The assessment of magnetic water treatment on formation calcium scale on reverse osmosis membranes

Abstract

Reverse osmosis is widely used technology for water desalination. The main problem with reverse osmosis is scaling which reduces the flow and selectivity of membranes. Normally, to prevent salt precipitation, chemicals are added to the feed water or water softening is applied. The literature data on the effect of magnetic treatment on the structure and properties of water and dissolved salts showed that there is no consensus among researchers on the mechanism of magnetic field action to prevent calcium deposits formation. The purpose of current work was to study the effect of magnetic water treatment on the rate of calcium carbonate scale formation on reverse osmosis membranes. Scaling tests were carried out on tap water using the spiral wound module with reverse osmosis membranes. Magnetic treatment efficiency was evaluated by comparison of scaling rate values (amount of calcium carbonate scales accumulated in membrane module) determined throughout experiments with and without magnetic device. The results obtained do not confirm the effect of magnetic treatment on calcium carbonate precipitate formation.