Experimental Study on Corrosion of Stainless Steel in Low Temperature Multi effect Seawater Desalination

Starting from the corrosion mechanism,this paper analyzes the characteristics of various types of stainless steel and selects the best performance composite plate composite plate stainless steel.Analyze and select the most suitable corrosion detection method based on specific practical multi working conditions,discuss the interference factors that affect metal corrosion during experimental simulation,and the advantages of newly developed sheet metal.The new development of composite board panels,with the substrate and composite materials applying their respective capabilities for MED,will bring breakthrough progress to the scientific research and engineering applica-tion of composite boards.

Renewable Energy Seawater Desalination Technology and Application Analysis

This paper proposed a new technology way for seawater desalination which used renewable energy(wind energy and solar energy).The effects of practical application showed that remote islands and cage culture zones in the bay that lack electricity and water are very suitable for using small seawater desalination devices that do not require consumption of conventional energy.

China's Seawater Desalination Plants Produce Megatons Freshwater For Low Cost

China, as many other parts of the world, has a serious shortage of water resources. In China, there is a total amount of 2.8×10^12 m3 of freshwater, but that is only 2000 m3 per capita, which is about one quarter of the world average. Thereforc, seawater desalination engineering is of great significance to the nation.

Nitrogen-doped microporous graphite-enhanced copper plasmonic effect for solar evaporation

Water scarcity is a global challenge,and solar evaporation technology offers a promising and eco-friendly solution for freshwater production.Photothermal conversion materials(PCMs)are crucial for solar evaporation.Improving photothermal conversion efficiency and reducing water evaporation enthalpy are the two key strategies for the designing of PCMs.The desired PCMs that combine both of these properties remain a challenging task,even with the latest advancements in the field.Herein,we developed copper nanoparticles(NPs)with different conjugated nitrogen-doped microporous carbon coatings(Cu@C–N)as PCMs.The microporous carbon enveloping layer provides a highly efficient pathway for water transport and a nanoconfined environment that protects Cu NPs and facilitates the evaporation of water clusters,reducing the enthalpy of water evaporation.Meanwhile,the conjugated nitrogen nodes form strong metal-organic coordination bonds with the surface of copper NPs,acting as an energy bridge to achieve rapid energy transfer and provide high solar-to-vapor conversion efficiency.The Cu@C–N exhibited up to 89.4%solar-to-vapor conversion efficiency and an evaporation rate of 1.94 kgm^(−2) h^(−1) under one sun irradiation,outperforming conventional PCMs,including carbon-based materials and semiconductor materials.These findings offer an efficient design scheme for high-performance PCMs essential for solar evaporators to address global water scarcity.

Integrated energy efficiency evaluation of a multi-source multi-load desalination micro-energy network

With increasing global shortage of fresh water resources,many countries are prioritizing desalination as a means of utilizing abundantly available seawater resources.Integrated energy efficiency evaluation is a scientific method for the quantitative analysis of energy efficiency based on multiple indicators and is very useful for investment,construction,and scientific decision-making for desalination projects.In this paper,the energy efficiency evaluation of the micro energy network (MEN) of desalination for multi-source and multi-load is studied,and the basic idea of comprehensive energy efficiency evaluation is analyzed.The process includes the use of a MEN model to establish an integrated energy efficiency evaluation index system,taking into consideration energy,equipment,economic,environmental,and social factors.A combined evaluation method considering subjective and objective comprehensive weights for multi-source multi-load desalination MENs is proposed to evaluate the energy efficiency of desalination and from multiple perspectives.

Development and interpretation of ISO 13205:2024,Marine technology-Seawater desalination-Vocabulary

Vocabulary is the most basic subject of standardization.Despite that individual terms related to seawater desalination have been mentioned in some standards and technical documents of ISO,WHO,and ASTM,the inconsistent expression might still induce ambiguity in communications among the participators in this area.Moreover,terms in these documents are not comprehensive.Consequently,ISO 13205:2024 is developed to eliminate the misunderstanding in both the academic and commercial communications.This paper expounds on the specific progress of the research in three aspects:background,drafting of ISO 13205:2024,and interpretation of ISO 13205:2024.The significance of the standard is also discussed.

