,we proposed a novel heatactivated peroxydisulfate(heat/PDS)process to clean the membrane fouling derived from humic acid(HA).The results show that the combination of heat and PDS can achieve almost 100%recovery of permeate flux after soaking the HA-fouled membrane in 1 mmol/L PDS solution at 50℃ for 2 h,which is attributed to the changes of HA structure and enhanced detachment of foulants from membranes.The properties of different treated membranes are characterized by scanning electron microscopy(SEM),atomic force microscope(AFM),attenuated total reflection Fourier transform infrared spectroscopy(ATRFTIR),and X-ray photoelectron spectroscopy(XPS),demonstrating that the reversible and irreversible foulants could be effectively removed by heat/PDS cleaning.The filtration process and fouling mechanism of the cleaned membrane were close to that of the virgin membrane,illustrating the good reusability of the cleaned membrane.Additionally,heat/PDS which can avoid the generation of halogenated byproducts shows comparable performance to Na Cl O on membrane cleaning and high performance for the removal of fouling caused by sodium alginate(SA),HA-bovine serum albumin(BSA)-SA mixture and algae,further suggesting that heat/PDS would be a potential alternative for membrane cleaning in practical application.
文摘Membrane fouling is a persistent challenge in membrane-based technologies,significantly impacting efficiency,operational costs,and system lifespan in applications like water treatment,desalination,and industrial processing.Foul-ing,caused by the accumulation of particulates,organic compounds,and microorganisms,leads to reduced permeability,increased energy demands,and frequent maintenance.Traditional fouling control approaches,relying on empirical models and reactive strategies,often fail to address these issues efficiently.In this context,artificial intelligence(AI)and machine learning(ML)have emerged as innovative tools offering predictive and proactive solutions for fouling man-agement.By utilizing historical and real-time data,AI/ML techniques such as artificial neural networks,support vector machines,and ensemble models enable accurate prediction of fouling onset,identification of fouling mechanisms,and optimization of control measures.This review provides a detailed examination of the integration of AI/ML in membrane fouling prediction and mitigation,discussing advanced algorithms,the role of sensor-based monitoring,and the importance of robust datasets in enhancing predictive accuracy.Case studies highlighting successful AI/ML applications across various membrane processes are presented,demonstrating their transformative potential in improving system performance.Emerging trends,such as hybrid modeling and IoT-enabled smart systems,are explored,alongside a criti-cal analysis of research gaps and opportunities.This review emphasizes AI/ML as a cornerstone for sustainable,cost-effective membrane operations.
基金the financial support from the National Natural Science Foundation of China(No.51873213)Science and Technology Program of Suzhou(No.SKY2022111)Collaborative Innovation Center of Suzhou Nano Science&Technology,and FUNSOM Self-Directed Research Project(No.2022)。
文摘Planktonic bacteria adhere and subsequently form biofilms on implantable medical devices can cause severe infections that have become the major types of hospital-acquired infections.Traditional coatings for the implants are frequently lack of long-term antifouling and bactericidal activities.It is still a big challenge to simultaneously improve the antifouling and bactericidal activities of the coatings.Herein,we report that mixed-charge glycopolypeptide coatings are of long-term antibacterial activities to efficiently inhibit the biofilm growth.The glycosylation of mixed-charge polypeptides has led to a significant improvement of both antifouling and bactericidal activities.The cooperative effect of the saccharide residues and mixed-charge residues improved the resistance of the polypeptide coatings against protein adsorption.The saccharide and L-glutamic acid(E)residues collectively enhanced the bacterial membrane-disruption of cationic L-lysine(K)residues,leading to potent bactericidal activity.Meanwhile,the glycopolypeptide coatings showed superior biocompatibility,long-term antibiofilm and anti-infection properties in two types of mouse subcutaneous infection models and one type of mouse urinary tract infection model.This work provides a new strategy to achieve antibacterial coatings with long-term activities for preventing implantable medical device associated infections.
基金supported by the National Natural Science Foundation of China(Nos.52170070,52400022 and 52200088)the Youth S&T Talent Support Programme of Guangdong Provincial Association for Science and Technology(GDSTA)(No.SKXRC202406)+1 种基金China Postdoctoral Science Foundation(No.2023M740754)“One hundred Youth”Science and Technology Plan,Guangdong University of Technology,China(No.263113906).
