The increasing population and continuous urbanization make food security a key consideration in sustainable development.Efficient farming strategies with low environmental footprints are thus increasingly required to ...The increasing population and continuous urbanization make food security a key consideration in sustainable development.Efficient farming strategies with low environmental footprints are thus increasingly required to meet food demands.This study presents a design for environmentally friendly,economical,and modular vertical farming systems,in which vegetables are cultivated in a carbon dioxide(CO_(2))-enriched atmosphere enabled by direct air capture(DAC)and subjected to artificial light exposure.We established a vertical farming setup and conducted experiments to identify productive cultivation strategies by regulating lighting,CO_(2)concentration,biochar application,and plant species.Additionally,a self-developed DAC rotary adsorber was utilized to achieve stable and efficient CO_(2)enrichment.Compared with the control group,the fresh weight of the vegetables in the experimental groups increased by up to 57.5%.Furthermore,we performed a comprehensive evaluation of the design and demonstrated that integrating photovoltaic-thermal(PVT)and DAC units increased the system’s net present value(NPV)by 157%compared with a conventional design without these units.Importantly,we found it possible to maintain the low carbon footprint of the system(0.468 kg-CO_(2)equivalent·kg−1(CO_(2)eq·kg−1)-vegetable)in the production process.Parametric studies and an application analysis on a global scale reveal the wide adaptability of this strategy to diverse conditions.These findings,together with the modular characteristics of vertical farming systems,highlight the promising potential of this design to increase food security and foster sustainable agriculture.展开更多
Inspired by the remarkable surface wetting behavior of natural organisms,artificially designed superwettable systems have attracted significant attention from multidisciplinary scientists over the past two decades.Sta...Inspired by the remarkable surface wetting behavior of natural organisms,artificially designed superwettable systems have attracted significant attention from multidisciplinary scientists over the past two decades.Starch is an eco-friendly,nontoxic,and low-cost natural polymer that serves as an alternative to nonbiodegradable and/or bioincompatible synthetic polymers in these systems.This review explores the unique contributions of starch to superwettable systems from design principles to emerging applications.First,the fundamental theories and design principles underlying starch-involved superwettable systems are introduced.The specific design principles of these systems are comprehensively discussed from the aspects of intrinsic properties(e.g.,hydrophilicity,film-forming properties,adhesiveness,and thermal decomposition),dimensionality(e.g.,colloidal systems,zero-dimensional granules/particles,one-dimensional fibers,two-dimensional films/fibrous membranes/coatings,and three-dimensional fillers/porous materials/food textures),and biotransformation.It also provides an overview of their applications in functio nal biomaterials,oral delivery systems,emulsion polymerizatio n,packaging technology,food taste modulation,and water treatment,with particular emphasis on intelligent systems.Each section summarizes recent advancements,highlighting the chemical and structural features.Finally,the review considers prospects for these superwettable systems,focusing on underutilized starch attributes and technical challenges.展开更多
The rapid construction of artificial reservoirs in metropolises has promoted the emergence of city-river-reservoir systems worldwide.This study investigated the environmental behaviors and risks of heavy metals in the...The rapid construction of artificial reservoirs in metropolises has promoted the emergence of city-river-reservoir systems worldwide.This study investigated the environmental behaviors and risks of heavy metals in the aquatic environment of a typical system composed of main watersheds in Suzhou and Jinze Reservoir in Shanghai.Results shown that Mn,Zn and Cu were the dominant metals detected in multiple phases.Cd,Mn and Zn were mainly presented in exchangeable fraction and exhibited high bioavailability.Great proportion and high mobility of metals were found in suspended particulate matter(SPM),suggesting that SPM can greatly affect metal multi-phase distribution process.Spatially,city system(Ci S)exhibited more serious metal pollution and higher ecological risk than river system(Ri S)and reservoir system(Re S)owing to the diverse emission sources.Ci S and Re S were regarded as critical pollution source and sink,respectively,while Ri S was a vital transportation aisle.Microbial community in sediments exhibited evident spatial variation and obviously modified by exchangeable metals and nutrients.In particular,Bacteroidetes and Firmicutes presented significant positive correlations with most exchangeable metals.Risk assessment implied that As,Sb and Ni in water may pose potential carcinogenic risk to human health.Nevertheless,Re S was in a fairly safe state.Hg was the main risk contributor in SPM,while Cu,Zn,Ni and Sb showed moderate risk in sediments.Overall,Hg,Sb and Ci S were screened out as priority metals and system,respectively.More attention should be paid to these priority issues to promote the sustainable development of the watershed.展开更多