Numerical Analysis of Conjugated Heat and Mass Transfer of Helical Hollow Fiber Membrane Tube Bank for Seawater Distillation

A numerical study on the conjugated heat-mass transfer of helical hollow fiber membrane tube bank(HFMTB)for seawater desalination was carried out.Physical and mathematical models of fluid flow,temperature and humidity distribution were constructed to investigate the influences of flow type,Reynolds number,and temperature on the conjugated heat-mass transfer performance of hollow fibers in the distillation membrane module.The conjugated heat-mass transfer characteristics of HFMTB were discussed by utilizing the friction coefficient,Nusselt number(Nu),and Sherwood number(Sh).Results demonstrate that a distillation efficiency enhancement of 29%compared to the straight HFMTB has been detected for four-helical HFMTB configuration,though the friction coefficient of such a module is about 4 times of their straight counterparts.The values of average Nu and Sh numbers are increasing with tube number,which improves distillation efficiency.The effect of flow type has been studied by employing the upstream and downstream flows to the double-helical HFMTB,demonstrating upstream flow type is more conducive to the heat-mass transfer process.Both the outlet air humidity(ω)and distillation efficiency(η)decrease with the air-side Reynolds number(Rea)and inlet air temperature in the helical HFMTB while increasing with the solution-side Reynolds number(Re_(S))and inlet solution temperature.Overall,the obtained results indicate that helical HFMTB applying upstream flow has great potential to achieve high-performance SGMD for seawater desalination.It is anticipated that the present work can assist in a better understanding of the membrane desalination process in HFMTB and thus provide theoretical suggestions for further optimization and development.

Potential Effects of Desalinated Seawater on Arteriosclerosis in Rats

To evaluate the potential risk of arteriosclerosis caused by desalinated seawater, Wistar rats were provided desalinated seawater over a 1-year period, and blood samples were collected at 0, 90, 180, and 360 days. Blood calcium, magnesium, and arteriosclerosis-related indicators were investigated. Female rats treated with desalinated seawater for 180 days showed lower magnesium levels than the control rats （P 〈 0.05）. The calcium and magnesium levels in female rats and the magnesium level in male rats were lower than the levels in the controls, following treatment with desalinated seawater for 360 days （P 〈 0.05）. Blood levels of arteriosclerosis-related lipid peroxidation indicators and C-reactive protein （CRP） in the treatment group did not differ from those in the controls. The levels of lipid peroxidation indicators and CRP in rats were not significantly affected by drinking desalinated seawater, and no increase in risk of arteriosclerosis was observed.

Analysis of Passive Solar Desalination Technology Route

Since the world’s first large-scale solar desalination plant was built,there has been no breakthrough in passive solar desalination technology.The reason for this is that the problems of photothermal conversion,evaporation and condensation have not been properly solved.As a hot research topic at present,solar interface evaporation technology is only an improvement of disk solar desalination technology.The solar evaporation technology sets the heating surface,evaporation surface and condensing surface from top to bottom.It has high efficiency of photo-heat conversion,large amount of seawater evaporation and good condensation effect.Some of that heat is recycled,and it is used to heat seawater,which is a disruptive technology.We have seen the development of passive solar desalination technology that Disk solar desalination technology is the starting point,solar interface evaporation technology is the current research hotspot,and solar evaporation technology with overhead heating surface will be the end of the whole process.

