A widely employed energy technology,known as reverse electrodialysis(RED),holds the promise of delivering clean and renewable electricity from water.This technology involves the interaction of two or more bodies of wa...A widely employed energy technology,known as reverse electrodialysis(RED),holds the promise of delivering clean and renewable electricity from water.This technology involves the interaction of two or more bodies of water with varying concentrations of salt ions.The movement of these ions across a membrane generates electricity.However,the efficiency of these systems faces a challenge due to membrane performance degradation over time,often caused by channel blockages.One potential solution to enhance system efficiency is the use of nanofluidic membranes.These specialized membranes offer high ion exchange capacity,abundant ion sources,and customizable channels with varying sizes and properties.Graphene oxide(GO)-based membranes have emerged as particularly promising candidates in this regard,garnering significant attention in recent literature.This work provides a comprehensive overview of the literature surrounding GO membranes and their applications in RED systems.It also highlights recent advancements in the utilization of GO membranes within these systems.Finally,it explores the potential of these membranes to play a pivotal role in electricity generation within RED systems.展开更多
In this article we give an overview of the state of the art of salinity gradient technologies. We first introduce the concept of salinity gradient energy, before describing the current state of development of the most...In this article we give an overview of the state of the art of salinity gradient technologies. We first introduce the concept of salinity gradient energy, before describing the current state of development of the most advanced of these technologies. We conclude with the new trends in the young field of salinity gradient technologies.展开更多
The development of novel materials with ion-selective nanochannels has introduced a new technology for harvesting salinity gradient(blue)energy,namely nanopore power generators(NPGs).In this study,we perform a compreh...The development of novel materials with ion-selective nanochannels has introduced a new technology for harvesting salinity gradient(blue)energy,namely nanopore power generators(NPGs).In this study,we perform a comprehensive analysis of the practical performance of NPG in both coupon-size and module-scale operations.We show that although NPG membrane coupons can theoretically generate ultrahigh power density under ideal conditions,the resulting power density in practical operations at a coupon scale can hardly reach 10 W·m^(-2) due to concentration polarization effects.For module-scale NPG operation,we estimate both the power density and specific extractable energy(i.e.,extractable energy normalized by the total volume of the working solutions),and elucidate the impact of operating conditions on these two metrics based on the interplay between concentration polarization and extent of mixing of the high-and low-concentration solutions.Further,we develop a modeling framework to assess the viability of an NPG system.Our results demonstrate that,for NPG systems working with seawater and river water,the gross specific extractable energy by the NPG system is very low(~0.1 kW?h?m?3)and is further compromised by the parasitic energy consumptions in the system(notably,pumping of the seawater and river water solutions and their pretreatment).Overall,NPG systems produce very low net specific extractable energy(<0.025 kW?h?m?3)and net power density(<0.1 W?m?2).Our study highlights the significant practical limitations in NPG operations,casting doubt on the viability of NPG as a technology for blue energy harvesting.展开更多
A polymeric nanopore membrane with selective ionic transport has been proposed as a potential device to convert the chemical potential energy in salinity gradients to electrical power. However, its energy conversion e...A polymeric nanopore membrane with selective ionic transport has been proposed as a potential device to convert the chemical potential energy in salinity gradients to electrical power. However, its energy conversion efficiency and power density are often limited due to the challenge in reliably controlling the size of the nanopores with the conventional chemical etching method. Here we report that without chemical etching, polyimide （PI） membranes irradiated with GeV heavy ions have negatively charged nanopores, showing nearly perfect selectivity for cations over anions, and they can generate electrical power from salinity gradients. We further demonstrate that the power generation efficiency of the PI membrane approaches the theoretical limit, and the maximum power density reaches 130m W/m2 with a modified etching method, outperforming the previous energy conversion device that was made of polymeric nanopore membranes.展开更多
SalinityGradient Solar Ponds(SGSPs)offer the potential to capture and store solar energy for use in a range of domestic and industrial activities in regions with high solar insolation.However,the evaporation of water ...SalinityGradient Solar Ponds(SGSPs)offer the potential to capture and store solar energy for use in a range of domestic and industrial activities in regions with high solar insolation.However,the evaporation of water from these ponds is a significant problem that must be overcome for them to be deployed successfully.Thus,two ponds were constructed in the city of Nasiriya,Iraq.The two ponds were cylindrical with a diameter of 1.4 m and a total depth of 1.4 m.The water body in the two ponds was constructed with layer depths of 0.5,0.75 and 0.1 m for the lower convective zone(LCZ),non-convective zone(NCZ)and the upper convective zone(UCZ)respectively.One of the two ponds was covered with a thin liquid paraffin layer(0.5 cm)to eliminate evaporation from the surface of the UCZ.The behavior of the standard SGSP and that of the covered pond with evaporation suppressed can be straightforwardly compared.The experimental units were run for six months from 1st of February to 31st of July 2019.It was shown in the first instance that by covering the pond with a thin layer of paraffin,that evaporation could be suppressed.The results showed that for the conventional SGSP,the temperature of the LCZ reached a maximum of ca.76℃ while in the covered pond the temperature of the LCZ was consistently lower than that in the uncovered pond by approximately 5-6℃.The results also indicated that the temperature of the UCZ in the covered pond was higher than that in the uncovered pond by about 10℃ in the second half of the study period.However,it was noted that on rainy days the paraffin layer was swept away from the surface;and this could hinder the implementation of thin liquid cover in the large SGSP.展开更多
Membrane fouling inevitably occurs during nanofluidic reverse electrodialysis.Herein,the impact of multi-fouling on the energy conversion performance of negatively charged conical nanochannels under asymmetrical confi...Membrane fouling inevitably occurs during nanofluidic reverse electrodialysis.Herein,the impact of multi-fouling on the energy conversion performance of negatively charged conical nanochannels under asymmetrical configurations is systematically investigated.The results reveal that in Configuration I,where a high-concentration solution is applied at the tip side,at small concentration ratios,multiple foulings reduce the electric power.In Configuration II,where a low-concentration solution is applied at the tip side,multiple foulings near the base side contribute to the electric power.Any fouling that formed near the lowconcentration entrance diminished the electric power and energy conversion efficiency.Multi-fouling lowered the electrical power consumption by 69.27%and 99.94%in Configurations I and II,respectively.In Configuration I,the electric power first increased with increasing fouling surface charge density,reached its maximum value,and thereafter decreased.In Configuration II,the electric power first decreased with increasing fouling surface charge density,reached its minimum value,and thereafter increased.Large negative or positive charge densities of fouling contribute to the electric power and energy conversion efficiency.展开更多
