Reasons for Pretreatment in RO Water Purification System
A water filling machine is equipment that enables you to bottle purified water, mineral water, and other non-carbonated drinks. However, most of the existing water usually contains contaminants such as colloids, bacteria, minerals and other particles that might be harmful for consumption. Also, impurities such as organic substance, dust, sand, and micro-organisms lower the quality of water for drinking.
In many cases, raw water has to go through a purification system to remove these solutes and sometimes minerals. Various specification and standards guarantee the generation of pure and safe water for drinking and industrial use. This includes the reverse osmosis, ultraviolet rays purification and ultrafiltration.
In any of the process, pretreatment is usually an important aspect. The general reasons for pretreatment are filtration, softening, coagulation, pH adjusting, and clarification. Here are the advantages of pretreatment:
Protects the membrane
When pretreatment is done, most of the suspended solids are removed. This protects the membrane from fouling and increases the final water yield during the RO purification. In this case, filtration or contact coagulation should be adopted as most of the suspended solids are of 50ppm or less. Multi-media filter can also be incorporated in pretreatment.
Prevents Membrane Scaling
At times the amounts of carbonates in raw water are very high. Also, at times lime can be added to raw water to make it soft. However, this act increases the turbidity of water that might cause membrane scaling. To prevent scaling, measures such as antiscalant dosing and cation exchange are taken.
Protects the anion exchange resin
During pretreatment, measures such as clarification, coagulation and adding chlorine can be adopted to reduce the organic substance present in raw water. You can also incorporate an active carbon filter to make sure all the organic substances are out. By doing this, you will protect your RO membrane and anion exchange resin in the purification system.
Prevents chlorine from changing RO membrane composition
When chlorine compound reaches the reverse osmosis membrane, it usually affects its composition leading to the uneven purification process. Ensure that you use the active carbon filter to remove chlorine and other related elements.
Removes the micro-organisms
When micro-organisms reproduce and accumulate in the surface of the RO membrane, it causes corrosion and irreversible damage. Pretreatment ensures that these microorganisms and colloids do not reach the RO membrane.
Prevents formation of hydroxide colloid
High concentration of elements such as iron and magnesium enhances formation of hydroxide colloids in the RO membrane. Filtration and aeration device is usually added t remove these elements.
Always ensure that you use the ideal process when purifying water for drinking or industrial use. Also, make sure the water filling machine you use is automated to increase efficiency.