30 Containment systems Desalination plants

This issue is very significant for pretreatment systems for seawater desalination plants with open-ocean intakes. Often the source seawater contains small sharp objects (such as shell particles), which can easily puncture the pretreatment membranes and result in a very quick loss of their integrity, unless the damaging particles are removed upstream of the membrane pretreatment system. As discussed previously, to remove sharp seawater particles that can damage the membranes from the source water, the SWRO plant intake system has to incorporate a microscreening system that can remove particles larger than 120 p,m. 

Systems containing fissile or radioactive materials (generic) Power plants used for cogeneration, heat generation or desalination... 

Salt content of the desalinated water depends on the SWRO plant recovery ratio and the quality of the membranes. The product may contain NaCl at a level below 100 mg/L and up to 1000 mg/L. That can be reduced by a second-stage membrane treatment of permeate as explained in the previous sections of this chapter. Using two- or three-stage SWRO systems to remove boron to lower levels will further reduce the sodium chloride salt content as weU. As the water quality is improved, however, the produced water would have very low mineral content (especially calcium hardness) and therefore would be more aggressive and may dissolve matter from the piping system and increase pipe material corrosion rate. 

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