With increasing emission of silver nanoparticles(AgNPs) into the environment, it is important to understand the effects of ambient concentration of AgNPs. The biological effects of AgNPs on Scenedesmus obliquus, a ubi...With increasing emission of silver nanoparticles(AgNPs) into the environment, it is important to understand the effects of ambient concentration of AgNPs. The biological effects of AgNPs on Scenedesmus obliquus, a ubiquitous freshwater microalgae, was evaluated. AgNPs exerted a minor inhibitory effect at low doses. Non-targeted metabolomic studies were conducted to understand and analyze the effect of AgNPs on algal cells from a molecular perspective. During the 48 hr of exposure to AgNPs, 30 metabolites were identified, of which nine had significant changes compared to the control group. These include D-galactose, sucrose, and D-fructose.These carbohydrates are involved in the synthesis and repair of cell walls. Glycine, an important constituent amino acid of glutathione, increased with AgNP exposure concentration increasing, likely to counteract an increased intracellular oxidative stress. These results provide a new understanding of the toxicity effects and mechanism of AgNPs. These metabolites could be useful biomarkers for future research, employed in the early detection of environmental risk from AgNPs.展开更多
The flow dynamics of binary particle mixtures in the fluidized bed needs to be monitored in order to optimize the related industrial processes.In this paper,electrostatic sensing and high-speed imaging are applied to ...The flow dynamics of binary particle mixtures in the fluidized bed needs to be monitored in order to optimize the related industrial processes.In this paper,electrostatic sensing and high-speed imaging are applied to measure the velocities of polyethylene and sand particles in the binary particle mixtures in fluidization.Experimental studies were conducted on a lab-scale cold circulating fluidized bed.Correlation function between electrostatic signals from upstream and downstream electrodes placed along the riser shows two peaks that represent transit times for the two types of particles.To verify the above results,high-speed imaging was adopted to capture the flow images of particle mixtures.Particle Image Velocimetry and Particle Tracking Velocimetry algorithms were utilized to process the resulted images in order to measure the velocities of polyethylene and sand particles.The reasons for two-peak correlation functions are illustrated based on the frequency spectrums of the mono-solid-phase electrostatic signals and the velocity difference between polyethylene and sand particles.Finally,comparisons on the velocities obtained from electrostatic sensing and high-speed imaging demonstrate the electrostatic sensor can roughly estimate the particle velocity of binary particle mixtures in the near wall region of the circulating fluidized bed.展开更多
To realize full energy recovery from grass and chicken manure(CM), the integration of high-solid anaerobic digestion(HSAD) and gasification was investigated experimentally. The anaerobic biodegradability of grass can ...To realize full energy recovery from grass and chicken manure(CM), the integration of high-solid anaerobic digestion(HSAD) and gasification was investigated experimentally. The anaerobic biodegradability of grass can be enhanced through codigestion with CM. When the volatile solid(VS) ratio of CM to grass was 20:80, C/N ratio calculated to be 21.70, the cumulative biogas yield was the highest, 237 ml·(g VS)^(-1). The enhancement of biogas production was attributed to the buffering effects of ammonia and rich trace elements in CM. In semi-continuous systems, when the organic loading rate was 4.0 g VS·L^(-1)·d^(-1), the HSAD process was stable, with the average biogas yield 168 ml·(g VS)^(-1). More than 80% fractions of the digestates were volatile matters, which meant that the digestates can be used as feedstock for gasification to produce syngas. The VS ratio of grass to CM had significant overall energy generation through HSAD and gasification. Compared with gasification of digestate,cogasification with woodchips increased syngas yield and low heat value(LHV). Increasing of mass ratio of digestates to woodchips led to the decrease of LHV.展开更多
Organochlorine biocides （OCBs）, such as lindane and dichlorodi- phenyltrichloroethane （DDT）, have been used for control of vector- borne diseases in public health and for insect pest control in agri- culture. Thes...Organochlorine biocides （OCBs）, such as lindane and dichlorodi- phenyltrichloroethane （DDT）, have been used for control of vector- borne diseases in public health and for insect pest control in agri- culture. These chemicals are extremely persistent in the environ- ment and they tend to bioaccumulate via food chains, thus posing risk to human and ecological health （Cooney et al., 2010; Wang et al., 2013）. Due to their persistence in the environment and continuous use in certain countries despite the banning of some of these chemicals, monitoring and studies of OCBs have continued intensely and remain relevant in foreseeable future （ Cohn et al.,展开更多
