Sustainable water purification using Peltier-based thermoelectric cooling for reverse osmosis systems achieving clean water and sanitation

This work discusses the design of an automated smart water-cooling system to prevent thermal damage to reverse osmosis (RO) membranes caused by elevated inlet water temperatures above 45°C. The system integrates six Peltier modules (TEC1-12706) with a custom-designed aluminium heat exchanger housing a 4.5-metre copper coil. An Arduino nano-based control system enables real-time temperature monitoring and automated regulation, utilising DS18B20 temperature sensors, solenoid valves and an OLED display interface. The system demonstrates strong cooling performance, reducing inlet water temperature to 25°C at the outlet when the cooling medium is maintained at 20°C. The automated cycling mode sustains outlet temperatures below 35°C, thereby extending RO membrane lifespan and enhancing overall system efficiency. With a total cooling power of 432 W and temperature-based automation, the solution is suitable for both industrial and domestic RO applications. This paper supports the efficacy of incorporating thermoelectric cooling with smart automation to enable solid thermal control in water purification systems. This promotes SDG goal 6 that affords clean water and salination.