Purification and reduction of Golpayegan water hardness by modified natural zeolite

Water purification, particularly the reduction of water hardness, is a significant concern in various regions of Iran, especially in Golpayegan. Due to the high costs of large-scale treatment facilities, natural zeolites—abundant and inexpensive in areas such as Semnan province—offer a promising alternative. This study investigates the effectiveness of different modification methods of clinoptilolite zeolite in reducing water hardness. Initially, the zeolite was washed with a ۱۰:۱ solution of distilled water and ۳۷% hydrochloric acid to remove impurities. Four modified forms of zeolite were prepared: (۱) acid-washed only, (۲) acid-washed then milled using a planetary ball mill, (۳) milled then acid-washed, and (۴) acid-washed and sieved to obtain ۲۵۰-micron particles. These samples were used in filtration systems to treat hard water from Golpayegan, which initially had a hardness of ۳۷۵ ppm as measured by TDS meter. Post-filtration results showed water hardness levels of ۳۱۷ ppm, ۲۶۵ ppm, ۴۵۶ ppm, and ۱۹۴ ppm, respectively. The sieved zeolite demonstrated the highest efficiency in hardness reduction, attributed to smaller particle size and minimal processing stress.

کلیدواژه ها:

Natural zeolite ، acid washing ، water hardness ، Purification ، Clinoptilolite