In this study,a novel irreversible cyclic model of a capacitive mixing blue heat engine mainly consisting of super capacitors,charging and discharging circuits,a heat source,as well as two water sources with given sal...In this study,a novel irreversible cyclic model of a capacitive mixing blue heat engine mainly consisting of super capacitors,charging and discharging circuits,a heat source,as well as two water sources with given salt concentrations is established for harvesting salinity gradient energy and waste heat.Additionally,the effects of the charging voltage and ratio of the minimum to maximum surface electric charge density on the thermodynamic efficiency and power output of the cycle are discussed.The maximum power output of the cycle is calculated.The optimized ranges of efficiency and power output as well as the temperatures of two isothermal processes are determined.It is established that during the isoelectric quantity process,there is not only an increase in thermal voltage owing to the temperature difference,but also an increase in concentration voltage owing to the salinity gradient.Consequently,the blue heat engine can obtain higher energy conversion efficiency than a conventional heat engine.When the temperature ratio of the heat source to the heat sink is 1.233,the maximum efficiency can reach approximately36%.The results obtained can promote the application of capacitive mixing technology in real life,reducing the consumption of fossil fuels.展开更多
Due to the combined effect of sluices and sea tide,the sluice-controlled coastal plain river would be characterized by both trophic state and salinity gradients,affecting the spatiotemporal optical properties of disso...Due to the combined effect of sluices and sea tide,the sluice-controlled coastal plain river would be characterized by both trophic state and salinity gradients,affecting the spatiotemporal optical properties of dissolved organicmatter(DOM).In this study,we investigated the spatiotemporal variation of water quality parameters and optical properties of DOM in the Haihe River,a representative sluice-controlled coastal plain river in Tianjin,China.A significant salinity gradient and four trophic states were observed in the water body of the Haihe River.Two humic-and one protein-like substances were identified from the DOM by the three-dimensional fluorescence spectra combined with the parallel factor(PARAFAC)analysis.Pearson’s correlation analysis and redundancy analysis(RDA)showed that the salinity significantly affected the abundance of chromophoric DOM(CDOM)but did not cause significant changes in the fluorescence optical characteristics.In addition,the effect of Trophic state index(TSI)on the CDOM abundance was greater than that on the fluorescence intensity of fluorescent dissolved organic matter(FDOM).In the water body with both salinity and trophic state gradients,TSI posed a greater influence than salinity on the CDOM abundance.Our results fill the research gap in spatiotemporal DOM characteristics and water quality variation in water bodies with both salinity and trophic state gradients.These results are beneficial for clarifying the joint influence of saline intrusion and sluices on the DOM characteristics and water quality in sluice-controlled coastal plain rivers.展开更多
Heterogeneity of soil salinity is a prominent environmental characteristic in the intertidal zone of estuaries,affecting the plant growth and the shift of biotic interactions in the salt marsh.This study aims to exami...Heterogeneity of soil salinity is a prominent environmental characteristic in the intertidal zone of estuaries,affecting the plant growth and the shift of biotic interactions in the salt marsh.This study aims to examine the interactive effects of a salinity gradient and salinity fluctuations on intraspecific interactions of a euhalophyte.We assessed the impact of daily fluctuating salinity on the outcome of intraspecific interactions by cultivating seeds of Suaeda salsa(Chenopodiaceae)in river sand.The experiment was conducted in a greenhouse with three treatments:daily salinity fluctuations(static and fluctuating salinity),a salinity gradient(200 and 400 mmol L^(−1))and three planting densities(1,2 and 4 plants/pot).First,height and biomass of plants were measured at both the start and end of the experiment.Then,the growth indexes and log response ratio of S.salsa were analyzed.The outcome of intraspecific interactions of S.salsa shifted from competition in low salinity to facilitation in high salinity,and high conspecific density strengthened the competition and facilitation intensities.Daily salinity fluctuation did not significantly affect the plant growth and the outcome of intraspecific interactions,but did have a significant influence on belowground biomass.Our results suggest that the stress-gradient hypothesis may apply to predicting the variation of the intraspecific relationship of a salt-tolerant species along a salinity gradient,and the magnitude of this variation is density dependent.These findings help us understand how individuals and populations of a euhalophyte species respond to the natural variation or human modification of salinity conditions.展开更多
Coupling low-grade heat(LGH)with salinity gradient is an effective approach to increase the efficiency of the nanofluidic-membrane-based power generator.However,it is a challenge to fabricate membranes with high charg...Coupling low-grade heat(LGH)with salinity gradient is an effective approach to increase the efficiency of the nanofluidic-membrane-based power generator.However,it is a challenge to fabricate membranes with high charge density that ensures ion permselectivity,while maintaining chemical and mechanical stability in this composite environment.Here,we develop a bis[2-(methacryloyloxy)ethyl]phosphate(BMAP)hydrogel membrane with good thermal stability and anti-swelling property through self-crosslinking of the selected monomer.By taking advantage of negative space charge and three-dimensional(3D)interconnected nanochannels,salinity gradient energy conversion efficiency is substantially enhanced by temperature difference.Theoretical and experimental results verify that LGH can largely weaken the concentration polarization,promoting transmembrane ion transport.As a result,such a hydrogel membrane delivers high-performance energy conversion with a power density of 11.53 W·m^(−2)under a negative temperature difference(NTD),showing a 193%increase compared with that without NTD.展开更多
