I-Corps: Water Treatment using Electrically Regenerated Ion-exchange

University Of California-Berkeley, Berkeley CA

Investigators

Abstract

The broader impact/commercial potential of this I-Corps project is providing an affordable and effective means to produce freshwater supplies from brackish water sources. Freshwater shortages have pushed many communities to increasingly rely on groundwater supplies. Several hundred million people worldwide already experience serious water-stress, and their numbers are expected to increase as freshwater availability declines owing to increasing demand. While available fresh groundwater aquifers are limited, there exist considerable amounts of low-to-intermediate salinity brackish groundwater sources that remain unused. Unfortunately, existing desalination technologies are either too energy intensive, have low water recovery rates, or are prohibitively expensive. There is a significant need and commercial opportunity for new technologies that can efficiently convert brackish aquifers into viable freshwater supplies. This project allows for the development of a robust, low cost, energy efficient brackish water desalination technology with potential use beyond drinking water treatment, including food processing, agriculture, and other industrial applications. This I-Corps project will evaluate the commercialization potential of a new technology that will potentially lower the cost of brackish water treatment by reducing the capital, operation and maintenance, and waste management costs compared to existing alternatives. The lower capital cost is achieved by using novel composite electrode materials developed using inexpensive and industrially-scaled precursors. The reduction in operation and maintenance costs are benefits from realizing unique operating modes made possible by the novel electrodes. The new operating modes also eliminate need for harsh chemicals, and instead use low-voltage electricity to regenerate the electrodes after they have captured the dissolved salts from the water being treated. The regeneration leads to a reject stream of concentrated brine, while the adsorption leads to a stream of treated water that is fresh (less saline than the inlet water). The higher water recovery rates in this system minimize the amount of waste generated, subsequently allowing for cost savings in waste management.