文摘As part of sewage treatment,coagulation could remove phosphorus from the effluent of the Anaerobic-Anoxic-Oxic-Anoxic(A^(2)OA)biological process.The importance in investigating the influence of coagulation on Anaerobic-Anoxic-Oxic-Anoxic Membrane Bioreactor(A^(2)OA-MBR)should be emphasized.In this study,systematic optimization of coagulation parameters for greater pollutant removal was conducted in terms of coagulant dosage,coagulation residence time and stirring hydraulic conditions.Coagulation process could remarkably remove turbidity,phosphorus,chemical oxygen demand,humic-like,protein-like and polysaccharide-like substances from secondary effluent and A^(2)OA sludge-liquid mixture.Furthermore,the influence of coagulation on membrane fouling development during the ultrafiltration of secondary effluent and A^(2)OA sludge-liquid mixture was investigated based on optimum coagulation parameters.Coagulation simultaneously reduced reversible membrane fouling and the irreversible one by 86%and 16%,respectively.According to excitation-emission matrix and attenuated total reflection-fourier transform infrared spectra,membrane fouling was primarily influenced by the cake layer,although pore fouling might be aggravated by A^(2)OA processes.Besides,the feasibility of coagulation-assisted A^(2)OA-MBRwas also assessed using hollowfibermembranes.It exhibited excellent potential in alleviatingmembrane fouling,while regular cleaning twice a day was not enough to suppress transmembrane pressure increase during direct domestic wastewater ultrafiltration.Additionally,both polysaccharide-like and protein-like foulants were vital components for membrane fouling during wastewater treatment.
基金supported by the National Natural Science Foundation of China(Nos.51971032,52371048,and 52071019).
文摘Microbial fouling is an important challenge in water recovery system of manned spacecrafts for longer term missions.Microbial fouling of 5A06 aluminium alloy induced by typical extreme environment-resistant bacteria in oligotrophic solutions of simulated condensate of manned spacecraft was investigated.Bacillus cereus showed poor survival ability to oligotrophic environments,and a small amount of remaining live B.cereus cells mainly existed in the form of spores without forming biofilms.And when B.cereus was mixed cultured with Cupriavidus metallidurans,the system was mainly affected by C.metallidurans biofilms rather than B.cereus cells.C.metallidurans could promote the thickness of passive films of aluminum alloy,so C.metallidurans posed a minor threat to the corrosion of 5A06 aluminum alloy.However,C.metallidurans showed strong adaptability to oligotrophic environments and formed a large number of biofilms.And the contamination threat of C.metallidurans still dominated even cultured with B.cereus.Even when cultured with B.cereus,the threat of contamination from C.metallidurans still pre-dominates.Therefore,C.metallidurans would pose a threat of microbial fouling to the oligotrophic water recovery system of manned spacecrafts.
基金supported by the directional Foundation of the Key Laboratory of Ocean Observation Technology,MNR(No.2021KlootB06)the National Natural Science Foundation of China(No.52271341)。
文摘The use of antifouling agents is suggested to be a promising method for protecting oceanic instruments from biological contamination.We developed a novel antifouling material doped with capsaicin(CAP)as a filler and montmorillonite(MMT)as a carrier for the practical application of CTD(conductivity,temperature,depth)protection.The optimal parameters for preparing the material were established,and the obtained material achieved the maximum CAP loading capacity of 32.74%.The proposed material exhibited great release properties in acidic environments,which is beneficial for reducing bacterial attachment.Furthermore,the optimal conditions(temperature,flow rate,and pressure in the aquatic environment)for a better release rate of the material were determined through a series of simulation tests in lab.It provided good guidance and basis for practical application of the material.The CAP@MMT composite showed excellent efficiency and effectiveness in preventing the attachment of microorganisms during the four-month marine field tests.In the subsequent experiments,the great properties of the antifouling material were further confirmed by retesting the conductivity of four instruments participating in marine field tests.The measuring errors of CTD protected by the antifouling material are both within 0.01 mS/cm,which is far lower than that of the other two instruments.
基金supported by the Fundamental Research Funds for Central Universities(No.30922010811).
文摘It is important to understand the evolution of the matter on the polymer membrane surface.The in situ and real-time monitoring of the membrane surface will not only favor the investigation of selective layer formation but can also track the fouling process during operation.Herein,an aggregation-induced emission(AIE)-active polymer membrane was prepared by the interfacial polymerization of a cyclodextrin-based glycocluster(CD@Glucose)and a tetraphenylethylene derivative modified with boronic acid groups(TPEDB)on the surface of a polyacrylonitrile(PAN)ultrafiltration membrane.This interfacial polymerization method can be stacked layer-by-layer to regulate the hydrophilicity and pore structure of the membrane.With the increase in the number of polymer layers,the separation and antifouling properties of the membrane gradually improved.Owing to the AIE property of the crosslinking agent TPEDB,the occurrence of interfacial polymerization and the degree of fouling during membrane operation can be monitored by the fluorescence distribution and intensity.With the aggravation of membrane fouling,the fluorescence decreased gradually,but recovered after cleaning.Therefore,this AIE effect can be used for real-time monitoring of interfacial polymerization as well as membrane fouling.
