Smoother Hydraulics and Energy Optimization in SWRO Desalination: Lowering SEC and Protecting the Membrane with Hybrid GA-PSO Control

Energy efficiency in reverse osmosis desalination plants has significantly improved over the last few decades thanks to the integration of high-efficiency pumps, sophisticated membranes, and energy recovery devices. However, further reductions in energy consumption are still required to enable wider adoption of this technology. To deal with this challenge, this work employs a hybrid Genetic Algorithm-Particle Swarm Optimization approach in MATLAB/Simulink to enhance the energy efficiency of a high-pressure piston pump driven by a Permanent Magnet Synchronous Motor, which applies pressure to an RO membrane. Under an osmotic pressure of 46 bar and a semi-permeable membrane area of 37.2 m 2 , the results show a transmembrane pressure difference of 61 bar, a permeate flux of 32.1 LMH, and a water recovery rate of 45%. The feed, permeate, and concentrate flow rates satisfy mass conservation, with respective values of 0.75 Kg/s, 0.34 kg/s, and 0.41 kg/s. The PMSM achieves a rotational mechanical speed of 300 rad/s, without overshoot, while torque and electrical stress remain low, resulting in fewer spikes in active/reactive power, and lower Joule losses of 500 W. Without the integration of an energy recovery device, the system shows a specific energy consumption of around 1.6 kWh/m 3 using the hybrid GA-PSO optimization.