Wastewater treatment plants(WWTPs)are traditionally known as energy-intensive facilities,where substantial energy consumption not only results in higher operational costs but also contributes to significant indirect c...Wastewater treatment plants(WWTPs)are traditionally known as energy-intensive facilities,where substantial energy consumption not only results in higher operational costs but also contributes to significant indirect carbon emissions.These emissions,primarily stemming from energy use,contradict the global agenda of achieving carbon neutrality.This review investigates strategies for transforming WWTPs into energy self-sufficient systems.First,the main sources of energy consumption within WWTPs are identified,along with key influencing factors such as treatment technologies,plant scale,and operational strategies.Based on this foundation,three main pathways toward energy neutrality are systematically examined:(1)energy conservation,(2)energy recovery,and(3)utilization of external renewable energy sources.A comprehensive analysis of emerging energy-saving technologies in wastewater treatment processes is presented,followed by a detailed discussion on the recovery potential of embedded energy in wastewater,including organic energy,thermal energy,and hydraulic energy.Recent advances in energy regeneration technologies and their feasibility of application in WWTPs are also reviewed.Additionally,several case studies of WWTPs that have successfully implemented these strategies are examined to demonstrate the practical effectiveness of transitioning toward energy neutrality.Finally,a roadmap is proposed to achieve energy self-sufficiency in WWTPs,emphasizing a core strategy of“carbon redirection+anaerobic digestion of sludge”for energy recovery,complemented by energy conservation measures and renewable energy utilization.The technical route is supported by practical calculations of potential energy savings.Despite promising progress,further empirical studies are necessary to verify these strategies under varying conditions and to explore optimized approaches for future energy-neutral wastewater management.展开更多
Secondary water supply systems(SWSSs)are pivotal in urban water management.Municipal water entering SWSS storage tank undergoes hydraulic stagnation before being distributed to end users.This stagnation provides a sta...Secondary water supply systems(SWSSs)are pivotal in urban water management.Municipal water entering SWSS storage tank undergoes hydraulic stagnation before being distributed to end users.This stagnation provides a stable microenvironment,facilitating a series of chemical reactions,particularly chlorine disinfectant decay resulting in favorable conditions for microbial proliferation.Elevated microbial loads within SWSSs directly compromise the microbiological safety of residential drinking water.In this review,we compile the findings from our studies and existing literature and systematically evaluate the latent microbial hazards in SWSSs serving both urban residential neighborhoods and self-built houses.SWSSs function as persistent reservoirs for pathogenic microbiota.We propose Legionella spp.as targeted supplementary microbiological indicators for routine waterquality monitoring in SWSSs.To mitigate the risks,we advocate implementing three-tiered interventions:1)an optimized building layout and operation mode,2)engineered secondary disinfection strategies,and 3)enhanced regulatory oversight through smart monitoring frameworks.In summary,we characterize the microbial contamination mechanisms in urban SWSSs and establish a vital scientific basis for advancing operational management and safety assurance.展开更多
Light collection efficiency is an important factor that affects the performance of many optical and optoelectronic devices.In these devices,the high reflectivity of interfaces can hinder efficient light collection.To ...Light collection efficiency is an important factor that affects the performance of many optical and optoelectronic devices.In these devices,the high reflectivity of interfaces can hinder efficient light collection.To minimize unwanted reflection,anti-reflection surfaces can be fabricated by micro/nanopatterning.In this paper,we investigate the fabrication of broadband anti-reflection Si surfaces by laser micro/nanoprocessing.Laser direct writing is applied to create microstructures on Si surfaces that reduce light reflection by light trapping.In addition,laser interference lithography and metal assisted chemical etching are adopted to fabricate the Si nanowire arrays.The anti-reflection performance is greatly improved by the high aspect ratio subwavelength structures,which create gradients of refractive index from the ambient air to the substrate.Furthermore,by decoration of the Si nanowires with metallic nanoparticles,surface plasmon resonance can be used to further control the broadband reflections,reducing the reflection to below 1.0%across from 300 to 1200 nm.An average reflection of 0.8%is achieved.展开更多
