The effect of HCl and H2SO4 injection to reverse osmosis on TDS and LSI for reducing fouling

Abstract

Due to the quality of the water entering the water purifiers, sometimes the amount of solutes and hardness in the water is so high that after a short time, these systems become clogged or full. To solve this problem. Several methods have been proposed in this study, acid injection and its effect on reverse osmosis system by wave software have been investigated. To ensure the condition and accuracy of the incoming water, the necessary tests were performed through the laboratory and the condition of the water and the number of ions and its salts were reported. By injecting acid into the inlet water, the pH value was reduced from 7.58, which is the normal pH of the water, to 5 by micrograph in 0.2 intervals, and after examination, the following results were obtained: With decreasing pH, the LSI number has a suitable decrease, so that at pH 6.1 and lower, the LSI number is negative and this indicates the lack of premature fouling. However, with this reduction, the acidic property of the treated water increases and the possibility of chemical corrosion of the industrial equipment used increases, on the other hand, by injecting acid and lowering the pH, the amount of TDS increased, which should be tried in different ways to minimize this amount. In comparison between injections of two acids performed under the same conditions, the amount of TDS at the time of H2SO4 injection at the pH limit was 10% less than the time of HCl injection.

Keywords

• salt rejection
• reverse osmosis
• desalination
• fouling
• brakish water
• acid