基金supported by the National Natural Science Foundation of China(Grant No.52370035)the Natural Science Foundation of Hebei Province,China(Grant No.E2023202064)the China Postdoctoral Science Foundation(Grant No.2024M750717).
文摘Membrane filtration technology has been widely utilized for microalgae harvesting due to its stability and high efficiency.However,this technology faces challenges posed by membrane fouling caused by algal cells and extracellular organic matter(EOM),which are significantly influenced by membrane material and pore size.This study compared the fouling behavior of polyvinylidene fluoride(PVDF)membranes and ceramic membranes with similar pore sizes(0.20 mm and 0.16 mm,respectively)during the filtration of Microcystis aeruginosa.The ceramic membrane exhibited a lower transmembrane pressure(TMP)growth rate and reduced accumulation of surface foulants compared to the PVDF membrane,indicating its greater suitability for filtering algae-laden water.Further investigations employed membranes fabricated from aluminum oxide powders with grain sizes of 1 mm,3 mm,8 mm,and 10 mm,corresponding to membrane pore sizes of 0.08 mm,0.16 mm,0.66 mm,and 0.76 mm,respectively,to assess the impact of pore size on ceramic membrane fouling.The results revealed that increasing membrane pore size significantly lowered the TMP growth rate and reduced the irreversibility of membrane fouling.The extended DerjaguineLandaueVerweyeOverbeek(XDLVO)analysis indicated that large pore sizes enhanced repulsion between the ceramic membrane and algal foulants,further alleviating membrane fouling.This investigation offers new insights into optimizing membrane material and pore size for efficient filtration of algae-laden water.
文摘Membrane fouling remains the primary economic barrier to the widespread implementation of membrane bioreactors (MBRs), despite the fact that they lead to the production of high-quality effluent. Operational conditions are critical factors influencing membrane fouling. This study aimed to investigate the simultaneous impacts of temperature and hydraulic retention time (HRT) variations on membrane fouling. Experiments were conducted at three different temperatures (18°C, 25°C, and 32°C) and HRTs (6 h, 9 h, and 15 h). The results demonstrated that increases in both temperature and HRT contributed to a reduction in membrane fouling. Additionally, a positive interaction between temperature and HRT was observed in the linear slope variation of membrane permeation, with temperature variations exerting a greater influence on membrane fouling than HRT variations. Fouling factor analysis revealed that increases in temperature and HRT led to decreased concentrations of soluble microbial products (SMP) and extracellular polymeric substances (EPS), particularly carbohydrates, in the activated sludge. Analyses of the cake layer of the membrane indicated that increasing temperature and HRT reduced EPS levels, particularly polysaccharides and proteins;altered primary protein structure;and increased the mean particle size distribution. Ultimately, these changes led to reductions in both reversible and irreversible hydraulic resistances. This study highlights the importance of optimizing operational parameters such as temperature and HRT to enhance membrane performance and treatment efficiency in MBR systems while mitigating fouling.
基金Funded by the National Natural Science Foundation of China(Nos.52278269,52278268,and 52178264)the Tianjin Outstanding Young Scholars Science Fund Project(No.22JCJQJC00020)+1 种基金the Key Project of Tianjin Natural Science Foundation(No.23JCZDJC00430)the Joint Research Center of China and Foreign Countries Special Fund of Tianjin Innovation Platform(No.24PTLYHZ00240)。
文摘Concrete is subject to the synergistic effects of physical,chemical and biological processes throughout its life cycle.Among them,the corrosion of concrete by physical and chemical effects has been studied in detail.With the advance of various basic engineering facilities to the ocean,the deterioration mechanism of concrete caused by Marine fouling organisms remains to be studied.In particular,the corrosion and damage of Marine concrete by algae have rarely been reported by scholars.Therefore,combined with the current research status,we will review the mechanism of algal corrosion,the damage effect of algal adhesion on concrete and its interior,the factors affecting algal adhesion behavior,and the protection technology of algal adhesion.
