Antiscalant Dosing Formula in Reverse Osmosis Systems

Reverse osmosis antiscalant (scale inhibitor) significantly delay membrane scaling and extend the service life of reverse osmosis membranes. This is why dosing of scale inhibitors is important. The dosage of scale inhibitors must be controlled because adding too much or too little will affect the effectiveness of the scale inhibitors.

Formula for Monthly Usage Calculation

The recommended concentration of scale inhibitor in reverse osmosis systems is generally 3–6 ppm, which means that 3–6 g of scale inhibitor needs to be added for every 1 ton of water entering the reverse osmosis equipment.

W=Q×S×H×30/1000

• W represents the monthly usage quantity (kg)
• Q represents the water flow rate entering the reverse osmosis equipment (m³/h)
• S represents the dosing concentration (3–6 ppm, in g/ton)
• H represents the operating time of the reverse osmosis equipment (hours)
• 1000 is the conversion factor between g and kg

Scale inhibitors for reverse osmosis systems are generally added to the security filter, which is before the precision filter. They are added to the pipeline of the reverse osmosis equipment through the dosing device using a metering pump.