Low Energy Adsorption Technology to Remove Contaminants from Source Water: Demonstration and Evaluation of a Single-use Low Energy Adsorption Process for Arsenic Removal from Groundwater

California faces severe water resource challenges while simultaneously enforcing some of the most stringent and comprehensive water regulations in the United States and around the world. Some 7,600 wells statewide are contaminated, limiting valuable water resources during drought conditions. Contamination treatment and control are often costly and energy consuming. To ensure the health of communities and continued provision of safe drinking water and to prevent well closure, water utilities, municipalities, and engineers must adopt a more energy- and water-efficient strategy to remove contamination, which will, in turn, help to optimize California’s energy structure and reach the state’s energy goals.

The project demonstrated and evaluated a single-use, low-energy adsorption process to remove arsenic, a naturally occurring contaminant, from water. Removal of trace level contaminants such as arsenic is usually cost and energy intensive. The treatment process evaluated used an adsorption media that can effectively take up arsenic, operates under low pressure (low energy), and can be handled and disposed of once saturated. A pilot system installed at the host site operated for approximately 24 months. Water quality parameters and energy data were recorded. The data showed that the system treated on average 1.2 million gallons of water per month during the project. The system treated the source water (with arsenic concentration up to 88 micrograms per liter) to below the regulatory discharge limit (10 micrograms per liter) despite other contaminations in the water. Energy data showed that the system had an energy consumption of about 1.09 kilowatt-hours per 1,000 gallons treated. Compared with data from other treatment processes such as coagulation filtration and reverse osmosis processes, the system could achieve an energy savings between approximately 22 percent and 83 percent.