Seawater Desalination Using a Hybrid Ultrafiltration-Forward Osmosis – Reverse Osmosis Processes Utilizing Resilience Cities on Coastal Shorelines Mitigating with Water Crisis”
Limitation of freshwater resources in Egypt leads the research efforts to look for other water resources to cover the shortage in water demand required for several life aspects. Also, employing low-quality treated wastewater is considered a critical issue due to the negative effect of this type of water on the surrounding environment. Therefore, the need for a technical solution to reuse urban wastewater is a must, especially in the Egyptian community. The scientific collaboration along with planners should reach effective tools to use affordable efficient techniques for wastewater reuse. So, the combination of Forward Osmosis (FO) and Reverse Osmosis (RO) operations with a proper pre-treatment technology such as ceramic ultrafiltration is seemed to be an effective way to apply proper seawater desalination with low operating costs and energy. Forward osmosis was employed to dilute the high saline seawater by using treated wastewater as a feed solution, then using the dilute draw solution as a feed solution in the reverse osmosis operation to reduce the salinity below limitations to reuse the permeate for irrigation purposes. Two stages of desalination were performed, the first stage was to use the FO process to dilute seawater and the second stage was to use the FO process to dilute the rejected water produced from the RO process by the concentrated wastewater remained from the first FO stage. The results showed that the first FO stage was successful in decreasing the total dissolved solids (TDS) of the draw solution from 32000 ppm to 10222 ppm then RO process was effective in minimizing the feed solution salinity from 10222 ppm to 1400 ppm that is permeable to reuse it for irrigation of different crops such as Barley. This water can also be used to irrigate green areas in cities to reduce water consumption and achieve sustainability, which has become a basic requirement in light of the challenges of climate change and its impact on water scarcity. As well could be used to facilitate the reuse of Sea Level Rise excessive water in new means of mitigations and adaptations as green sand du es reconstruction on coastal lines. That technique will facilitate the city’s resilience in face of the impact of climate change.