基金Financial support from the National Key Research and Development Program(2022YFB3504000)the National Natural Science Foundation of China(22421003,22478391,22178345)the Youth Innovation Promotion Association CAS(Y2023012,2022045,2023052)。
文摘Membrane fouling is the primary resistance to the continuous production of stirred membrane reactors.This work presents a laser-enhanced high-magnification telecentric imaging system(LEHTIS),which uses a high-magnification telecentric lens and laser-enhanced illumination to invasively capture the motion of particles on the membrane surface or near the membrane.The problems of working distance and particle interference in the stirred membrane reactor are solved to achieve the purpose of in-situ monitoring of membrane fouling.This method is suitable for high flow rates,high solid holdup,and small particle size systems,and the dynamic motion and accumulation of particles are preliminarily analyzed.It shows that the accumulation and desorption of particles on the membrane surface are related to the physical properties of the membrane surface.There is an intermittent rotational movement in the flow field near the membrane,and it tends to stabilize over time.The filtration process can be assessed by monitoring changes in the overall velocity and acceleration of particles near the membrane.The analysis of forces acting on individual particles is compared and validated with the force balance model to correct and accurately apply it to stirred membrane reactors.The development of LEHTIS provides an effective tool for in-situ monitoring of membrane fouling and optimizing the stirred membrane reactors for industrial applications.
基金financial support from SATREPS project(vote number:R.J130000.7801.4L977)KPM-UTM Grant(vote number:R.J130000.7301.4L997).
文摘The treatment of POME related contamination is complicated due to its high organic contents and complex composition.Membrane technology is a prominent method for removing POME contaminants on account of its efficiency in removing suspended particles,organic substances,and contaminants from wastewater,leading to the production of high-quality treated effluent.It is crucial to achieve efficient POME treatment with minimum fouling through membrane advancement to ensure the sustainability for large-scale applications.This article comprehensively analyses the latest advancements in membrane technology for the treatment of POME.A wide range of membrane types including forward osmosis,microfiltration,ultrafiltration,nanofiltration,reverse osmosis,membrane bioreactor,photocatalytic membrane reactor,and their combinations is discussed in terms of the innovative design,treatment efficiencies and antifouling properties.The strategies for antifouling membranes such as self-healing and self-cleaning membranes are discussed.In addition to discussing the obstacles that impede the broad implementation of novel membrane tech nologies in POME treatment,the article concludes by delineating potential avenues for future research and policy considerations.The understanding and insights are expected to enhance the application ofmembrane-basedmethods in order to treat POME more efficiently;this will be instrumental in the reduction of environmental pollution.
基金Financial support from the National Natural Science Foundation of China (22022816 and 22078358)
文摘Fouling caused by excess metal ions in hard water can negatively impact the performance of the circulating cooling water system(CCWS)by depositing ions on the heat exchanger's surface.Currently,the operation optimization of CCWS often prioritizes short-term flow velocity optimization for minimizing power consumption,without considering fouling.However,low flow velocity promotes fouling.Therefore,it's crucial to balance fouling and energy/water conservation for optimal CCWS long-term operation.This study proposes a mixed-integer nonlinear programming(MINLP)model to achieve this goal.The model considers fouling in the pipeline,dynamic concentration cycle,and variable frequency drive to optimize the synergy between heat transfer,pressure drop,and fouling.By optimizing the concentration cycle of the CCWS,water conservation and fouling control can be achieved.The model can obtain the optimal operating parameters for different operation intervals,including the number of pumps,frequency,and valve local resistance coefficient.Sensitivity experiments on cycle and environmental temperature reveal that as the cycle increases,the marginal benefits of energy/water conservation decrease.In periods with minimal impact on fouling rate,energy/water conservation can be achieved by increasing the cycle while maintaining a low fouling rate.Overall,the proposed model has significant energy/water saving effects and can comprehensively optimize the CCWS through its incorporation of fouling and cycle optimization.
基金support for this research was provided by the National Natural Science Foundation of China(52339004 and 52209074)Natural Science Foundation of Shandong Province(ZR2022QE079),National Key Research and Development Plan(2021YFD1900900)+3 种基金the earmarked fund for CARS-03,and the China Post-doctoral Science Foundation(BX2021363 and 2022M713394)Sunny C.Jiang was supported by US National Science Foundation(CBET 2027306,CBET 2128480,and CBET 1806066)US Bureau of Reclamation(R21AC10079-00)US Environmental Protection Agency(EPA-G2021-STAR-A1 and 84025701).