Reconfiguration and self-healing integrated Janus electrospinning nanofiber membranes for durable seawater desalination

Janus electrospinning nanofiber membranes have attracted extensive attention in the fields such as solar-driven interfacial desalination,liquid filtration,and waterproof and breathable fabrics.However,the Janus structures suffer from weak interfacial bonding and vulnerability to damage,making the durability and sustainability are highly sought after in real-word applications.Herein,we fabricate the simply reconfigurable and entirely self-healing Janus evaporator by electrospinning polypropylene glycol based polyurethane(PPG@PU)and polydimethylsiloxane based polyurethane-CNTs(PDMS@PU-CNTs)with different wettability,which are both designed based on dynamic Diels–Alder(DA)bond.The interface of the Janus membrane is stitched by the covalent bonds to directly improve the interface adhesion to 22 N·m−1,constructing an integrated evaporator,and thereby achieving a stable desalination rate of 1.34 kg·m−2·h−1 under one sun.Reversible dissociation of DA networks allows the evaporators for self-healing and reconfiguration abilities,after which the photothermal performance is maintained.This is the first work for the crosslinked self-healing polymer to be directly electrospun,achieving the improved interfacial bond and reconfiguration of entire evaporators,which presented promising new design principles and materials for interfacial solar seawater desalination.

Self-Supporting Nanoporous Copper Film with High Porosity and Broadband Light Absorption for Efficient Solar Steam Generation

Solar steam generation(SSG)is a potential technology for freshwater production,which is expected to address the global water shortage problem.Some noble metals with good photothermal conversion performance have received wide concerns in SSG,while high cost limits their practical applications for water purification.Herein,a self-supporting nanoporous copper(NP-Cu)film was fabricated by one-step dealloying of a specially designed Al_(98)Cu_(2)precursor with a dilute solid solution structure.In-situ and ex-situ characterizations were performed to reveal the phase and microstructure evolutions during dealloying.The NP-Cu film shows a unique three-dimensional bicontinuous ligament-channel structure with high porosity(94.8%),multi scale-channels and nanoscale ligaments(24.2±4.4nm),leading to its strong broadband absorption over the 200–2500 nm wavelength More importantly,the NP-Cu film exhibits excellent SSG performance with high evaporation rate,superior efficiency and good stability.The strong desalination ability of NP-Cu also manifests its potential applications in seawater desalination.The related mechanism has been rationalized based upon the nanoporous network,localized surface plasmon resonance effect and hydrophilicity.

Superhydrophilic Polydopamine‑Modified Carbon‑Fiber Membrane with Rapid Seawater‑Transferring Ability for Constructing Efficient Hanging‑Model Evaporator

Solar-driven seawater desalination has attracted much attention for alleviating global freshwater shortage,but the practical application is often limited by complicated fabrication processes,unsatisfactory seawater-transferring and severe salt accu-mulation on the photothermal membranes.To solve these problems,hydrophobic industrial-grade carbon fiber membrane(CFM)with good photoabsorption was surface-modified with polydopamine(PDA)to prepare superhydrophilic CFM@PDA for the construction of efficient hanging-model evaporators without salt accumulation.The coating of PDA on CFM is realized by simple self-polymerization of dopamine,and the as-prepared CFM@PDA exhibits high solar absorption effi-ciency of 96.7%,good photothermal effect and superhydrophilicity.Especially,when CFM@PDA is hanging between two water tanks(one contains seawater and the other is empty)in a flat hanging-model evaporator,it can transport seawater at a high rate(26.35 g/h)which is 3.6 times that(7.28 g/h)of commercial cotton fabric.Under simulated sunlight(1.0 kW m^(-2))irradiation,CFM@PDA shows a high evaporation rate of 1.79 kg m^(-2) h^(-1) with a solar evaporation efficiency of 92.6%.Even if NaCl solution with a high concentration(21.0 wt%)is used for the evaporation,the hanging CFM@PDA can retain a high evaporation rate(~1.80 kg m^(-2) h^(-1))without salt accumulation during the long-time test(8 h),which is significantly better than that of the tradition floating model.Therefore,this study not only demonstrates the simple preparation of super-hydrophilic CFM@PDA,but also promotes the further practical applications of hanging-model evaporators for continuous salt-free desalination.

