The salinity rejection percent was measured as 50.21%; 72.82 and 78.65% using NF, RO, and hybrid processes, respectively. Salinity reduction by Luna 100GPD, domestic fresh water device, using every three processes led to drinkable water. Results showed that rejection percent was higher in hybrid rather than RO and NF processes. During Nanofiltration and Reverse Osmosis processes, rejection percent was closely similar for TDS and EC parameters. In hybrid process, also, it was similar which declare that TDS and EC parameters are related to each other closely, as pointed out in a book entitled “Standard Methods for the Examination of Water and Wastewater, 2012” [29, 30]. Meanwhile, Salinity rejection percent was shown to be similar to TDS rejection percent, to some extent, which represents a direct relationship between salinity and TDS. In a research done by EPA, at 2015, this relationship between TDS and salinity parameters was noted [31]. Rejection of monovalent ions, such as Na+1 and Cl¯1 happens rarely in Nanofiltration and more usually in Reverse osmosis process. So, these mentioned ions are removed better in RO process rather than NF. However, rejection percent of Na+1 and Cl−1 using hybrid process is the best, in comparison with all two previous processes. Filmtec Company, in 2005, demonstrated that in Reverse Osmosis membrane, salinity, and TDS, as well as Monovalent ions parameters are removed better, compared to Nanofiltration membrane [26, 32]. Due to higher pressure in ROSA model, rejection percent of ions and studied parameters has been augmented regard to laboratory results. Consequently, higher pressure influences on concentration reduction and rejection percent of parameters, which leads to efficiency improvement of the membrane and produced water. Overall, in the hybrid process, difference degree of ions and parameters rejection percent in RO process was determined less than NF, and vice versa. Therefore, Nanofiltration process is more suitable to be applied as pre-treatment. To improve the results accuracy, findings and results of the present study have been compared with the other studies, carried out regarding the performance of NF, RO, and hybrid processes, elsewhere. Atab et al., [33] investigated a research entitled “Effect of desalination using Reverse Osmosis to produce Fresh water from brackish water: Case study: Naseriyeh River, located in Iraq”. They reported that augmenting the pressure from 25 bar to 63 bar, rejection percent of TDS reached to 99.8%. During the present study, increasing the pressure from 5 bar to 13.8 bar (in ROSA software model), rejection percent of Total dissolved solids changed to 99.2%, which is closely similar to Atab study [33, 34]. Naidu et al., [20], carried out a paper entitled” The comparison between Nanofiltartion and Reverse osmosis processes using Vadodara membrane, made in India, to produce healthy drinking water from groundwater”. The authors declared that rejection percent of Cl−1 ion, during %bar pressure was 65 and 72%, using NF and RO processes, respectively. In addition, rejection percent of TDS was 65 and 95%, in NF and RO processes, respectively. However, in the present study, Cl¯1 rejection percent was 21.1% in NF and 43.08% in RO process. Also, TDS rejection percent was measured as 43.41 and 60.26%, in NF and Ro processes, respectively. Due to use of different membranes in Naidu study, compared to the present study, results of rejection percent is different, which has influenced on mentioned parameters and ions rejection [20]. A research entitled “Desalination of offshore waters using hybrid (combined of Nanofiltration and Reverse osmosis) process, in Shanghai, China has been carried out in sciences Academy of Shanghai and laboratory of Marine Protection Technology by (Zhou et al., [19]). They reported that rejection percent of Total Dissolved Solids was 76.2% in the hybrid process, which is relatively similar to the present study, measured as 76.52% [19]. Another research was done by Kaya et al., [35] regarding treatment and desalination of offshore waters of Ezmir using Membrane processes, applying Nanofiltration membrane as reverse Osmosis pretreatment under 30 and 40 bar pressures. The authors understood that average rejection percent of salinity, TDS, EC and Na and Cl ions in hybrid process was augmented from 30 bar to 40 bar, under higher pressure. Similarly, throughout the present study, increasing the pressure from 5 bar to 13 bar using ROSA software model, rejection percent of studied parameters and ions were also augmented [35, 36]. In Arabia, at (2013), Ben-Meriem et al., investigated “desalination using Nanofiltration and reverse osmosis processes, as well as combined with two membranes in hybrid”. They measured salinity in NF, RO and hybrid process as 54.2%, 74.7%, and 83.3%, respectively. Thru the present study, also, rejection percent was reported 50.21 and 72.82, using NF and RO processes, respectively, which is seemed to be highly similar to Ben-Merrim study. Moreover, in a comparison, drawn between rejection of Na+1 and Cl−1, it has been demonstrated that rejection percent of Na+1 was higher than Cl−1 in both NF and RO processes. Similar results have been reported in the current study, within both membranes, alike to Ben-Meriem study [37]. Abhang et al., [38] studied the reduction of ions using Nanofiltration and Reverse osmosis process, in Puma University, India. They reported salinity rejection percent in both NF up to 50%, and 70-90 in RO processes. This study, measured salinity rejection percent using NF and RO as 50.21 and 72.82, respectively, closely similar to [38, 39]. In other hand, (Altaee, [21]) investigated water treatment with divers concentration using two Reverse Osmosis membranes throughout Eastern-Mediterranean. To do this, applied pressure and membrane kind were similar to pressure and membrane applied to ROSA model. Results showed that rejection percent of Na+1 and Cl−1, and Total dissolved Solids using RO membranes, was not significantly different from ROSA model. In the present study, due to higher pressure rather than software ROSA model, there reported some differences in rejection percent of Na+1 and Cl−1and TDS in Laboratory method. The main reason for equalities in results of Laboratory and software ROSA models was similar conditions of pressure and RO in both methods [21].
In Iran others studies have done about performance of RO that was able to decrease EC around range of 81.98%. Also another study declared that with increasing operation pressure removal of materials in water were increased [40, 41]. Other Researches of performance nanofiltration in Iran have done and revealed that NF membranes could decrease TDS in permeable very well if the concentration TDS in row water is around 3000 mg/L. Also Ions could be removed by applying nano filtration [42, 43]. In this research result showed that by increasing pressure in ROSA simulation the removal of parameters increased too and the TDS is in range of 3000 mg/lit could remove well and Ions by three methods of desalination.