I want to know the best selection of technology for desalination with low TDS well water (normally below 1000 ppm) and, with consideration of brine and rejects, which system is recommended?
What is your required quality for the desalinated water, if you want to produce soft water (TDS=10-40ppm) RO would be your choice. If you want to have demin water (TDS
A fresnel lens and metal core should desalinate and purify water in polluted wells but have to be aware pesticides and herbicides have boiling points higher than water and can be conveyed with the otherwise pure water. Please email for details. rosjonesenvedu@hotmail.com
The flow rate is 300 m3/day and exact TDS is 480 ppm and target destination is produced water for boiler , right now we have Ion exchange technology and we want revamping that.
For well water, typically there is a concern about water hardness. Then, for TDS 1,000ppm, you will need to use RO since Ion Exchange system will not be viable. Subject to final water quality you need, you may consider 2 pass RO then add in mixed bed exchanger or deionization system to get demineralized water. To know more, you may browse through our website: www.organo.co.jp
Mahmud, the most important consideration for using RO on well water is the temperature of the water. well water is usually low temp. and rejection ratios will be high unless you pre-heat the water. With 55 degreee (f) water the rejection ratio can be as high as 20-1. Tim Shrum
For a TDS of 1000, the most suitable energy efficient and high recovery technology is possibly the capacitive deionisation. Most of the CDI products are using ion selective membranes to desalinate water. However, a new technology which is membrane-free CDI and is 25-40% more energy efficient is being tested here in Stockholm, Sweden and is showing promising results since the water recovery is almost 80 %. The Company website is going to be online in a months time: stockholmwater.se
1000 ppm is normally about the maximum that can be achieved with ion Exchange. Above that, the demin water requested for regeneration may even the capacity of the plant and reduce the net output down to zero.
Hence I believe that RO is the best solution among the two However there are other technologies which are better than RO for such low salinity, like electrodialysis, which I suggest because of lower energy consumption and good quality of the desalinated water.
Dear Mr. Ghasenpour, your question is not very simple to answer because the selection of the best technology will depend on the quality (e.g., TDS) of the target product water quality and content of other compounds such as silica. Overall, if the goal is to produce drinking water, then brackish water RO could still be the best technology. If the water however contains silica over 20 mg/L and does not contain pathogens, elictrodialysis reversal or capacitive deionization may be more attractive coast-wise. Ion exchange will only be viable if you would need to produce high purity water for boiler water applications or other industrial uses.
I agree with the above, Furtheremore, with access to high recovery RO that prevents scaling even under relatively challenging WQ condition, RO majes wven more sense.
it depends however Single Pass RO will be better in the sense low CAPEX and Low OPEX . even for sich low feed TDS.. you can use the reject for any other purpose easily. in addition RO has lesser foot print and fully automation.
ion exchange reject cannot be used and even it's regeneration and other aspects require skilled operator than RO. ion exchange has bigger foot print too.
My recommendation is to go for RO you can easily get