Solution-processed D-A-π-A-D radicals for highly efficient photothermal conversion

Organic donor-acceptor semiconductors exhibit great potential in photothermal conversion.However,it is still challenging to achieve pure organic materials with broad absorption comparable with inorganic materials such as graphene.Herein,two D-AD type DPA-BT-O4 and NDI-TPA-O4 and three D-A-π-A-D type Th-O4,Th2-O4,and IDT-O4 were readily prepared via two high-yield steps and simple air oxidization.The stability can be attributed to their multiple resonance structures based on the aromatic nitric acid radical mechanism.Compared with the D-A-D radicals,the conjugation extension of the D-A-π-A-D radicals endows them with a narrowed band gap and broad absorption in powder.Interestingly,the IDT-O4 powder with aggregation-induced radical effect exhibits broad absorption between 300 and 2500 nm,which is comparable with graphene and other inorganic materials.Under irradiation of 0.9 W/cm^(2)(808 nm),the temperature of IDT-O4 powder rises to 250℃within 60 s.The water evaporation conversion efficiency of 94.38%and an evaporation rate of 1.365 kg/m^(2)h^(−1)under one sun illumination were achieved.IDT-O4 stands as one of the most efficient photothermal conversion materials among pure organic materials via a rational design strategy.

Nanoporous black silver film with high porosity for efficient solar steam generation

Given the challenges brought by the shortage of freshwater resources,solar water evaporation has been regarded as one of the most promising technologies for harnessing abundant sunlight to harvest clean water from the sea.Nanostructured metals have attracted extensive attention in solar water evaporation due to their localized surface plasmon resonance effect,but highly porous metallic films with high evaporation efficiency are challenging.Herein,a self-supporting black nanoporous silver(NP-Ag)film was fabricated by dealloying of an extremely dilute Al99Ag1 alloy.The choice of the dilute precursor guarantees the formation of the NP-Ag film with high porosity(96.5%)and low density(0.3703 g·cm^(-3),even smaller than the lightest metal lithium).The three-dimensional ligament-channel network structure and the nanoscale(14.6 nm)of ligaments enable the NP-Ag film to exhibit good hydrophilicity and broadband absorption over 200‒2,500 nm.More importantly,the solar evaporator based on the NP-Ag film shows efficient solar steam generation,including the efficiency of 92.6%,the evaporation rate of 1.42 kg·m^(-2)·h^(-1)and good cycling stability under one sun irradiation.Moreover,the NP-Ag film exhibits acceptable seawater desalination property with the ion rejection for Mg^(2+),Ca^(2+),K^(+)and Na^(+)more than 99.3%.Our findings could provide a new idea and inspiration for the design and fabrication of metal-based photothermal films in real solar evaporation applications.

Constructing central hollow cylindrical reduced graphene oxide foams with vertically and radially orientated porous channels for highly efficient solar-driven water evaporation and purification

Although solar steam generation is an eco-friendly approach for desalinating seawater and purifying wastewater,there are still issues on how to improve the efficiency of solar energy utilization and accelerate the water and heat transport inside the solardriven water evaporators.Herein,we design a central hollow cylindrical reduced graphene oxide(RGO)foam with vertically and radially orientated channels as a solar steam generation device for efficient water evaporation and purification.The vertically aligned porous channels accelerate upward transport of water to the top evaporation surface,while the radially aligned porous channels facilitate water transport and heat transfer along the radial directions for fully utilizing the heat accumulated inside the central cylindrical hole of the foam.The central hole of the foam plays a highly positive role in accumulating more heat for accelerating the water evaporation,the newly generated inner sidewall resulted from the central hole can gain extra thermal energy from surrounding environment in the same way as the outer sidewall of the foam due to the surface cooling effect of the water evaporation.As a result,the vertically and radially aligned RGO foam evaporator with central hollow cylinder achieves a high solar steam generation rate of 2.32 kg·m^(−2)·h^(−1)with an exceptional energy conversion efficiency of 120.9%under 1-sun irradiation,superior to the vertically aligned RGO foam without the central hole(1.83 kg·m^(−2)·h^(−1),96.9%)because of the enhanced water and heat transfer inside the porous channels,the efficient utilization of environmental energy.