文摘The increasing demand for wastewater treatment has become a notable trend for addressing global water scarcity.However,fouling is a significant challenge for wastewater distribution engineering systems.This study provides an approach using nanobubbles(NBs)to control fouling.The antifouling capacities of three types of NBs,six oxygen concentrations,and two application procedures(prevention and removal)are investigated.The results show that NBs effectively mitigate composite fouling—including biofouling,inorganic scaling,and particulate fouling—in comparison with the non-NBs group.More specifically,hydroxyl radicals generated by the self-collapse of NBs oxidize organics and kill microorganisms in wastewater.The negatively charged surfaces of the NBs transform the crystalline form of CaCO_(3)from calcite to looser aragonite,which reduces the likelihood of ion precipitation.Furthermore,the NBs gas-liquid interfaces act as gas"bridges"between colloidal particles,enhancing the removal of particles from wastewater.Lastly,although the NBs inhibit the growth of fouling,they do not significantly remove the already adhered fouling in non-NBs treated groups.This study anticipates that the application of NBs will address the significant fouling issue for various wastewater distribution engineering systems in order to meet the global challenge of sustainable water supplies.
基金supported by the China Hunan Provincial Science&Technology Department(Nos.2022SK2091 and 2019JJ50646)the Hunan Provincial Department of Education(Nos.18C0206 and 19B040).
文摘Further treatment of secondary effluents before their discharge into the receiving water bodies could alleviate water eutrophication.In this study,the Chlorella proteinosa was cultured in a membrane photobioreactor to further remove nitrogen from the secondary effluents.The effect of hydraulic retention time(HRT)on microalgae biomass yields and nutrient removal was studied.The results showed that soluble algal products concentration reduced in the suspension at low HRT,thereby alleviating microalgal growth inhibition.In addition,the lower HRT reduced the nitrogen limitation for Chlorella proteinosa’s growth through the phase-out of nitrogen-related functional bacteria.As a result,the productivity for Chlorella proteinosa increased from 6.12 mg/L/day at an HRT of 24 hr to 20.18 mg/L/day at an HRT of 8 hr.The highest removal rates of 19.7 mg/L/day,23.8 mg/L/day,and 105.4 mg/L/day were achieved at an HRT of 8 hr for total nitrogen(TN),ammonia,and chemical oxygen demand(COD),respectively.However,in terms of removal rate,TN and COD were the largest when HRT is 24 hr,which were 74.5%and 82.6%respectively.The maximum removal rate of ammonia nitrogen was 99.2%when HRT was 8 hr.
基金supported by the World Class research Undip(WCRU)Program(Category A)from Diponegoro University(118-30/UN7.6.1/PP/2021).
文摘Polyvinylidene fluoride(PVDF)polymer-based membranes are extensively used in wastewater treatment,yet their partially hydrophobic nature poses significant challenges.Numerous studies have focused on creating super-wetting membranes to enhance the water affinity of PVDF membranes.This review provides a comprehensive discussion on the hydrophilization of PVDF-based membranes,examining the chemical and physical properties that influence water affinity.Followed by various fabrication techniques,appropriate modifier materials,efficient operational conditions,and recent advancements in hydrophilization methods.Additionally,the review systematically evaluates the performance of these hydrophilized membranes in separating surfactant-stabilized oil-in-water emulsions,highlighting the importance of long-term stability and environmental considerations.The antifouling mechanisms and the effectiveness of hydrophilic membranes in oilewater separation processes are also discussed,offering insights into the development and application of these technologies.The discussion explain in this review provides important information for the research of wastewater treatment,green material and green industry.
文摘In this study,a gravity-driven membrane(GDM)filtration system and hydroponic system(cultivating basil and lettuce)were combined for nutrient recovery from primary municipal wastewater.The GDM system was optimized by increasing the periodic air sparging flow rate from 1 to 2 L/min(∼15 hr per 3-4 days),resulting in a∼52%reduction of irreversible fouling.However,the total fouling was not alleviated,and the water productivity remained comparable.The GDM-filtrated water was then delivered to hydroponic systems,and the effects of hydroponic operation conditions on plant growth and heavy metal uptake were evaluated,with fertilizer-and tap water-based hydroponic systems and soil cultivation sys-tem(with tap water)for comparison.It was found that(i)the hydroponic system under batchmode facilitated to promote vegetable growth with higher nutrient uptake rates com-pared to that under flow-through feed mode;(ii)a shift in nutrient levels in the hydroponic system could impact plant growth(such as plant height and leaf length),especially in the early stages.Nevertheless,the plants cultivated with the GDM-treated water had compara-ble growth profiles to those with commercial fertilizer or in soils.Furthermore,the targeted hazard quotient levels of all heavy metals for the plants in the hydroponic system with the treated water were greatly lower than those with the commercial fertilizer.Especially,com-pared to the lettuce,the basil had a lower heavy metal uptake capability and displayed a negligible impact on long-term human health risk,when the treated water was employed for the hydroponic system.
