Seawater Desalination 30 m³/day with Pretreatment

Integrated 30 m³/day Seawater Desalination System with Multi-Stage Pretreatment

For this project, Aqua Genesi designed and implemented an integrated water treatment and desalination system with a production capacity of approximately 1,200–1,300 litres per hour, equivalent to approximately 30 m³/day. The installation is based on reverse osmosis technology and was engineered for fully automated operation through a Siemens programmable logic controller, while also providing full manual operating capability when required.

One of the key engineering challenges was the condition of the borehole feed water, which required an enhanced disinfection and pretreatment strategy. The system therefore incorporates two 1,500-litre feed tanks, operating in a cyclic sequence to provide the necessary contact time for effective disinfection before the water proceeds to the next treatment stages.

The feed water is then supplied through a multistage pump controlled by a frequency inverter, maintaining stable pressure while providing smooth and energy-efficient operation. Pretreatment continues through a multilayer anthracite filtration stage for the reduction of turbidity, iron, manganese and suspended matter, followed by activated carbon filtration for chlorine removal before the water reaches the reverse osmosis membranes. 

Additional protection is provided through sequential 10- and 5-micron cartridge filtration, combined with controlled antiscalant dosing to protect the membranes against scaling and maintain system performance. Antiscalant tank level is monitored automatically, with dedicated warning and protection functions incorporated into the control system.

At the heart of the desalination system is a Danfoss APP 3.5 high-pressure pump, coupled to a high-efficiency electric motor and frequency inverter for controlled start-up, equipment protection and optimized operation. Desalination is performed through nine Toray TM810V membranes installed in nine BEL pressure vessels. The membranes are designed for high salt rejection, with nominal salt removal performance of up to 99.8%. 

Product water quality is continuously monitored. If conductivity exceeds the defined operating limits, the water is automatically diverted to drain rather than transferred to the storage tank. A subsequent dolomite treatment stage adjusts pH and enriches the product water with calcium and magnesium.

The installation also incorporates a fully automatic fresh-water flushing system, protecting the membranes and hydraulic circuit after each operating cycle. The same infrastructure can also be used for chemical cleaning whenever required.

Automation forms an integral part of the project. Pressures, flow rates, conductivity and operating status are monitored through the system's touch-screen interface, while operating hours, start cycles, alarms and protection functions are continuously recorded and managed. The installation also provides remote monitoring and control through smart devices, significantly improving operational supervision.

The overall project also included the installation of a suitable 316 stainless-steel borehole pump, together with the required control, protection and water transfer equipment.

The result is an integrated installation in which water abstraction, disinfection, multi-stage pretreatment, desalination, final conditioning and automation operate as one coordinated system.

This project reflects Aqua Genesi's approach to desalination engineering: not simply selecting a reverse osmosis unit, but designing the complete treatment process around the actual characteristics of the feed water and the requirements of the application, with particular emphasis on engineering quality, equipment protection, energy efficiency and long-term reliability.