Based on the rapid advancements in nanomaterials and nanotechnology,the Nanofluidic Reverse Electrodialysis(NRED)has attracted significant attention as an innovative and promising energy conversion strategy for extrac...Based on the rapid advancements in nanomaterials and nanotechnology,the Nanofluidic Reverse Electrodialysis(NRED)has attracted significant attention as an innovative and promising energy conversion strategy for extracting sustainable and clean energy fromthe salinity gradient energy.However,the scarcity of research investigating the intricate multi-factor coupling effects on the energy conversion performance,especially the trade-offs between ion selectivity and mass transfer in nanochannels,of NRED poses a great challenge to achieving breakthroughs in energy conversion processes.This numerical study innovatively investigates the multi-factor coupling effect of three critical operational factors,including the nanochannel configuration,the temperature field,and the concentration difference,on the energy conversion processes of NRED.In this work,a dimensionless amplitude parameter s is introduced to emulate the randomly varied wall configuration of nanochannels that inherently occur in practical applications,thereby enhancing the realism and applicability of our analysis.Numerical results reveal that the application of a temperature gradient,which is oriented in opposition to the concentration gradient,enhances the ion transportation and selectivity simultaneously,leading to an enhancement in both output power and energy conversion efficiency.Additionally,the increased fluctuation of the nanochannel wall from s=0 to s=0.08 improves ion selectivity yet raises ion transport resistance,resulting in an enhancement in output power and energy conversion efficiency but a slight reduction in current.Furthermore,with increasing the concentration ratio cH/cL from 10 to 1000,either within a fixed temperature field or at a constant dimensionless amplitude,the maximumpower consistently attains its optimal value at a concentration ratio of 100 but the cation transfer number experiences amonotonic decrease across this entire range of concentration ratios.Finally,uponmodifying the operational parameters fromthe baseline condition of s=0,c_(H)/c_(L)=10,andΔT=0 K to the targetedconditionof s=0.08,c_(H)/c_(L)=50,andΔT=25 K,there is a concerted improvement observed in the open-circuit potential,short-circuit current,andmaximumpower,with respective increments of 8.86%,204.97%,and 232.01%,but a reduction in cation transfer number with a notable decrease of 15.37%.展开更多
The river plume front between the diluted ocean water and salty ocean water in the Changjiang(Yangtze)River Delta(CRD)is well studied.Comparatively,less is known about the estuarine front in the CRD,which is formed be...The river plume front between the diluted ocean water and salty ocean water in the Changjiang(Yangtze)River Delta(CRD)is well studied.Comparatively,less is known about the estuarine front in the CRD,which is formed between the riverine freshwater and the diluted ocean water and has the highest magnitude of salinity gradient(SG)in the CRD.Estuarine fronts are of great significance to the riverine material transport in the estuary.Many biogeochemical processes are enhanced in estuarine fronts,which have brought about environmental problems.In this study,the seasonal variations of the estuarine fronts in the CRD were studied in wet(July)and dry(January)seasons in 2017,based on model simulations with high spatiotemporal resolutions using the Finite-Volume Community Ocean Model(FVCOM).The estuarine front included several sharp fronts with a SG>4(/500 m),and was bottom-trapped on the submerged delta front.Seasonal changes mainly occurred off the Jiangsu coast,where a significant estuarine front was formed in July.The estuarine fronts generated around the submerged delta topography were accompanied by the offshore extension of older estuarine fronts,which were diluted and evolved into plume fronts over a tidal cycle.The simulated estuarine fronts had a salinity range of 6 to 22 in the dry season and 6 to 14 in wet season 2017.The estuarine fronts hindered the residual current by altering its flow direction to the southeast.展开更多
Although estuarine tidal marshes are important contributors to the emission of greenhouse gases into the atmosphere, the relationship between carbon dioxide（CO2）, methane（CH4）emission, and environmental factors, w...Although estuarine tidal marshes are important contributors to the emission of greenhouse gases into the atmosphere, the relationship between carbon dioxide（CO2）, methane（CH4）emission, and environmental factors, with respect to estuarine marshes, has not been clarified thoroughly. This study investigated the crucial factors controlling the emission of CO2 and CH4from a freshwater marsh and a brackish marsh located in a subtropical estuary in southeastern China, as well as their magnitude. The duration of the study period was November 2013 to October 2014. Relevant to both the field and incubation experiments, the CO2 and CH4emissions from the two marshes showed pronounced seasonal variations. The CO2 and CH4emissions from both marshes demonstrated significant positive correlations with the air/soil temperature（p 〈 0.01）, but negative correlations with the soil electrical conductivity and the pore water/tide water Cl-and SO42- （p 〈 0.01）. The results indicate no significant difference in the CO2 emissions between the freshwater and brackish marshes in the subtropical estuary, whereas there was a difference in the CH4 emissions between the two sites（p 〈 0.01）. Although future sea-level rise and saltwater intrusion could reduce the CH4 emissions from the estuarine freshwater marshes, these factors had little effect on the CO2 emissions with respect to an increase in salinity of less than 5‰. The findings of this study could have important implications for estimating the global warming contributions of estuarine marshes along differing salinity gradients.展开更多
To evaluate the relationship between salinity tolerance and genetic diversity of plankton,we collected a wild species of plankton from Taipingjiao,Qingdao.The fragment of ITS1-5.8S rDNA-ITS2 was extracted and sequence...To evaluate the relationship between salinity tolerance and genetic diversity of plankton,we collected a wild species of plankton from Taipingjiao,Qingdao.The fragment of ITS1-5.8S rDNA-ITS2 was extracted and sequenced.The results showed that the plankton belongs to Oxyrrhis marina.The salinity tolerance of O.marina ranges from 4 to 60.Seven selected groups were built up to evaluate salinity tolerance and to assess genetic diversity by RAPD.The salinity tolerance comparison revealed considerable differences among groups:the strains of O.marina in group 4 could survive under salinity from 4 to 32,while the strains selected for salinity 60 died under the salinity lower than 16.Analysis of genetic diversity of the seven groups showed that the mean genetic diversity index value was 0.28,but it was only 0.16 in selected group of 4 and was 0.24 for group 60.The result of AMOVA suggested a significantly positive relationship between the salinity tolerance and genetic diversity of O.marina (P<0.01).This study indicates that consideration of intraspecific genetic divergence in O.marina might be indispensable when using it as a model in the study of salinity tolerance of wild plankton.展开更多
