NF Membranes Stable in Extreme pH Conditions

Koch also commercializes SelRO membranes especially suitable for extreme pH conditions. Some of them are listed in Tab. 4.5. 

Such membranes have been applied in the separation of heavy metals from acids and highly alkaline solutions, and in the recovery of alkaline solutions used in cleaning processes. Desal nanofiltration membranes commercialized by GE Osmonics can also work at very low pH levels. They have been used to recover heavy metals and clarify 35% sulfuric acid feed streams or 25% phosphoric acid streams. They have also been applied to permeate boric acid and reject radionuclides at a nuclear power station. Somicon/Nitto Denko announces nanofiltration membranes (NTR-7410, 7430 and 7450 HG) for pH range 1-12, temperatures up to 90 °C and a maximum pressure of 50 bar [37]. 

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