Oxidation of organic pollutants by sulfate radicals produced via activation of persulfate has emerged as a promising advanced oxidation technology to address various challenging environmental issues. The development o...Oxidation of organic pollutants by sulfate radicals produced via activation of persulfate has emerged as a promising advanced oxidation technology to address various challenging environmental issues. The development of an effective, environmentally-friendly, metal-free catalyst is the key to this technology. Additionally, a supported catalyst design is more advantageous than conventional suspended powder catalysts from the point of view of mass transfer and practical engineering applications （e.g. post-use separation）. In this study, a metal-free N-doped reduced graphene oxide （N-rGO） catalyst was prepared via a facile hydrothermal method. N-rGO filters were then synthesized by facile vacuum filtration, such that water can flow through nanochannels within the filters. Various advanced characterization techniques were employed to obtain structural and compositional information of the as-synthesized N-rGO filters. An optimized phenol oxidative flux of 0.036 ＋_ 0.002 mmol.h ~ was obtained by metal-flee catalytic activation of persulfate at an influent persulfate concentration of 1.0 mmol-L 1 and filter weight of 15 rag, while a N-free rGO filter demonstrated negligible phenol oxidation capability under similar conditions. Compared to a conventional batch system, the flow-through design demonstrates obviously enhanced oxidation kinetics （0.036 vs. 0.010 retool-h-I）, mainly due to the liquid flow through the filter leading to convection-enhanced transfer of the target molecule to the filter active sites. Overall, the results exemplified the advantages of organic compound removal by catalytic activation of persulfate using a metal-free catalyst in flow- through mode, and demonstrated the potential of N-rGO filters for practical environmental applications.展开更多
Fluorescent light-up probes comprising a tetraphenylethene unit with aggregation-induced emission(AIE)characteristics and a water-soluble peptide have been designed and synthesized which provide cell membrane and nucl...Fluorescent light-up probes comprising a tetraphenylethene unit with aggregation-induced emission(AIE)characteristics and a water-soluble peptide have been designed and synthesized which provide cell membrane and nuclear permeability to live cells.This strategy has offered new opportunities for the development of probes with light-up ability and good signal-to-noise ratio.The selectivity or targeting specificity is determined by the peptide sequence,i.e.a nuclear localization signal that leads to nucleus imaging and a cell biomarker targeting peptide that offers specific light-up imaging of HT-29 cells.展开更多
Summary Soy and its quest for future food production.Soy,or soybean(Glycine max),is a leguminous plant that has played a significant role in various civilizations throughout human history.Soybeans are native to East A...Summary Soy and its quest for future food production.Soy,or soybean(Glycine max),is a leguminous plant that has played a significant role in various civilizations throughout human history.Soybeans are native to East Asia and have been cultivated in China for thousands of years.As a food source,soy has a wide range of uses,they include tofu,tempeh,soy milk,soy sauce,miso,soy-based meat alternatives,desserts and snacks.These products serve as alternatives to animal-based proteins and dairy products for vegetarians,vegans,and individuals with dietary restrictions.In addition,soybean oil is one of the most widely consumed cooking oils globally.It is used for frying,baking,sautéing,and salad dressings due to its mild flavour and high smoke point.Soybean oil is also used as an ingredient in margarine,mayonnaise,and other food products.展开更多
This study aims to investigate the significance and biodegradation pathways of PHB-based bioplastic in anaerobic digesters treating food waste,where the reactor performance of changed methane generation,bioplastic bio...This study aims to investigate the significance and biodegradation pathways of PHB-based bioplastic in anaerobic digesters treating food waste,where the reactor performance of changed methane generation,bioplastic biodegradation efficiency,and bioinformatic analysis of functional microbes were emphasized.The results showed that PHB-based plastic film could be partially biodegraded in the food waste digester,and a bioaugmentation use of Alcaligenes Faecalis(AF)and Bacillus Megaterium(BM)was beneficial to largely accelerate the degradation process through a beneficial shift of both the functional bacterial and archaeal species.Microbial community analysis indicated that the major bacterial species belonged to genera Candidatus_Cloacimonas,Rikenellaceae,and Defluviitoga,while the dominant methanogenic archaeal species belonged to genera Methanomassiliicoccus,Methanosarcina,and Methanosaeta.Bioplastic biodegradation analysis suggested that the optimal fractions of AF and BM for PHB-based plastic degradation were 50% AF and 75% BM,respectively,which deserves further optimization and scale-up validation.The finding of this study would contribute to the combined management of PHB-based bioplastic with food waste for clean energy recovery and a greener environment.展开更多
基金the National Research Foundation(NRF),Prime Minister’s Office,Singapore,under its Campus for Research Excellence and Technological Enterprise(CREATE)program(A-0001032-01-00)the National Natural Science Foundation of China(52376011).