A cobalt oxide@polydopamine-reduced graphene oxide-based 3D photothermal evaporator for highly efficient solar steam generation

Improving the evaporation rate and energy efficiency of solar steam generation is very important to facilitate real-world applications for clean water production.In this work,Co_(3)O_(4)@polydopamine(PDA)nanoparticles were synthesized and combined with reduced graphene oxide(rGO)to fabricate a new Co_(3)O_(4)@PDA-rGO photothermal aerogel.The obtained pho-tothermal aerogel sheet was thereafter used to prepare both two-dimensional(2D)and three-dimensional(3D)photothermal evaporators for solar steam generation.Due to the excellent light absorption and hydrophilicity of the photothermal aerogel,a high evaporation rate of 1.60 kg·m^(−2)·h^(−1) was achieved for the 2D photothermal evaporator.While for the 3D evaporator,the evaporation rate was dramatically increased to 3.71 kg·m^(−2)·h^(−1) with a corresponding light-to-vapor energy efficiency of 107%.This was attributed to an increased evaporation surface area,decreased energy loss from the top evaporation surface to the environment,and energy gain from the environment on the side evaporation surface.The 3D evaporator also showed excellent practical performance in seawater desalination thus demonstrating great potential for real-world applications.

Optimization of heat source side technical scheme of combined heat and water system based on a coal-fired power plant

Recovering the waste heat(WH)of a power plant can conserve energy and reduce emissions.Scholars have proposed utilizing the WH of power plants in a combined heat and water(CHW)system,which is considered an economical,energy-saving,and environment-friendly way to integrate water and heat supply into long-distance transportation in urban areas of northern China.However,to date,a detailed design of the case on the heat source side of the CHW has not been developed.Therefore,in this study,the heat source side of a CHW system was divided into two cases:a single-generator set and a double-generator set,and both cases were optimized.The parameters of a multi-effect desalination(MED)process were examined;the optimal number of evaporation stages during the MED process was 12,and the optimal heat source temperature during the first stage was 700C.Then,by matching the extraction and exhaust steam flows,the WH of the exhaust steam in the heating season was finally utilized.Further,under each case optimal conditions,energy,exergy,and cost were analyzed.The results showed that the exergy efficiency in the heating season for each case was approximately 50%,whereas that in the non-heating season was approximately 3.5%.The economy and water quality of the single-generator case were better than those of the double-generator case.However,the absorption heat pump required in the single-generator case is difficult to realize because it operates under two working conditions.

A green and efficient strategy facilitates continuous solar-induced steam generation based on tea-assisted synthesis of gold nanoflowers

Developing a highly efficient system for solar steam generation(SSG)using a straightforward and eco-friendly method to harvest freshwater is fascinating but challenging.Here,we stir the mixture of brewed tea and HAuCl4 to prepare Au nanoflowers,possessing broad wavelength light absorption and excellent photothermal effects.After freeze-drying the mixture of Au nanoflowers,cellulose nanocrystals(CNCs),and aqueous polyurethane(PU)emulsion,we obtain three-dimensional(3D)porous structures(CNC-PU-Au)for SSG.The whole process does not involve any sophisticated procedure or produce detrimental byproducts.The evaporation rates are 2.24 kg·m^(−2)·h^(−1) for pure water and 2.18 kg·m^(−2)·h^(−1) for seawater using CNC-PU-Au under one sun.The solar energy conversion efficiency is up to 90.92%under one sun illumination.Besides,CNC-PU-Au shows self-driven salt resistance and durability.In outdoors application for seawater desalination,the maximum evaporation rate can maintain at 2.19 kg·m^(−2)·h^(−1) in spring and 3.42 kg·m^(−2)·h^(−1) in summer.These unique features promise the utility of CNC-PU-Au in the ecofriendly water treatment industry.