Algae(and their extracts)are increasingly important for pharmaceutical applications due to the diversity of useful compounds they contain.The genus Fucus contains one of the most studied species,Fucus vesiculosus.The ...Algae(and their extracts)are increasingly important for pharmaceutical applications due to the diversity of useful compounds they contain.The genus Fucus contains one of the most studied species,Fucus vesiculosus.The species F.ceranoides differs from the others of the genus by presenting longitudinal air-vesicles and a capacity to survive at low salinities.It is an alga that inhabits the Mondego River estuary(Portugal),at the southern limit of its distribution,and can serve as a role model to understand the effect of a salt gradient on the production of bioactive compounds.We assessed the phenolic content and antioxidant activity of different F.ceranoides extracts(e.g.methanolic,aqueous and polysaccharide)prepared from samples harvested from two different zones to evaluate if the adaptation of F.ceranoides to different salinity levels influenced its chemical composition.The antioxidant activity of the extracts was determined using 1,2-diphenyl-picrylhydrazyl(DPPH)and 2.2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS)radicals.These assays demonstrated that the methanolic extract of lyophilized F.ceranoides that grew at low salinities was the most bioactive,i.e.DPPH(IC 50=50.39μg/mL)and ABTS(TEAC=2.42).The total phenolic content(Folin-Ciocalteu method)and the methanolic extract of the lyophilized F.ceranoides collected from a low salinity habitat exhibited the highest phenolic content(PGE=49.48μg/mg of lyophilized extract)amongst those sampled.Thin layer chromatography(TLC)and Fourier transform infrared spectroscopy(FTIR)were used for the identification of compounds in the extracts.This characterization allowed confirmation that the various extracts contained almost the same compounds but with notable quantitative differences.Based on these results,we conclude that there were differences in the quantity of the compounds due to the effect of salinity.The drying methods used were also found to have influenced the quality of the extracted compounds.展开更多
The increasing demand due to development and advancement in every field of life has caused the depletion of fossil fuels.This depleting fossil fuel reserve throughout the world has enforced to get energy from alternat...The increasing demand due to development and advancement in every field of life has caused the depletion of fossil fuels.This depleting fossil fuel reserve throughout the world has enforced to get energy from alternative/renewable sources.One of the economicalways to get energy is through the utilization of solar ponds.In this study,a mathematical model of a salt gradient solar pond under the Islamabad climatic conditions has been analyzed for the first time.The model uses a one-dimensional finite difference explicit method for optimization of different zone thicknesses.The model depicts that NCZ(Non-Convective Zone)thickness has a significant effect on LCZ(Lower Convective Zone)temperature and should be kept less than 1.7mfor the optimal temperature.It is also observed that for long-termoperation of a solar pond,heat should be extracted by keeping the mass flowrate of 17.3 kg/m^(2)/day.Themodel also suggests that when the bottom reflectivity is about 0.3,then only 24%of the radiation is absorbed in the pond.展开更多
Based on a general review of marine renewable energy in China, an assessment of the development status and amount of various marine renewable energy resources, including tidal energy, tidal current energy, wave energy...Based on a general review of marine renewable energy in China, an assessment of the development status and amount of various marine renewable energy resources, including tidal energy, tidal current energy, wave energy, ocean thermal energy, and salinity gradient energy in China＇s coastal seas, such as the Bohai Sea, the Yellow Sea, the East China Sea, and the South China Sea, is presented. We have found that these kinds of marine renewable energy resources will play an important role in meeting China＇s future energy needs. Additionally, considering the uneven distribution of China＇s marine renewable energy and the influences of its exploitation on the environment, we have suggested several sites with great potential for each kind of marine energy. Furthermore, perspectives on and challenges related with marine renewable energy in China are addressed.展开更多
The practical application of semiconductor-based high-efficiency white-light sources, also known as light-emitting diodes, or LEDs, is a recent development of Japanese engineering. This development could be a game-cha...The practical application of semiconductor-based high-efficiency white-light sources, also known as light-emitting diodes, or LEDs, is a recent development of Japanese engineering. This development could be a game-changer for lighting worldwide, given that current power consumption for lighting accounts for 16% of the total electricity consumption in Japan.展开更多
Estuaries are environments where freshwater and seawater mix and they display various salinity profiles.The construction of river barrages and dams has rapidly changed these environments and has had a wide range of im...Estuaries are environments where freshwater and seawater mix and they display various salinity profiles.The construction of river barrages and dams has rapidly changed these environments and has had a wide range of impacts on plankton communities.To understand the dynamics of such communities,researchers need accurate and rapid techniques for detecting plankton species.We evaluated the diversity of eukaryotic plankton over a salinity gradient by applying a metagenomics tool at the Nakdong River estuary in Korea.Environmental samples were collected on three dates during summer and autumn of 2011 at the Eulsukdo Bridge at the mouth of that river.Amplifying the 18 S rDNA allowed us to analyze 456 clones and 122 phylotypes.Metagenomic sequences revealed various taxonomic groups and cryptic genetic variations at the intra-and inter-specific levels.By analyzing the same station at each sampling date,we observed that the phylotypes presented a salinity-related pattern of diversity in assemblages.The variety of species within freshwater samples reflected the rapid environmental changes caused by freshwater inputs.Dinophyceae phylotypes accounted for the highest proportion of overall diversity in the seawater samples.Euryhaline diatoms and dinoflagellates were observed in the freshwater,brackish and seawater samples.The biological data for species composition demonstrate the transitional state between freshwater and seawater.Therefore,this metagenomics information can serve as a biological indicator for tracking changes in aquatic environments.展开更多
As blue energy,osmotic power holds tremendous potential for electricity generation via membranebased reverse electrodialysis.However,current processes suffer from low energy output mainly due to inadequate transmembra...As blue energy,osmotic power holds tremendous potential for electricity generation via membranebased reverse electrodialysis.However,current processes suffer from low energy output mainly due to inadequate transmembrane ion transport and a polarization phenomenon.Inspired by plant growth and photosynthesis,we proposed a robust heterogeneous membrane that enabled ionic-diode rectified and light-enhanced ion transport for efficient osmotic-solar energy harvesting.The membrane was rationally constructed by in-situ growth of polyaniline(PANI)onto a sulfonated matrix,creating a multiscale heterostructure that enabled the coexistence of a Janus-like architecture and semiconductor heterojunction.Benefiting from multi-asymmetries of geometry,charge,and chemistry,the membrane delivered a high unidirectional ion flow and suppressed polarization,generating an exceptional osmotic power density of up to 12.6Wm^(−2)at a 50-fold salinity gradient.Light-driven ion pumping was achieved by the synergistic photothermal and photoelectric effect of PANI heterojunction.Under light irradiation,temperature gradient and transmembrane potential were triggered simultaneously,accelerating ion movement,thereby elevating the energy conversion output.This work pioneers the development of highperformance power generators capable of harnessing energy from diverse salty sources coupled with a solar resource.展开更多
基金Key Research and Development Program of Zhejiang Province,Grant/Award Number:2021C04019National Natural Science Foundation of China,Grant/Award Number:U20A20338Natural Science Foundation of Zhejiang Province,Grant/Award Number:LQ21H180012.
