A conceptual demonstration and theoretical design of a novel “super-gravity” vacuum flash process for seawater desalination

A holistic review on how artificial intelligence has redefined water treatment and seawater desalination processes

Thermal type seawater desalination with barometric vacuum and solar energy

Both brackish water desalination and seawater desalination processes are well established and in common use around the globe to create new water supply sources. The farther the location of the source water from the ocean or seashore, the lower the salinity (TDS) of the water and the lower the osmotic pressure that needs to be overcome when desalinated water is produced. This is one of the major reasons that brackish desalination is often considered less costly than seawater desalination. A number of project considerations, however, indicate that seawater desalination can be beneficial and more cost-effective than brackish water desalination. To make a fair comparison, we need to properly compare all major aspects of both types of projects to define the best and most appropriate desalination technology. While brackish water has less feed water TDS, it is more challenging to dispose of the produced concentrate. Also, although brackish water desalination needs less energy to overcome osmotic pressure, it usually requires more energy to draw the water from the well than it takes to pump seawater from the open ocean intake. Another factor is that the temperature of the brackish well water may be lower than the temperature of ocean water, giving seawater desalination an advantage in energy demand. In comparing brackish to seawater desalination, these major aspects should be evaluated: (1) Locations of seawater and brackish water plants, relative to the major consumers of the desalinated water, (2) Transportation (pumping and disposal) costs of the feed water and produced water, (3) Potential colocation of a seawater plant with a large industrial user (e.g., power plant) of the seawater for cooling or other purposes, (4) Produced quality of brackish water and seawater desalination in terms of major minerals and emerging contaminants, (5) Sustainability of the water source: capacity and depth of the brackish water wells, as well as the type of soil. (6) Technical and economic aspects of produced concentrate disposal, (7) Permitting process costs for brackish and seawater desalination, and (8) The economics of both brackish and seawater desalination treatment processes: capital costs, operational and maintenance (O&M) costs, lifetime water cost, and total water cost (TWC). This paper discusses the major evaluation criteria and considerations involved in properly comparing the economic and technical aspects of brackish and seawater desalination to determine the more favorable desalination technology for a given desalination project.

Comprehensive analysis of a hybrid FO-NF-RO process for seawater desalination: With an NF-like FO membrane

A novel hybrid forward osmosis - nanofiltration (FO-NF) process for seawater desalination: Draw solution selection and system configuration

Developing bactericidal membranes is of interest to the membrane industry in seawater desalination and other water purification processes. The pivotal step for the fabrication of a high performance...

Incorporating a seawater desalination scheme in the optimal water use in agricultural activities

Economic and Safety Aspects in Nuclear Seawater Desalination

Occurrence, toxicity, and control of halogenated aliphatic and phenolic disinfection byproducts in the chlorinated and chloraminated desalinated water

The role of desalination in bridging the water gap in Jordan

Analyses of static energy conversion systems for small nuclear power plants

Surface-engineered sulfonation of ion-selective nanofiltration membrane with robust scaling resistance for seawater desalination

Hybrid systems in seawater desalination-practical design aspects, status and development perspectives

To improve the performance of Cellulose di-acetate (CDA) based forward osmotic (FO) membrane in sea water desalination process, functionalized multi-walled carbon nano-tubes (MWCNTs) were blended as additives at varied compositions, from 0 to 5 wt%, into the solutions to prepare FO membranes using a classical phase-inversion method. The structure and property of the formed membranes were characterized by Fourier transfer infrared (FTIR) spectroscopy, Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), Transitional Electron Microscopy (TEM), Water Flux and Reverse Solute Flux Tests. It was found that the content of functionalized MWCNTs was an important factor influencing the morphology, porous structures and properties of the blend membranes. SEM, AFM and TEM images of the blend membranes showed that the surface morphology and the cross-sectional morphology changed with the content of functionalized MWCNTs. It is interesting to see that at the presence of functionalized MWCNTs, the surface contact angle and the reverse solute flux of the FO membranes could be greatly improved without significantly affecting the pure water flux. With the addition of only about 1 wt% MWCNTs, the water flux of CDA based FO membrane was increased from 10.5 to 12.5 L/m2h while its reverse solute flux was reduced from 1.8 to below 0.3 mol/m2h. Desalination tests with 3.5 wt% simulated seawater feed solution had shown that the blend membrane with 1 wt% MWCNTs, was 366% higher in water flux and 53% lower in reverse solute flux than those of pure CDA FO membrane. These results suggest that CDA bases FO membranes modified with functionalized MWCNTs could possess good potential to be further developed for practical applications in the sea water desalination processes.

In the sea water desalination process, brine is produced as a byproduct. Brine contains several resources which are various valuable ion materials in high concentration. If the sea water desalination process is integrated with a resource recovery process, a reduction in environmental load and production of valuable resources can be achieved. Mg2+ ion is the second most abundant ion in sea water. However, the development of a Mg2+ ion recovery method is not sufficient. The Mg2+ recovering method in magnesium hydroxide (MH) form from brine has been studied. Brine and bittern are produced when the sea water desalination process is integrated with the resource recovery process. When MH is recovered from concentrated sea water, two kinds of raw resource materials, i.e. brine and bittern, can be considered. However, the MH recovery process using brine as a raw resource material is not compared with the recovery process using bittern. This is because there is almost no fundamental data of MH crystals for process comparison, and MH crystals are produced as ultra-fine particles. Therefore, the purpose of this present study is to obtain the fundamental data for development of the MH recovery process in an integrated process. In particular, the prevention method of ultra-fine MH crystal deposition is investigated, and the yield and crystallinity of MH crystals are compared. It is clear that the yield and crystallinity of MH crystals are strongly dependent on temperature and the kind of raw resource material. These results show a strategy for improvement in process efficiency when MH crystals are recovered from the sea water desalination process.