文摘The increasing population and continuous urbanization make food security a key consideration in sustainable development.Efficient farming strategies with low environmental footprints are thus increasingly required to meet food demands.This study presents a design for environmentally friendly,economical,and modular vertical farming systems,in which vegetables are cultivated in a carbon dioxide(CO_(2))-enriched atmosphere enabled by direct air capture(DAC)and subjected to artificial light exposure.We established a vertical farming setup and conducted experiments to identify productive cultivation strategies by regulating lighting,CO_(2)concentration,biochar application,and plant species.Additionally,a self-developed DAC rotary adsorber was utilized to achieve stable and efficient CO_(2)enrichment.Compared with the control group,the fresh weight of the vegetables in the experimental groups increased by up to 57.5%.Furthermore,we performed a comprehensive evaluation of the design and demonstrated that integrating photovoltaic-thermal(PVT)and DAC units increased the system’s net present value(NPV)by 157%compared with a conventional design without these units.Importantly,we found it possible to maintain the low carbon footprint of the system(0.468 kg-CO_(2)equivalent·kg−1(CO_(2)eq·kg−1)-vegetable)in the production process.Parametric studies and an application analysis on a global scale reveal the wide adaptability of this strategy to diverse conditions.These findings,together with the modular characteristics of vertical farming systems,highlight the promising potential of this design to increase food security and foster sustainable agriculture.
基金financially supported by the National Key Research and Development Program of China(2023YFD1600600 and 2021YFD1600105-03)the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(GZB20240665)+1 种基金the Special Funding for Postdoctoral Research Projects in Zhejiang(ZJ2024044)the China Postdoctoral Science Foundation(2024M762848)。
文摘Inspired by the remarkable surface wetting behavior of natural organisms,artificially designed superwettable systems have attracted significant attention from multidisciplinary scientists over the past two decades.Starch is an eco-friendly,nontoxic,and low-cost natural polymer that serves as an alternative to nonbiodegradable and/or bioincompatible synthetic polymers in these systems.This review explores the unique contributions of starch to superwettable systems from design principles to emerging applications.First,the fundamental theories and design principles underlying starch-involved superwettable systems are introduced.The specific design principles of these systems are comprehensively discussed from the aspects of intrinsic properties(e.g.,hydrophilicity,film-forming properties,adhesiveness,and thermal decomposition),dimensionality(e.g.,colloidal systems,zero-dimensional granules/particles,one-dimensional fibers,two-dimensional films/fibrous membranes/coatings,and three-dimensional fillers/porous materials/food textures),and biotransformation.It also provides an overview of their applications in functio nal biomaterials,oral delivery systems,emulsion polymerizatio n,packaging technology,food taste modulation,and water treatment,with particular emphasis on intelligent systems.Each section summarizes recent advancements,highlighting the chemical and structural features.Finally,the review considers prospects for these superwettable systems,focusing on underutilized starch attributes and technical challenges.
基金supported by the Scientific and Innovative Action Plan of Shanghai(CN)“One Belt One Road”International Cooperation Project(No.20260750400)the Singapore National Research Foundation(NRF)under its Campus for Research Excellence and Technological Enterprise(CREATE)program(E2S2-CREATE project ES-2:Detection,Assessment&Modelling of Emerging Contaminants in the Urban Environment)。
文摘The rapid construction of artificial reservoirs in metropolises has promoted the emergence of city-river-reservoir systems worldwide.This study investigated the environmental behaviors and risks of heavy metals in the aquatic environment of a typical system composed of main watersheds in Suzhou and Jinze Reservoir in Shanghai.Results shown that Mn,Zn and Cu were the dominant metals detected in multiple phases.Cd,Mn and Zn were mainly presented in exchangeable fraction and exhibited high bioavailability.Great proportion and high mobility of metals were found in suspended particulate matter(SPM),suggesting that SPM can greatly affect metal multi-phase distribution process.Spatially,city system(Ci S)exhibited more serious metal pollution and higher ecological risk than river system(Ri S)and reservoir system(Re S)owing to the diverse emission sources.Ci S and Re S were regarded as critical pollution source and sink,respectively,while Ri S was a vital transportation aisle.Microbial community in sediments exhibited evident spatial variation and obviously modified by exchangeable metals and nutrients.In particular,Bacteroidetes and Firmicutes presented significant positive correlations with most exchangeable metals.Risk assessment implied that As,Sb and Ni in water may pose potential carcinogenic risk to human health.Nevertheless,Re S was in a fairly safe state.Hg was the main risk contributor in SPM,while Cu,Zn,Ni and Sb showed moderate risk in sediments.Overall,Hg,Sb and Ci S were screened out as priority metals and system,respectively.More attention should be paid to these priority issues to promote the sustainable development of the watershed.