文摘A widely employed energy technology,known as reverse electrodialysis(RED),holds the promise of delivering clean and renewable electricity from water.This technology involves the interaction of two or more bodies of water with varying concentrations of salt ions.The movement of these ions across a membrane generates electricity.However,the efficiency of these systems faces a challenge due to membrane performance degradation over time,often caused by channel blockages.One potential solution to enhance system efficiency is the use of nanofluidic membranes.These specialized membranes offer high ion exchange capacity,abundant ion sources,and customizable channels with varying sizes and properties.Graphene oxide(GO)-based membranes have emerged as particularly promising candidates in this regard,garnering significant attention in recent literature.This work provides a comprehensive overview of the literature surrounding GO membranes and their applications in RED systems.It also highlights recent advancements in the utilization of GO membranes within these systems.Finally,it explores the potential of these membranes to play a pivotal role in electricity generation within RED systems.
文摘In this article we give an overview of the state of the art of salinity gradient technologies. We first introduce the concept of salinity gradient energy, before describing the current state of development of the most advanced of these technologies. We conclude with the new trends in the young field of salinity gradient technologies.
基金financial support from the Center for Enhanced Nanofluidic Transport (CENT),an Energy Frontier Research Center funded by the US Department of Energy,Office of Science,Basic Energy Sciences through Award No.DESC0019112
文摘The development of novel materials with ion-selective nanochannels has introduced a new technology for harvesting salinity gradient(blue)energy,namely nanopore power generators(NPGs).In this study,we perform a comprehensive analysis of the practical performance of NPG in both coupon-size and module-scale operations.We show that although NPG membrane coupons can theoretically generate ultrahigh power density under ideal conditions,the resulting power density in practical operations at a coupon scale can hardly reach 10 W·m^(-2) due to concentration polarization effects.For module-scale NPG operation,we estimate both the power density and specific extractable energy(i.e.,extractable energy normalized by the total volume of the working solutions),and elucidate the impact of operating conditions on these two metrics based on the interplay between concentration polarization and extent of mixing of the high-and low-concentration solutions.Further,we develop a modeling framework to assess the viability of an NPG system.Our results demonstrate that,for NPG systems working with seawater and river water,the gross specific extractable energy by the NPG system is very low(~0.1 kW?h?m?3)and is further compromised by the parasitic energy consumptions in the system(notably,pumping of the seawater and river water solutions and their pretreatment).Overall,NPG systems produce very low net specific extractable energy(<0.025 kW?h?m?3)and net power density(<0.1 W?m?2).Our study highlights the significant practical limitations in NPG operations,casting doubt on the viability of NPG as a technology for blue energy harvesting.
基金Supported by the National Natural Science Foundation of China under Grant No 11335003
文摘A polymeric nanopore membrane with selective ionic transport has been proposed as a potential device to convert the chemical potential energy in salinity gradients to electrical power. However, its energy conversion efficiency and power density are often limited due to the challenge in reliably controlling the size of the nanopores with the conventional chemical etching method. Here we report that without chemical etching, polyimide （PI） membranes irradiated with GeV heavy ions have negatively charged nanopores, showing nearly perfect selectivity for cations over anions, and they can generate electrical power from salinity gradients. We further demonstrate that the power generation efficiency of the PI membrane approaches the theoretical limit, and the maximum power density reaches 130m W/m2 with a modified etching method, outperforming the previous energy conversion device that was made of polymeric nanopore membranes.
文摘SalinityGradient Solar Ponds(SGSPs)offer the potential to capture and store solar energy for use in a range of domestic and industrial activities in regions with high solar insolation.However,the evaporation of water from these ponds is a significant problem that must be overcome for them to be deployed successfully.Thus,two ponds were constructed in the city of Nasiriya,Iraq.The two ponds were cylindrical with a diameter of 1.4 m and a total depth of 1.4 m.The water body in the two ponds was constructed with layer depths of 0.5,0.75 and 0.1 m for the lower convective zone(LCZ),non-convective zone(NCZ)and the upper convective zone(UCZ)respectively.One of the two ponds was covered with a thin liquid paraffin layer(0.5 cm)to eliminate evaporation from the surface of the UCZ.The behavior of the standard SGSP and that of the covered pond with evaporation suppressed can be straightforwardly compared.The experimental units were run for six months from 1st of February to 31st of July 2019.It was shown in the first instance that by covering the pond with a thin layer of paraffin,that evaporation could be suppressed.The results showed that for the conventional SGSP,the temperature of the LCZ reached a maximum of ca.76℃ while in the covered pond the temperature of the LCZ was consistently lower than that in the uncovered pond by approximately 5-6℃.The results also indicated that the temperature of the UCZ in the covered pond was higher than that in the uncovered pond by about 10℃ in the second half of the study period.However,it was noted that on rainy days the paraffin layer was swept away from the surface;and this could hinder the implementation of thin liquid cover in the large SGSP.
基金supported by the National Natural Science Foundation of China(Grant No.52176070)。
文摘Membrane fouling inevitably occurs during nanofluidic reverse electrodialysis.Herein,the impact of multi-fouling on the energy conversion performance of negatively charged conical nanochannels under asymmetrical configurations is systematically investigated.The results reveal that in Configuration I,where a high-concentration solution is applied at the tip side,at small concentration ratios,multiple foulings reduce the electric power.In Configuration II,where a low-concentration solution is applied at the tip side,multiple foulings near the base side contribute to the electric power.Any fouling that formed near the lowconcentration entrance diminished the electric power and energy conversion efficiency.Multi-fouling lowered the electrical power consumption by 69.27%and 99.94%in Configurations I and II,respectively.In Configuration I,the electric power first increased with increasing fouling surface charge density,reached its maximum value,and thereafter decreased.In Configuration II,the electric power first decreased with increasing fouling surface charge density,reached its minimum value,and thereafter increased.Large negative or positive charge densities of fouling contribute to the electric power and energy conversion efficiency.
