ESB collaborated with Membratec S.A. to replace the existing plant with a reverse osmosis (RO) water treatment facility to ensure an energy-efficient provision of high-purity water. The plant features a modern membrane system to remove contaminants, especially chlorothalonil products. Aiming to minimize the use of chemicals for higher water quality, the designers chose to eliminate the use of antiscalants.
However, removing these chemicals results in a lowered permeate yield from the RO system. Consequently, higher pressure and more energy are required to meet the desired permeate output. To save energy and associated costs, the designers implemented an energy recovery system using the Low-Pressure PX® Pressure Exchanger® (LP PX) from Energy Recovery.
The plant’s final capacity with first phase and second phase will be 1,200 m3/h with an RO system of 600 m3/h resulting in production capacity of 14,400 m3/day of RO permeate, which will be blended with bypassed ultrafiltrated water. The RO is integrated in a complete treatment system (ultrafiltration, reverse osmosis for half of the flow, ozonation, GAC filtration). The first phase of RO includes two PX LP180 units into each train and the fully commissioned plant will have 16 low-pressure PXs installed.
LP PX: How it Works
The LP PX works by transferring the high-pressure energy from the reject stream to the incoming feed flow, thereby reducing the size of the high-pressure pump and increasing the energy efficiency of the reverse osmosis system. Incorporating a low-pressure PX can significantly reduce the specific energy consumption of systems compared to those without any energy recovery device.
Award-Winning BWRO System Design
- This plant is the first in the world to use an RO system to treat surface water without antiscalants, ensuring high-purity water is
returned to the lake.
- The specific energy consumption of the facility’s reverse osmosis stage falls below 0.6 kWh/m3.
- The plant features a patented cleaning system to remove invasive quagga mussels.
