Fouling effect on Reverse Osmosis (RO) membranes performance in desalination plant

Reverse osmosis (RO) is the most common and widely used desalination method in desalination plants. The operation of RO plants is significantly hindered by RO membrane fouling. This study investigated the impact of operational conditions on RO performance at various levels of fouling. Two types of membranes were used: the SW30ULE-440i membrane from Filmtec and the SW-440R membrane from LG. The performance of the Filmtectec membrane was analyzed using reverse osmosis system analysis (ROSA 9.1), while LG Q-V2.3.2 software assessed the LG membrane. Various feed operating parameters, such as temperature, pressure, salinity, and flow rate, varied for plant operations. By varying these operational feed parameters, the optimal productivity flow rate and salinity were determined for each fouling factor value. The results indicated that fouling had a significant effect on permeate flow rate, salinity, and specific energy consumption (SEC). As the feed salinity changes from 30 to 70 g/l, the permeate salinity and SEC increase exponentially, and the permeate flow rate decreases. When the fouling factor falls from 1 to 0.6, the relative permeate salinity rises by 31.5 % for Filmtec and 126.5 % for LG. While the rate of decrease in permeate flow rate is about 29 % for Filmtec and 33 % for LG. The relative increase in SEC reaches 41 % and 50 % for Filmtec and LG, respectively. This means that the fouling factor has a greater effect on the LG than Filmtec. At high fouling levels, RO productivity can be increased to the intended value by adjusting the feed's pressure and temperature.