News World Water Day 2022 Research Highlight: Improving groundwater desalination devices
Amos Winter of Mechanical Engineering is working to make reverse osmosis systems for brackish groundwater more affordable and sustainable.
Carolyn Blais, J-WAFS March 22, 2022
Regions around the world that don’t have public water infrastructure or access to safe and abundant supplies of freshwater often rely on small-scale, decentralized brackish groundwater desalination devices that use reverse osmosis (BWRO). Unfortunately, these systems can typically only recover up to ~50% of the input feed as drinking water, dissipating much of the input power by throttling the brine stream. This makes these units extremely energy-intensive, and therefore both expensive to operate and environmentally unsustainable.
Energy-recovery devices (ERDs) are designed specifically to recapture hydraulic power in the brine stream and lower energy consumption of the reverse osmosis process, but most of the current ERDs are meant for seawater, not brackish groundwater.
With the support of a 2021 J-WAFS seed grant, Amos Winter, the Ratan N. Tata Career Development Professor in mechanical engineering, is testing an ERD made from sliding vane pumps to improve affordability, energy efficiency, and ease of use in groundwater desalination. Though still in the early stages, Winter and his team have:
- Identified that a balanced vane pump architecture can provide high volumetric efficiency and is a promising option for reducing friction at high operation pressures. These kinds of pumps are also inexpensive and reliable
- Predicted that their proposed sliding vane ERD device will lower power consumption for 0.5-2 m3/h BWRO desalination systems by 60-35%, respectively