Treatment of chlorides
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Recently, as part of the water quality assessment for the project, it was found that the chloride levels in the water at the site selected are significantly above the acceptable limits. I searched online, and membrane treatment or nanofiltration is used to remove chlorides. However, for an industrial plant, the volume of water in circulation is very large, so this is clearly not an effective approach. Therefore, I would like to ask if there are any suitable new technologies? Or, which additive can be used to avoid the impact of chloride concentration?
Treating chloride ions is challenging. In circulating water, chloride ions are primarily introduced by disinfectants; they may also come from make-up water. Generally, the chloride ion concentration in natural water bodies is low, ranging from a few to several dozen units – not high at all. Even if the water is concentrated several times, the chloride ion level remains low. However, this is not the case when using recycled water derived from wastewater treatment, as the chloride ion concentration is relatively high. After further concentration, it can reach several hundred units, which has a serious corrosive effect on the system. To remove chlorine, technologies such as reverse osmosis membranes and ion exchange membranes can be used; however, one drawback is the high treatment costs. It would be better to use a lower concentration ratio or increase the amount of water added.
Apart from membrane technology, it seems there are no other good processes for desalination. It’s true that it can be diluted though.
There is no economically viable solution for dealing with chlorides in circulating water; the volume of water is too large, so the only option is to use materials of higher quality for pipes, equipment, and heat exchangers in order to cope with this situation