基金supported by the National Natural Science Foundation of China(Grant No.51876181)。
文摘In this study,a novel irreversible cyclic model of a capacitive mixing blue heat engine mainly consisting of super capacitors,charging and discharging circuits,a heat source,as well as two water sources with given salt concentrations is established for harvesting salinity gradient energy and waste heat.Additionally,the effects of the charging voltage and ratio of the minimum to maximum surface electric charge density on the thermodynamic efficiency and power output of the cycle are discussed.The maximum power output of the cycle is calculated.The optimized ranges of efficiency and power output as well as the temperatures of two isothermal processes are determined.It is established that during the isoelectric quantity process,there is not only an increase in thermal voltage owing to the temperature difference,but also an increase in concentration voltage owing to the salinity gradient.Consequently,the blue heat engine can obtain higher energy conversion efficiency than a conventional heat engine.When the temperature ratio of the heat source to the heat sink is 1.233,the maximum efficiency can reach approximately36%.The results obtained can promote the application of capacitive mixing technology in real life,reducing the consumption of fossil fuels.
基金This work was supported by the National Science Foundation of China(No.41807386).The authors gratefully acknowledge the warm help from Prof.Baoli Wang and PhD studentWanzhu Li during themeasurement of chlorophyll a.We greatly appreciate Prof.Wei He for his help in the use of the efc toolbox.We are deeply grateful to Prof.Jinyu Yang for her warm suggestion in the statistical analysis.We thank all staff and students that helped with sample collection and measurements.Scientific compass(www.shiyanjia.com)is gratefully appreciated for their service in the polish of manuscript.
文摘Due to the combined effect of sluices and sea tide,the sluice-controlled coastal plain river would be characterized by both trophic state and salinity gradients,affecting the spatiotemporal optical properties of dissolved organicmatter(DOM).In this study,we investigated the spatiotemporal variation of water quality parameters and optical properties of DOM in the Haihe River,a representative sluice-controlled coastal plain river in Tianjin,China.A significant salinity gradient and four trophic states were observed in the water body of the Haihe River.Two humic-and one protein-like substances were identified from the DOM by the three-dimensional fluorescence spectra combined with the parallel factor(PARAFAC)analysis.Pearson’s correlation analysis and redundancy analysis(RDA)showed that the salinity significantly affected the abundance of chromophoric DOM(CDOM)but did not cause significant changes in the fluorescence optical characteristics.In addition,the effect of Trophic state index(TSI)on the CDOM abundance was greater than that on the fluorescence intensity of fluorescent dissolved organic matter(FDOM).In the water body with both salinity and trophic state gradients,TSI posed a greater influence than salinity on the CDOM abundance.Our results fill the research gap in spatiotemporal DOM characteristics and water quality variation in water bodies with both salinity and trophic state gradients.These results are beneficial for clarifying the joint influence of saline intrusion and sluices on the DOM characteristics and water quality in sluice-controlled coastal plain rivers.
基金supported by the Fundamental Research Funds for the Central Non-Profit Research Institution of Chinese Academy of Forestry(CAFYBB2016SY034,key technologies of functional restoration and directional improvement of mudflat wetland)the National Key R&D Program of China(2017YFC0506200)the Research on the synchronicity of dichogamy in Scirpus planiculmis based on population clonal structure(NSFC31800348).
文摘Heterogeneity of soil salinity is a prominent environmental characteristic in the intertidal zone of estuaries,affecting the plant growth and the shift of biotic interactions in the salt marsh.This study aims to examine the interactive effects of a salinity gradient and salinity fluctuations on intraspecific interactions of a euhalophyte.We assessed the impact of daily fluctuating salinity on the outcome of intraspecific interactions by cultivating seeds of Suaeda salsa(Chenopodiaceae)in river sand.The experiment was conducted in a greenhouse with three treatments:daily salinity fluctuations(static and fluctuating salinity),a salinity gradient(200 and 400 mmol L^(−1))and three planting densities(1,2 and 4 plants/pot).First,height and biomass of plants were measured at both the start and end of the experiment.Then,the growth indexes and log response ratio of S.salsa were analyzed.The outcome of intraspecific interactions of S.salsa shifted from competition in low salinity to facilitation in high salinity,and high conspecific density strengthened the competition and facilitation intensities.Daily salinity fluctuation did not significantly affect the plant growth and the outcome of intraspecific interactions,but did have a significant influence on belowground biomass.Our results suggest that the stress-gradient hypothesis may apply to predicting the variation of the intraspecific relationship of a salt-tolerant species along a salinity gradient,and the magnitude of this variation is density dependent.These findings help us understand how individuals and populations of a euhalophyte species respond to the natural variation or human modification of salinity conditions.
基金supported by the National Key R&D Program of China(Nos.2022YFB3805904,2022YFB3805900,and 2020YFA0710401)the National Natural Science Foundation of China(Nos.22122207,21988102,and 52075138)+2 种基金CAS Key Laboratory of Bio-inspired Materials and Interfacial Science,Technical Institute of Physics and Chemistry(No.BMIS202102)China Postdoctoral Science Foundation(Nos.2022TQ0345,2022M723229,and 2022M713226)Postdoctoral International Exchange Talent-Introducing Program(No.YJ20220199).
文摘Coupling low-grade heat(LGH)with salinity gradient is an effective approach to increase the efficiency of the nanofluidic-membrane-based power generator.However,it is a challenge to fabricate membranes with high charge density that ensures ion permselectivity,while maintaining chemical and mechanical stability in this composite environment.Here,we develop a bis[2-(methacryloyloxy)ethyl]phosphate(BMAP)hydrogel membrane with good thermal stability and anti-swelling property through self-crosslinking of the selected monomer.By taking advantage of negative space charge and three-dimensional(3D)interconnected nanochannels,salinity gradient energy conversion efficiency is substantially enhanced by temperature difference.Theoretical and experimental results verify that LGH can largely weaken the concentration polarization,promoting transmembrane ion transport.As a result,such a hydrogel membrane delivers high-performance energy conversion with a power density of 11.53 W·m^(−2)under a negative temperature difference(NTD),showing a 193%increase compared with that without NTD.
基金funded by the National Natural Science Foundation of China[52106246]the Postgraduate Research&Practice innovation Program of Jiangsu Province[KYCX24_1641].
