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With the social development and scientific and technological progress , the requirements and the amount of the water of life are getting higher and higher , but on land , freshwater resources are limited , therefore , the contradiction between supply and demand of water resources has become increasingly prominent . Desalination is one of the main measures to solve the world water crisis in the future , but the seawater turbidity very high total solute content , sea water hardness is the leading cause of fouling caused by the desalination process , leading desalination cost high energy consumption . Nanofiltration membrane with superior rejection of divalent ions , can effectively remove divalent ion easy scaling of calcium , magnesium and sulfate in seawater desalination to provide more favorable influent water quality . Thus, if nanofiltration membranes in the desalination field of promotion and application , have a profound impact on the development of the desalination industry . The selected TFC-1812-50 reverse osmosis membrane and NF270-1812 nanofiltration membranes , reverse osmosis and nanofiltration desalination performance of select MgSO4, K2SO4, MgCl2, CaCl2, NaCl and KCl six kinds of inorganic salts , investigated into the expected operating pressure , concentration , and the operating time of the apparent retention rate and membrane flux , and on this basis to study the operating pressure , operating time and seawater salinity of seawater desalination performance . Experiments show that the performance of reverse osmosis membranes and nanofiltration membrane stability , can remove seawater reverse osmosis membrane rejection rate of more than 94% , nanofiltration higher interception rate of solution containing divalent ions in sea water softening nanofiltration membrane 8042 - more than 90% and more than 50% of Mg2 and Ca2, significantly reduce the hardness of the seawater desalination process resolves traditionally easy scaling problem of pollution of the ions on the membrane , reducing the costs and energy consumption of desalination .
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