Abstract
The following results were obtained in the experiments to improve the treated water quality at a combination system with two reverse osmosis systems, called “Double-pass Reverse Osmosis System”. (1) The installation of degasifier to reduce CO2 gas in raw water, gave a remarkable improvement of product water. (2) H2SO4 and Ca(OH)2 were used as the alternates of HCl and NaOH, respectively, to reduce pH value for preventing scaling and to convert CO2 to HCO3 or CO3 ion. (3) The electrolized cathode water was used instead of injecting alkali reagent such as NaOH for CO2 convertion, and resulted in the reduction of ion increace, which was expected to improve product water quality.