基金supported by the National Natural Science Foundation of China (No.21677097)the National Science and Technology Major Projects of Water Pollution Control and Management of China (No.2014ZX07206001)the National Research Foundation (NRF),Singapore under its Campus for Research Excellence and Technological Enterprise (CREATE) Program
文摘With increasing emission of silver nanoparticles(AgNPs) into the environment, it is important to understand the effects of ambient concentration of AgNPs. The biological effects of AgNPs on Scenedesmus obliquus, a ubiquitous freshwater microalgae, was evaluated. AgNPs exerted a minor inhibitory effect at low doses. Non-targeted metabolomic studies were conducted to understand and analyze the effect of AgNPs on algal cells from a molecular perspective. During the 48 hr of exposure to AgNPs, 30 metabolites were identified, of which nine had significant changes compared to the control group. These include D-galactose, sucrose, and D-fructose.These carbohydrates are involved in the synthesis and repair of cell walls. Glycine, an important constituent amino acid of glutathione, increased with AgNP exposure concentration increasing, likely to counteract an increased intracellular oxidative stress. These results provide a new understanding of the toxicity effects and mechanism of AgNPs. These metabolites could be useful biomarkers for future research, employed in the early detection of environmental risk from AgNPs.
基金financial supports from the National Natural Science Foundation of China (No.61403138)Beijing Natural Science Foundation (No.3202028)+1 种基金funded by the National Research Foundation (NRF), Prime Minister’s Offce, Singapore under its Campus for Research Excellence and Technological Enterprise (CREATE) programmeGrant Number R-706-001-102–281, National University of Singapore。
文摘The flow dynamics of binary particle mixtures in the fluidized bed needs to be monitored in order to optimize the related industrial processes.In this paper,electrostatic sensing and high-speed imaging are applied to measure the velocities of polyethylene and sand particles in the binary particle mixtures in fluidization.Experimental studies were conducted on a lab-scale cold circulating fluidized bed.Correlation function between electrostatic signals from upstream and downstream electrodes placed along the riser shows two peaks that represent transit times for the two types of particles.To verify the above results,high-speed imaging was adopted to capture the flow images of particle mixtures.Particle Image Velocimetry and Particle Tracking Velocimetry algorithms were utilized to process the resulted images in order to measure the velocities of polyethylene and sand particles.The reasons for two-peak correlation functions are illustrated based on the frequency spectrums of the mono-solid-phase electrostatic signals and the velocity difference between polyethylene and sand particles.Finally,comparisons on the velocities obtained from electrostatic sensing and high-speed imaging demonstrate the electrostatic sensor can roughly estimate the particle velocity of binary particle mixtures in the near wall region of the circulating fluidized bed.
基金Supported by the National Research Foundation,Prime Minister’s Office,Singapore under its Campus for Research Excellence and Technological Enterprise(CREATE)programme
文摘To realize full energy recovery from grass and chicken manure(CM), the integration of high-solid anaerobic digestion(HSAD) and gasification was investigated experimentally. The anaerobic biodegradability of grass can be enhanced through codigestion with CM. When the volatile solid(VS) ratio of CM to grass was 20:80, C/N ratio calculated to be 21.70, the cumulative biogas yield was the highest, 237 ml·(g VS)^(-1). The enhancement of biogas production was attributed to the buffering effects of ammonia and rich trace elements in CM. In semi-continuous systems, when the organic loading rate was 4.0 g VS·L^(-1)·d^(-1), the HSAD process was stable, with the average biogas yield 168 ml·(g VS)^(-1). More than 80% fractions of the digestates were volatile matters, which meant that the digestates can be used as feedstock for gasification to produce syngas. The VS ratio of grass to CM had significant overall energy generation through HSAD and gasification. Compared with gasification of digestate,cogasification with woodchips increased syngas yield and low heat value(LHV). Increasing of mass ratio of digestates to woodchips led to the decrease of LHV.
