Comparison between two conventional pretreatment methods and ultrafilter membrane of sea water desalination by reverse osmosis method
Subject Areas : Environment Pullotion (water and wastewater)
Vida Pesarakloo
1
,
Amir hessam Hassani
2
*
,
Vali Ali Pour
3
,
Amir Hossein Javid
4
1 - Faculty of Natural Resources and Environment, Department of Environmental Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran.
2 - Faculty of Natural Resources and Environment, Department of Environmental Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran. *(Corresponding Author)
3 - Environmental Health Engineering Department, School of Health, Hormozgan University of Medical Sciences, Bandaraabbas, Iran.
4 - Faculty of Natural Resources and Environment, Department of Environmental Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran.
Keywords: Membrane fouling, pretreatment, reverse osmosis, ultrafiltration. ,
Abstract :
Background and Objective: According to the statistics of the World Health Organization regarding the severe shortage of water in many countries of the world, water supply depends on the use of existing resources, and currently, desalination of sea water and oceans is the only solution to supply water for communities that are Water resources are accessible.Desalination of salt water can be done with two thermal and membrane methods, and research has shown that using membrane technology is a more efficient way to solve this crisis economically and environmentally. In this study, a comparison was made on the performance of conventional pre-treatment and membrane pre-treatment before desalination of sea water by reverse osmosis method. The water inlet the reverse osmosis membranes must be of suitable quality in terms of turbidity and other important indicators of membrane fouling.
Material and Methodology: The method used to analyze plans includes technical indicators. In this study, two pretreatment systems were sampled. These examples are: (1) conventional pretreatment (2) UF pretreatment. Based on this, in the pilots used for a period of one year, the water quality in the inlet and outlet sections such as turbidity and SDI 15 were analyzed and the results were discussed for the final evaluation.
Findings: The average SDI15 index of filtrate during the study time provided by the conventional and UF systems were 5.5 and 1.5 respectively. The required level for reverse osmosis should not exceed SDI15 of 5. which was slightly higher than the appropriate level in the conventional purification method, thus the use of a cartridge filter can solve this problem. The average value of turbidity after conventional pre-treatment wad 0.97 NTU and the standard deviation of turbidity for sea water and filtered is 0.14 and 0.09, respectively. The average value of turbidity after ultrafiltration was 0.35 NTU and the standard deviation for seawater and filtered water is 0.26 and 0.10, respectively. There is a significant correlation between temperature and water yield in both filtration methods.
Discussion and Conclusion: From the results obtained from this study, it can be concluded that membrane-based pretreatment is a suitable technological alternative to the conventional method. Membrane-based pretreatment can successfully replace the conventional pretreatment process.