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.

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.

Multi-effect distillation system for seawater desalination driven by tidal energy and low grade energy

A multi-effect distillation technology for seawater desalination driven by tidal energy and low grade energy is presented.In the system,tidal energy is utilized to supply power instead of coventional electric pumps during the operation,resulting in the decrease of dependence on steady electric power supply and a reduction in the running costs.According to the technological principle,a testing unit is designed and built.The effects of the feed seawater temperature and the heat source temperature on the unit performance are tested and analyzed.The experimental results show that the fresh water output is 27 kg/h when the heating water temperature is 65 ℃ and the absolute pressure is 25 kPa.The experimental and theoretical analysis results indicate that the appropriate heating water temperature is a key factor in ensuring the steady operation of the system.

Effect of Cross-flow Velocity on the Critical Flux of Ceramic Membrane Filtration as a Pre-treatment for Seawater Desalination

Pre-treatment, which supplies a stable, high-quality feed for reverse osmosis （RO） membranes, is a criti- cal step for successful operation in a seawater reverse osmosis plant. In this study, ceramic membrane systems were employed as pre-treatment for seawater desalination. A laboratory experiment was performed to investigate the effect of the cross-flow velocity on the critical flux and consequently to optimize the permeate flux. Then a pilot test was performed to investigate the long-term performance. The result shows that there is no significant effect of the cross-flow velocity on the critical flux when the cross-flow velocity varies in laminar flow region only or in turbulent flow region only, but the effect is distinct when the cross-flow velocity varies in the transition region. The membrane fouling is slight at the permeate flux of 150 L·m^-2·h^-1 and the system is stable, producing a high-quality feed （the turbidity and silt density index are less than 0.1 NTU and 3.0, respectively） for RO to run for 2922.4 h without chemical cleaning. Thus the ceramic membranes are suitable to filtrate seawater as the pre-treatment for RO.

Multi-functional forward osmosis draw solutes for seawater desalination

Forward osmosis(FO), as one of the emerging desalination technologies, has the potential to produce fresh water from a variety of water sources by utilizing the osmotic pressure gradient across a semi-permeable membrane.Draw solution, as an essential component of any FO process, can extract water molecules from seawater or wastewater. An ideal draw solution should meet three essential requirements, namely high osmotic pressure, low reverse flux, and facile regeneration mechanism. The selection of proper draw solutes is especially critical for an energy-efficient FO process since the energy consumption mostly arises from the separation or regeneration of the draw solution. Recently, we developed a few multi-functional FO draw solutes, mainly aiming to enhance the FO water flux and to explore facile re-concentration methods. This review summarizes these draw solutes,including Na^+_- functionalized carbon quantum dots, thermoresponsive copolymers, hydrophilic magnetic nanoparticles, and thermoresponsive magnetic nanoparticles.

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.

Engineering Problems of a New Thermal Seawater Desalination Technology

A new thermal seawater desalination technology was introduced in this paper. The influencing law of temperature difference between fresh water and seawater on heat utilization was disclosed and a performance evaluation theory for the water-heat ratio-based thermal seawater desalination device was established. Engineering problems of the new thermal seawater desalination technology using fuel oil, natural gas, solar energy, nuclear energy and a variety of industrial waste heat sources were analyzed. A seawater desalination device design using waste heat of diesel engine which is applicable to islands and vessels was proposed. Finally, the technical route for comprehensive utilization of seawater resources and solving the water crisis was developed.

Prospect of the Seawater Desalination Technology

This article classifies the seawater desalination technology into four types of hot method, membrane method, electric field method and solvent method. Electric field method and solvent method still remain experimental stage, while hot method and membrane method have been realized in commercialization but are difficult to be promoted. The problem lies in high water-producing cost. It is difficult for membrane method seawater desalination technology to reduce the water-producing cost. The heat utilization efficiency is not high for the current hot method seawater desalination technology and there is large amount of heat lost with the emission of concentrated seawater. The new hot method seawater desalination technology and new solar-powered seawater desalination technology can divide the seawater into fresh water and solid salt without any emission of concentrated seawater so that the heat utilization efficiency can reach theoretical limit to multiply reduce the water-producing cost. They will become the mainstream technology for seawater desalination and can totally eliminate the global water crisis.

A Seawater Desalination Paradigm Utilizing Solar Energy

The scarcity of potable water added more pressure on the Palestinian and is considered obstacles in planning for sustainable development. It is so important to find alternatives that have no adverse effect on the environment and at the same time provide genuine solutions to the available resources. In this paper a new paradigm for desalinating brackish and seawater is introduced. The proposed system is technically descried with size optimization that may cater for providing definite amount of potable water serving small communities. The main driving energy, electrical and thermal, is converted from the all around year available solar radiation.

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.

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.

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.

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.

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.

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.

Eco-Environment Status of the Bohai Bay and the Impact of Coastal Exploitation

With the rapid economic development in the surrounding coastal zone, more and more wastewater has been discharged into the Bohai Bay. And with the scale of coastal exploitation being expanded year by year, the eco-environment of the Bohai Bay has been confronted with great pressure. In this paper, the main problems in the eco-environment of the Bohai Bay were summarized firstly. Red tides occurred more frequently and more seriously; salinity rose in inshore area, the fishery resources degenerated; all the above indicate that the eco-environment of the Bohai Bay is under a severe situation Next, to make a concrete study of the existing status of the Bohai Bay, the eco-environment index system was set up. Then the principal components analytic method and grey relation method were adopted to carry on a comprehensive analysis on the status. The results show that serious pollution of inorganic nitrogen and active phosphate, and poor species diversity are the main presentations of the bad quality of the inshore aquatic eco-environment of the Bohai Bay, which is mainly induced by the massive discharge of pollutant from land and the overexploitation in the surrounding coastal zone. At last, the variations of hydrodynamic characteristics and the pollutant transport caused by coastal exploitations such as reclamation and seawater desalination are analyzed. The results show that reclamation in coastal water not only decreases the tidal prism and weakens the tidal current action, but also influences the pollution distribution in the coastal water. The seawater desalination project would cause tremendous influence to the aquatic eco-environment of the Bohai Bay as the pollutant＇s pulse impact. Much more attention would be paid to the reasonable use of the coastal zone resources and the control of pollution from land-based sources.

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.