Article

Advantages of the appropriate selection of reverse osmosis membranes in desalination plants with open intake

January 2001

Authors:

Aldo Muñoz Elguera

Universidad de Las Palmas de Gran Canaria

Antonio gomez gotor

Universidad de Las Palmas de Gran Canaria

Sebastián O. Pérez Báez

Universidad de Las Palmas de Gran Canaria

It is hoped to make it sufficiently clear with this article that it is of fundamental importance that the reverse osmosis membranes and the conditions under which they will operate be appropriately selected. It is obvious that this choice must be made primarily in function of the quality of the water that will be processed in the water treatment plant (for which reason it is of vital importance that a detailed study and careful characterisation of this water be carried out previously). This article reports the highly encouraging results achieved with Cellulose Tri-acetate membranes in a singular "Hollow fibre" configuration, known commercially as Hollosep HM 10255FI (of Japanese manufacture), which were evaluated in parallel with LP3 potabilisation membranes that process sea water collected using an open intake system with high levels of microbiological pollution.

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Article

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Raimund Bartz

Reverse Osmosis as a method of seawater desalination has received an apparent impetus in recent years. In its initial phase, Reverse Osmosis (RO) was prevailingly applied in desalination equipment for low to medium salinity well water with some degree of purity due to the natural subsoil filtration. The change to surface water treatment then posed tougher pretreatment requirements mainly in ... [Show full abstract] conjunction with the increased colloidal fouling of the membrane surface which significantly reduces permeate flux and quality. In the worst case, the deposits are irreversible and cannot be eliminated by the available membrane cleaning methods so that the membrane will be destroyed eventually. Therefore, a method for elimination of the fouling constituents was examined, that would favourably combine low investment and operating costs with very high flexibility and efficiency.

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Article

Molecular dynamics simulation of seawater reverse osmosis desalination using carbon nanotube membran...

January 2016 · Desalination and Water Treatment

Reverse osmosis (RO) desalination of 35,000 ppm seawater consisting of sodium and chlorine ions with water was simulated using molecular dynamics. In this study, RO simulations were performed at different pressures using carbon nanotube (CNT) membranes having varying pore diameters (8–14 Å). Results showed that a CNT membrane allowed high water fluxes because of the presence of a low energy ... [Show full abstract] barrier for water–carbon interactions, with continuous and ordered water chains observed inside the CNTs. The investigations into the ion rejection capability of CNT membranes revealed that (6, 6) CNTs could provide high rejection rates (>95%). The rejection of ions was mainly due to the presence of a high energy barrier caused by removing the hydrating water molecules necessary for ions to pass through the narrow CNT pore. The desalination performance of (6, 6) CNT membranes and conventional polymeric membranes was then compared. It was found that CNT membranes have a higher normalized flux and comparable ion rejection, indicating their feasibility for effective seawater desalination. Overall, this study demonstrated the usefulness of molecular dynamics in investigating membrane processes and its potential role in improving desalination performance.