Tag: Reverse Osmosis
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Desalination using forward osmosis with nanofiltration membranes
Forward osmosis (FO) is an emerging membrane technology, often used for desalination. Like reverse osmosis (RO), FO uses a semi-permeable membrane to separate water from dissolved solutes. The semi-permeable membrane acts as a barrier that allows water to pass through while blocking salts. Generally, any dense, non-porous, selectively permeable material can be used as a…
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Advantages of Polyethersulfone (PESU) membranes for pretreatment for SWRO applications
Membrane pretreatment for large-scale seawater desalination has grown rapidly in the last few years. Existing examples seem to show that the additional cost can be more than recouped in reduced chemical costs alone, but there are also environmental advantages. This article is the first of two discussing the advantages of polyethersulfone (PESU) membranes for filtration…
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Gold Coast’s twin intake/outfall tunnels save space and environment
A key part of the anti-drought strategy in Queensland, Australia, has been the construction of a 125,000 m³/d seawater reverse-osmosis desalination plant, located at Tugun on the Gold Coast, due to start producing water in November 2008. This plant will supply up to 20% of the average demand for the Brisbane/Gold Coast Region. The Gold…
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Large Diameter RO Desalination Elements
In recent years, increasing the diameter of spiral elements has been studied as a method of lowering the cost of membrane treatment. It has been shown that the installed cost of a reverse osmosis (RO) plant can be reduced by up to 27% using larger diameter elements.Large diameter elements provide savings in footprint and building…
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Antiscalant removes need for acid in wastewater RO
Field trials of a new scale-inhibiting chemical for use with reverse-osmosis membranes in wastewater reuse plants show that, at a low dose rate, it can increase the solubility of calcium phosphate by over one hundred times, obviating the need for using dangerous and costly acid. Current design practices for large effluent reuse projects are focused…
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Experience helps boost production and stability at Ras Abu Jarjur
Improving production with reduced expenditure could be the main targets of any desalination facility around the world. Such feats are being methodically achieved at Ras Abu Jarjur reverse-osmosis (RO) plant in Bahrain as a result of a series of improvements. Of the many available desalination techniques, RO was seen from the earliest days as a…
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Leveraging nanotechnology for next generation seawater desalination
NanoH2O advanced membranes for reverse osmosis (RO) desalination represent a new material that enhances current polymer-based membranes with the benefits of nanotechnology. These nanocomposite RO membranes represent a step-change in productivity through improved permeability while maintaining requisite salt and contaminant rejection. Since the original publication of this concept, further development and optimization of this membrane…
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Combining Forward Osmosis with Reverse Osmosis
A combination of forward osmosis with reverse osmosis could facilitate the treatment of some high fouling wastewaters. The system uses brine to draw water from the wastewater without high pressure or turbulence. Key element is the membrane’s ability to allow rapid passage of water without much internal concentration polarization. The diluted draw solution can then…
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Perth provides world desalination sustainability model
As the USA finally starts its second large SWRO plant at Carlsbad, Australia is already into a second generation, with contracts let for the Southern Seawater desalination plant, the second to serve the Perth region. The author has for many years been a strong advocate of desalination and has promoted the technology around the world.…
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Trekkopje SWRO opened at Namibian uranium mine
The 55,000 m /d Trekkopje seawater desalination plant in Nambia was opened on 16 April 2010 in the presence of Namibia’s minister of agriculture, water and forestry, John Mutorwa, and former president, Same Nujom. Designed and constructed by Keyplan, a South African specialist water treatment subsidiary of the Aveng Group, the Trekkopje seawater reverse-osmosis plant,…