Studies on Membrane Applications in Water Treatment

Case Studies on Membrane Applications in Water Treatment 

Desalination of seawater is one of the important applications of membrane processes. There are various ways to produce fresh water such as distillation, electrodialysis, membrane distillation, freezing, membrane bioreactor, and reverse osmosis. Among them, distillation is the most used technique, but RO is becoming more popular in the desalination industry. A flow diagram of a single-stage RO system is shown in Fig. 4. 

In order to reduce fouling and protect the membrane, pretreatment must be performed for seawater. A pretreatment system removes suspended sobds and other potential fouling materials. Flocculation agents such as iron chloride or polyelectrolytes are added in order to remove suspended sotids. Chlorine is added to remove bacteria and algae. 

When a membrane-based desalination process is used, seawater is first collected and pumped to the water-treatment plant. Sodium hypochlorite is injected periodically after the intake pumps to prevent biological growth within the water-treatment system. Suspended solids are retained by sand filters or MF. The filtered water is then acidified. 

Case 2 Removal of Salts from Food Processing Water Stream by NF 

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