Pre-treatment is a critical step in protecting RO and NF membranes. With the spiral wound design of these membranes, backpulsing with water or air agitation is not possible, the system is very prone to fouling. This can result to significant loss of production capacity, pre-treatment is essential for optimal system performance.

1. Screening of Solids: Removing solids from feedwater is essential to prevent membrane fouling and biological growth. Proper screening reduces the risk of damage to high-pressure pump components and smooth operation.

2. Cartridge Filtration: Uses string-wound polypropylene filters to remove particles between 1 – 5 micrometers, minimizing fouling risk and protecting downstream components.

3. Biocide Dosing and Chlorine Deactivation: Oxidizing biocides (chlorine) is dosed to kill bacteria, then bisulfite is dosed to neutralize chlorine to prevent damage to thin-film composite membranes. Biofouling inhibitors are used to prevent slime formation without killing bacteria.

4. pH Adjustment: Acid dosing keeps carbonates in their soluble form, preventing scale formation. Langelier Saturation Index is used to estimate scaling tendencies, to have precise pH control to avoid scaling.

5. Antiscalants: Antiscalants prevents formation of various scales such as carbonates, phosphates, sulfates and fluorides. They also disperses colloids and metal oxides and specialized products can inhibit silica formation for total scale prevention.

1. Stabilization: Lime or caustic soda is added to adjust the pH to 6.8 to 8.1. This prevents corrosion of concrete or cement-lined surfaces and supports disinfection.

2. Disinfection: Disinfection methods are used to kill bacteria, protozoa, and viruses that bypass the desalination process. This can be done through:

At ADVANCED Equipment and Services we know the importance of total pre and post treatment for RO and NF systems. Our proven solutions protect and optimize your water treatment systems.