Removing hardness forming and heavy metal ions from water - by treatment with strong acid cation exchanger in sodium form followed by reverse osmosis

摘要

Process for treating liqs., esp. water, in ion exchangers which for the removal of the hardness-forming ions Ca, Mg, Sr and Ba and all heavy metals are connected in series with a further processing stage of reverse osmosis, whereby a strong acid cation exchanger is used which is converted into the Na form by treatment with acid and then with the effluent water stream from the downstream reverse osmosis process. USE/ADVANTAGE - The process allows hardness forming ions to be removed from the water so that no deposits are formed on the reverse osmosis membrane without the necessity for adding stabilising chemicals to the water, whilst regeneration of the ion exchanger is accomplished without producing an effluent water contg. large amts. of NaCo, which could cause a disposal problem with large scale appts..