基金supported by the Singapore National Research Foundation under its Environmental&Water Technologies Strategic Research Programmeadministered by the Environment&Water Industry Programme Office(EWI)of PUB
文摘Organochlorine biocides （OCBs）, such as lindane and dichlorodi- phenyltrichloroethane （DDT）, have been used for control of vector- borne diseases in public health and for insect pest control in agri- culture. These chemicals are extremely persistent in the environ- ment and they tend to bioaccumulate via food chains, thus posing risk to human and ecological health （Cooney et al., 2010; Wang et al., 2013）. Due to their persistence in the environment and continuous use in certain countries despite the banning of some of these chemicals, monitoring and studies of OCBs have continued intensely and remain relevant in foreseeable future （ Cohn et al.,
基金supported by Shanghai Chengtou Water Group Co.Ltd.Scientific Research Reserve Project(No.KY.WB.23.001).
文摘Wastewater treatment plants(WWTPs)are traditionally known as energy-intensive facilities,where substantial energy consumption not only results in higher operational costs but also contributes to significant indirect carbon emissions.These emissions,primarily stemming from energy use,contradict the global agenda of achieving carbon neutrality.This review investigates strategies for transforming WWTPs into energy self-sufficient systems.First,the main sources of energy consumption within WWTPs are identified,along with key influencing factors such as treatment technologies,plant scale,and operational strategies.Based on this foundation,three main pathways toward energy neutrality are systematically examined:(1)energy conservation,(2)energy recovery,and(3)utilization of external renewable energy sources.A comprehensive analysis of emerging energy-saving technologies in wastewater treatment processes is presented,followed by a detailed discussion on the recovery potential of embedded energy in wastewater,including organic energy,thermal energy,and hydraulic energy.Recent advances in energy regeneration technologies and their feasibility of application in WWTPs are also reviewed.Additionally,several case studies of WWTPs that have successfully implemented these strategies are examined to demonstrate the practical effectiveness of transitioning toward energy neutrality.Finally,a roadmap is proposed to achieve energy self-sufficiency in WWTPs,emphasizing a core strategy of“carbon redirection+anaerobic digestion of sludge”for energy recovery,complemented by energy conservation measures and renewable energy utilization.The technical route is supported by practical calculations of potential energy savings.Despite promising progress,further empirical studies are necessary to verify these strategies under varying conditions and to explore optimized approaches for future energy-neutral wastewater management.
基金supported by the Shandong Provincial Natural Science Foundation of China(No.ZR2023QE252)the Scientific Research Start-up Fund of Shandong First Medical University.
文摘Secondary water supply systems(SWSSs)are pivotal in urban water management.Municipal water entering SWSS storage tank undergoes hydraulic stagnation before being distributed to end users.This stagnation provides a stable microenvironment,facilitating a series of chemical reactions,particularly chlorine disinfectant decay resulting in favorable conditions for microbial proliferation.Elevated microbial loads within SWSSs directly compromise the microbiological safety of residential drinking water.In this review,we compile the findings from our studies and existing literature and systematically evaluate the latent microbial hazards in SWSSs serving both urban residential neighborhoods and self-built houses.SWSSs function as persistent reservoirs for pathogenic microbiota.We propose Legionella spp.as targeted supplementary microbiological indicators for routine waterquality monitoring in SWSSs.To mitigate the risks,we advocate implementing three-tiered interventions:1)an optimized building layout and operation mode,2)engineered secondary disinfection strategies,and 3)enhanced regulatory oversight through smart monitoring frameworks.In summary,we characterize the microbial contamination mechanisms in urban SWSSs and establish a vital scientific basis for advancing operational management and safety assurance.
基金The authors would like to acknowledge financial support from the National Research Foundation,Prime Minister’s Office,Singapore under its Competitive Research Program(CRP Award No.NRF-CRP10-2012-04)the Economic Development Board(SPORE,COY-15-EWI-RCFSA/N197-1)The authors would also like to acknowledge funding provided by the Chinese Nature Science Grant(61138002)and 973 Program of China(No.2013CBA01700).
文摘Light collection efficiency is an important factor that affects the performance of many optical and optoelectronic devices.In these devices,the high reflectivity of interfaces can hinder efficient light collection.To minimize unwanted reflection,anti-reflection surfaces can be fabricated by micro/nanopatterning.In this paper,we investigate the fabrication of broadband anti-reflection Si surfaces by laser micro/nanoprocessing.Laser direct writing is applied to create microstructures on Si surfaces that reduce light reflection by light trapping.In addition,laser interference lithography and metal assisted chemical etching are adopted to fabricate the Si nanowire arrays.The anti-reflection performance is greatly improved by the high aspect ratio subwavelength structures,which create gradients of refractive index from the ambient air to the substrate.Furthermore,by decoration of the Si nanowires with metallic nanoparticles,surface plasmon resonance can be used to further control the broadband reflections,reducing the reflection to below 1.0%across from 300 to 1200 nm.An average reflection of 0.8%is achieved.
