{'fraction_non_alphanumeric': 0.028846153846153848, 'fraction_numerical': 0.01510989010989011, 'mean_word_length': 4.9227642276422765, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Evaluation of removing monovalent and divalent ions of brackish water in Qom Province using membrane processes of nanofiltration, reverse osmosis and hybrid system

The water shortage in the Middle East and North Africa, especially in Iran, and overuse of ground­ water resources, are serious problems in the world. For this reason, the desalination of brackish water is essential for clean water demand. In Iran, Qom Province is one of the areas which faces drought and water shortage, therefore using membrane desalination can be a solution to resolve the water crisis in this area. In this study, the desalination process was performed by nanofiltration (NF), reverse osmosis (RO) and hybrid NF/RO membranes. Then, the percentage of monovalent and divalent ions removal in the three processes; NF, RO, and hybrid NF/RO membranes were compared. This study also used the reverse osmosis system analysis (ROSA) simulation model to find the effect of pressure change on the performance of the three membrane processes and the change in membranes to NF90­4040 and BW 30­4040. The results of the pilot study, software ROSA and comparison of NF, RO, and hybrid NF/RO membrane processes were characterized in terms of water production quality and ion removal by the above two methods. The percent of monovalent and divalent ions in software ROSA were calculated at 91.25% and 99.5%, which is close to 100% and therefore is considered as purified drinking water.