文摘Based on the rapid advancements in nanomaterials and nanotechnology,the Nanofluidic Reverse Electrodialysis(NRED)has attracted significant attention as an innovative and promising energy conversion strategy for extracting sustainable and clean energy fromthe salinity gradient energy.However,the scarcity of research investigating the intricate multi-factor coupling effects on the energy conversion performance,especially the trade-offs between ion selectivity and mass transfer in nanochannels,of NRED poses a great challenge to achieving breakthroughs in energy conversion processes.This numerical study innovatively investigates the multi-factor coupling effect of three critical operational factors,including the nanochannel configuration,the temperature field,and the concentration difference,on the energy conversion processes of NRED.In this work,a dimensionless amplitude parameter s is introduced to emulate the randomly varied wall configuration of nanochannels that inherently occur in practical applications,thereby enhancing the realism and applicability of our analysis.Numerical results reveal that the application of a temperature gradient,which is oriented in opposition to the concentration gradient,enhances the ion transportation and selectivity simultaneously,leading to an enhancement in both output power and energy conversion efficiency.Additionally,the increased fluctuation of the nanochannel wall from s=0 to s=0.08 improves ion selectivity yet raises ion transport resistance,resulting in an enhancement in output power and energy conversion efficiency but a slight reduction in current.Furthermore,with increasing the concentration ratio cH/cL from 10 to 1000,either within a fixed temperature field or at a constant dimensionless amplitude,the maximumpower consistently attains its optimal value at a concentration ratio of 100 but the cation transfer number experiences amonotonic decrease across this entire range of concentration ratios.Finally,uponmodifying the operational parameters fromthe baseline condition of s=0,c_(H)/c_(L)=10,andΔT=0 K to the targetedconditionof s=0.08,c_(H)/c_(L)=50,andΔT=25 K,there is a concerted improvement observed in the open-circuit potential,short-circuit current,andmaximumpower,with respective increments of 8.86%,204.97%,and 232.01%,but a reduction in cation transfer number with a notable decrease of 15.37%.
基金Supported by the National Natural Science Foundation of China(No.U2240220)。
文摘The river plume front between the diluted ocean water and salty ocean water in the Changjiang(Yangtze)River Delta(CRD)is well studied.Comparatively,less is known about the estuarine front in the CRD,which is formed between the riverine freshwater and the diluted ocean water and has the highest magnitude of salinity gradient(SG)in the CRD.Estuarine fronts are of great significance to the riverine material transport in the estuary.Many biogeochemical processes are enhanced in estuarine fronts,which have brought about environmental problems.In this study,the seasonal variations of the estuarine fronts in the CRD were studied in wet(July)and dry(January)seasons in 2017,based on model simulations with high spatiotemporal resolutions using the Finite-Volume Community Ocean Model(FVCOM).The estuarine front included several sharp fronts with a SG>4(/500 m),and was bottom-trapped on the submerged delta front.Seasonal changes mainly occurred off the Jiangsu coast,where a significant estuarine front was formed in July.The estuarine fronts generated around the submerged delta topography were accompanied by the offshore extension of older estuarine fronts,which were diluted and evolved into plume fronts over a tidal cycle.The simulated estuarine fronts had a salinity range of 6 to 22 in the dry season and 6 to 14 in wet season 2017.The estuarine fronts hindered the residual current by altering its flow direction to the southeast.
基金was supported by the National Natural Science Foundation of China(No.41371127)the Program for Innovative Research Teams of Fujian Normal University(No.IRTL1205)+1 种基金the Key Sciences and Technology Project of Fujian Province(No.2014R1034-1)the Graduate Innovation Project of the School of Geographical Sciences of Fujian Normal University(No.GY201501)
文摘Although estuarine tidal marshes are important contributors to the emission of greenhouse gases into the atmosphere, the relationship between carbon dioxide（CO2）, methane（CH4）emission, and environmental factors, with respect to estuarine marshes, has not been clarified thoroughly. This study investigated the crucial factors controlling the emission of CO2 and CH4from a freshwater marsh and a brackish marsh located in a subtropical estuary in southeastern China, as well as their magnitude. The duration of the study period was November 2013 to October 2014. Relevant to both the field and incubation experiments, the CO2 and CH4emissions from the two marshes showed pronounced seasonal variations. The CO2 and CH4emissions from both marshes demonstrated significant positive correlations with the air/soil temperature（p 〈 0.01）, but negative correlations with the soil electrical conductivity and the pore water/tide water Cl-and SO42- （p 〈 0.01）. The results indicate no significant difference in the CO2 emissions between the freshwater and brackish marshes in the subtropical estuary, whereas there was a difference in the CH4 emissions between the two sites（p 〈 0.01）. Although future sea-level rise and saltwater intrusion could reduce the CH4 emissions from the estuarine freshwater marshes, these factors had little effect on the CO2 emissions with respect to an increase in salinity of less than 5‰. The findings of this study could have important implications for estimating the global warming contributions of estuarine marshes along differing salinity gradients.
文摘To evaluate the relationship between salinity tolerance and genetic diversity of plankton,we collected a wild species of plankton from Taipingjiao,Qingdao.The fragment of ITS1-5.8S rDNA-ITS2 was extracted and sequenced.The results showed that the plankton belongs to Oxyrrhis marina.The salinity tolerance of O.marina ranges from 4 to 60.Seven selected groups were built up to evaluate salinity tolerance and to assess genetic diversity by RAPD.The salinity tolerance comparison revealed considerable differences among groups:the strains of O.marina in group 4 could survive under salinity from 4 to 32,while the strains selected for salinity 60 died under the salinity lower than 16.Analysis of genetic diversity of the seven groups showed that the mean genetic diversity index value was 0.28,but it was only 0.16 in selected group of 4 and was 0.24 for group 60.The result of AMOVA suggested a significantly positive relationship between the salinity tolerance and genetic diversity of O.marina (P<0.01).This study indicates that consideration of intraspecific genetic divergence in O.marina might be indispensable when using it as a model in the study of salinity tolerance of wild plankton.