文摘Oxidation of organic pollutants by sulfate radicals produced via activation of persulfate has emerged as a promising advanced oxidation technology to address various challenging environmental issues. The development of an effective, environmentally-friendly, metal-free catalyst is the key to this technology. Additionally, a supported catalyst design is more advantageous than conventional suspended powder catalysts from the point of view of mass transfer and practical engineering applications （e.g. post-use separation）. In this study, a metal-free N-doped reduced graphene oxide （N-rGO） catalyst was prepared via a facile hydrothermal method. N-rGO filters were then synthesized by facile vacuum filtration, such that water can flow through nanochannels within the filters. Various advanced characterization techniques were employed to obtain structural and compositional information of the as-synthesized N-rGO filters. An optimized phenol oxidative flux of 0.036 ＋_ 0.002 mmol.h ~ was obtained by metal-flee catalytic activation of persulfate at an influent persulfate concentration of 1.0 mmol-L 1 and filter weight of 15 rag, while a N-free rGO filter demonstrated negligible phenol oxidation capability under similar conditions. Compared to a conventional batch system, the flow-through design demonstrates obviously enhanced oxidation kinetics （0.036 vs. 0.010 retool-h-I）, mainly due to the liquid flow through the filter leading to convection-enhanced transfer of the target molecule to the filter active sites. Overall, the results exemplified the advantages of organic compound removal by catalytic activation of persulfate using a metal-free catalyst in flow- through mode, and demonstrated the potential of N-rGO filters for practical environmental applications.
基金the Singapore National Research Foundation(R279-000-444-281)the Singapore-MIT Alliance for Research and Technology(R279-000-378-592)the Economic Development Board(Singapore-Peking-Oxford Research Enterprise,COY-15EWI-RCFSA/N197-1)
文摘Fluorescent light-up probes comprising a tetraphenylethene unit with aggregation-induced emission(AIE)characteristics and a water-soluble peptide have been designed and synthesized which provide cell membrane and nuclear permeability to live cells.This strategy has offered new opportunities for the development of probes with light-up ability and good signal-to-noise ratio.The selectivity or targeting specificity is determined by the peptide sequence,i.e.a nuclear localization signal that leads to nucleus imaging and a cell biomarker targeting peptide that offers specific light-up imaging of HT-29 cells.
基金supported by the National Research Foundation,Prime Minister’s Office,Singapore(Grant No.NRF-2020-THE003-0005).
文摘Summary Soy and its quest for future food production.Soy,or soybean(Glycine max),is a leguminous plant that has played a significant role in various civilizations throughout human history.Soybeans are native to East Asia and have been cultivated in China for thousands of years.As a food source,soy has a wide range of uses,they include tofu,tempeh,soy milk,soy sauce,miso,soy-based meat alternatives,desserts and snacks.These products serve as alternatives to animal-based proteins and dairy products for vegetarians,vegans,and individuals with dietary restrictions.In addition,soybean oil is one of the most widely consumed cooking oils globally.It is used for frying,baking,sautéing,and salad dressings due to its mild flavour and high smoke point.Soybean oil is also used as an ingredient in margarine,mayonnaise,and other food products.
基金funded by the National Research Foundation,Prime Minister’s Office,Singapore under its Campus for Research Excellence and Technological Enterprise(CREATE)Programme.
文摘This study aims to investigate the significance and biodegradation pathways of PHB-based bioplastic in anaerobic digesters treating food waste,where the reactor performance of changed methane generation,bioplastic biodegradation efficiency,and bioinformatic analysis of functional microbes were emphasized.The results showed that PHB-based plastic film could be partially biodegraded in the food waste digester,and a bioaugmentation use of Alcaligenes Faecalis(AF)and Bacillus Megaterium(BM)was beneficial to largely accelerate the degradation process through a beneficial shift of both the functional bacterial and archaeal species.Microbial community analysis indicated that the major bacterial species belonged to genera Candidatus_Cloacimonas,Rikenellaceae,and Defluviitoga,while the dominant methanogenic archaeal species belonged to genera Methanomassiliicoccus,Methanosarcina,and Methanosaeta.Bioplastic biodegradation analysis suggested that the optimal fractions of AF and BM for PHB-based plastic degradation were 50% AF and 75% BM,respectively,which deserves further optimization and scale-up validation.The finding of this study would contribute to the combined management of PHB-based bioplastic with food waste for clean energy recovery and a greener environment.