基金the support of Fundacao para a Ciência e Tecnologia(FCT),through the strategic project UID/MAR/04292/2013 granted to MAREfunding from European Structural&Investment Funds through the COMPETE ProgrammeNational Funds through FCT-Fundacao para a Ciência e a Tecnologia under the Programme(No.SAICTPAC/0019/2015)
文摘Algae(and their extracts)are increasingly important for pharmaceutical applications due to the diversity of useful compounds they contain.The genus Fucus contains one of the most studied species,Fucus vesiculosus.The species F.ceranoides differs from the others of the genus by presenting longitudinal air-vesicles and a capacity to survive at low salinities.It is an alga that inhabits the Mondego River estuary(Portugal),at the southern limit of its distribution,and can serve as a role model to understand the effect of a salt gradient on the production of bioactive compounds.We assessed the phenolic content and antioxidant activity of different F.ceranoides extracts(e.g.methanolic,aqueous and polysaccharide)prepared from samples harvested from two different zones to evaluate if the adaptation of F.ceranoides to different salinity levels influenced its chemical composition.The antioxidant activity of the extracts was determined using 1,2-diphenyl-picrylhydrazyl(DPPH)and 2.2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS)radicals.These assays demonstrated that the methanolic extract of lyophilized F.ceranoides that grew at low salinities was the most bioactive,i.e.DPPH(IC 50=50.39μg/mL)and ABTS(TEAC=2.42).The total phenolic content(Folin-Ciocalteu method)and the methanolic extract of the lyophilized F.ceranoides collected from a low salinity habitat exhibited the highest phenolic content(PGE=49.48μg/mg of lyophilized extract)amongst those sampled.Thin layer chromatography(TLC)and Fourier transform infrared spectroscopy(FTIR)were used for the identification of compounds in the extracts.This characterization allowed confirmation that the various extracts contained almost the same compounds but with notable quantitative differences.Based on these results,we conclude that there were differences in the quantity of the compounds due to the effect of salinity.The drying methods used were also found to have influenced the quality of the extracted compounds.
文摘The increasing demand due to development and advancement in every field of life has caused the depletion of fossil fuels.This depleting fossil fuel reserve throughout the world has enforced to get energy from alternative/renewable sources.One of the economicalways to get energy is through the utilization of solar ponds.In this study,a mathematical model of a salt gradient solar pond under the Islamabad climatic conditions has been analyzed for the first time.The model uses a one-dimensional finite difference explicit method for optimization of different zone thicknesses.The model depicts that NCZ(Non-Convective Zone)thickness has a significant effect on LCZ(Lower Convective Zone)temperature and should be kept less than 1.7mfor the optimal temperature.It is also observed that for long-termoperation of a solar pond,heat should be extracted by keeping the mass flowrate of 17.3 kg/m^(2)/day.Themodel also suggests that when the bottom reflectivity is about 0.3,then only 24%of the radiation is absorbed in the pond.
基金supported by the National Natural Science Foundation of China(Grants No.51079072 and 51279088)the National High Technology Research and Development Program of China(Grant No.2012AA052602)the Tsinghua University Initiative Scientific Research Program(Grant No.20101081791)
文摘Based on a general review of marine renewable energy in China, an assessment of the development status and amount of various marine renewable energy resources, including tidal energy, tidal current energy, wave energy, ocean thermal energy, and salinity gradient energy in China＇s coastal seas, such as the Bohai Sea, the Yellow Sea, the East China Sea, and the South China Sea, is presented. We have found that these kinds of marine renewable energy resources will play an important role in meeting China＇s future energy needs. Additionally, considering the uneven distribution of China＇s marine renewable energy and the influences of its exploitation on the environment, we have suggested several sites with great potential for each kind of marine energy. Furthermore, perspectives on and challenges related with marine renewable energy in China are addressed.
文摘The practical application of semiconductor-based high-efficiency white-light sources, also known as light-emitting diodes, or LEDs, is a recent development of Japanese engineering. This development could be a game-changer for lighting worldwide, given that current power consumption for lighting accounts for 16% of the total electricity consumption in Japan.
基金Supported by the East Asian Seas Time Series-I(No.EAST-I)the Ministry of Oceans and Fisheries,Korea,the"Development of Microbial Metagenomic Techniques for a Fine-Scale Seawater Mass Analysis"through the Ministry of Education of the Republic of Koreathe National Research Foundation of Korea(No.NRF-2013R1A1A2006915)
文摘Estuaries are environments where freshwater and seawater mix and they display various salinity profiles.The construction of river barrages and dams has rapidly changed these environments and has had a wide range of impacts on plankton communities.To understand the dynamics of such communities,researchers need accurate and rapid techniques for detecting plankton species.We evaluated the diversity of eukaryotic plankton over a salinity gradient by applying a metagenomics tool at the Nakdong River estuary in Korea.Environmental samples were collected on three dates during summer and autumn of 2011 at the Eulsukdo Bridge at the mouth of that river.Amplifying the 18 S rDNA allowed us to analyze 456 clones and 122 phylotypes.Metagenomic sequences revealed various taxonomic groups and cryptic genetic variations at the intra-and inter-specific levels.By analyzing the same station at each sampling date,we observed that the phylotypes presented a salinity-related pattern of diversity in assemblages.The variety of species within freshwater samples reflected the rapid environmental changes caused by freshwater inputs.Dinophyceae phylotypes accounted for the highest proportion of overall diversity in the seawater samples.Euryhaline diatoms and dinoflagellates were observed in the freshwater,brackish and seawater samples.The biological data for species composition demonstrate the transitional state between freshwater and seawater.Therefore,this metagenomics information can serve as a biological indicator for tracking changes in aquatic environments.
基金support of the National Natural Science Foundation of China(NSFCgrant no.21991123).
文摘As blue energy,osmotic power holds tremendous potential for electricity generation via membranebased reverse electrodialysis.However,current processes suffer from low energy output mainly due to inadequate transmembrane ion transport and a polarization phenomenon.Inspired by plant growth and photosynthesis,we proposed a robust heterogeneous membrane that enabled ionic-diode rectified and light-enhanced ion transport for efficient osmotic-solar energy harvesting.The membrane was rationally constructed by in-situ growth of polyaniline(PANI)onto a sulfonated matrix,creating a multiscale heterostructure that enabled the coexistence of a Janus-like architecture and semiconductor heterojunction.Benefiting from multi-asymmetries of geometry,charge,and chemistry,the membrane delivered a high unidirectional ion flow and suppressed polarization,generating an exceptional osmotic power density of up to 12.6Wm^(−2)at a 50-fold salinity gradient.Light-driven ion pumping was achieved by the synergistic photothermal and photoelectric effect of PANI heterojunction.Under light irradiation,temperature gradient and transmembrane potential were triggered simultaneously,accelerating ion movement,thereby elevating the energy conversion output.This work pioneers the development of highperformance power generators capable of harnessing energy from diverse salty sources coupled with a solar resource.
