Title: I dentifying technical R&D challenges for clean water production

1. Title: Identifying technical R&D challenges for clean water production

2. What do we want to get out of this? • Define targets (see table on the left?) • Saline to pipe parity • Brackish to pipe parity • Produced water to avoid re-injection? • For defined targets of supplying water fit for purpose from a variety of sources, what are the technical challenges preventing us from reaching a goal (water processing, component/plant cost & maintenance etc.) ? • What promising research points at possible solutions?

3. 2. System Integration Breakout sessions 1. Energy Flexibility Electricity, Fossil, Renewable, Waste Heat Water Sources • Seawater • Surface • Lake • Brackish • Processes • Produced • Extracted 3. Water Purification (including desalination) Parts I and II 4. Post treatment and Concentrate handling Output Water Intake and pre-treatment • Municipal • Industrial • Agricultural Energy Flexibility: This refers to the use of alternate energy sources such as renewable power, concentrated solar power, to provide cost-effective energy for the processes used in water purification. In conventional water purification systems, such sources are yet to be leveraged at scale. Systems Integration: This includes the broad challenge of reducing the cost of water processing by combining technologies and sub-systems in novel ways (to include integration of sensors and controls) for improved energy efficiency, for ability to cope with changing conditions and for integration with renewable power. The specific technologies and sub-systems may be sourced from different applications and industries. Purification: This encompasses the core processes in the “Water Purification System” such as membrane-based water purification. Current state of the art, as one example of purification technology, is Reverse Osmosis which is energy efficient but limited in terms of reliability. New technologies in development include Forward Osmosis/Membrane Distillation (that work in specific ranges of TDS). Novel membranes and cost-effective manufacturing processes can enable new paradigms in Purification. Entirely novel concepts, not based on membranes are also of interest. Non-TDS related impurities are also of interest, e.g. heavy metals, hydro carbons, bio-contaminants etc. Post treatment, transport, and effluent treatment: This category includes the post-processing steps after the purification step. As the overall cost and energy of the water processing system is determined by these steps as well, it is important that there be a closer examination of the costs and technologies to investigate better methods of transport (for example with more efficient pumps) and effluent treatment.

4. Possible Questions Please send your comments/suggestions on the following questions for breakouts: Questions for the breakout sessions (can be further refined): What is the current state of the art/practice with the relevant technology?  Describe the technology in quantitative terms and with respect to relevant metrics such as cost etc. What are the scientific and technical challenges with existing technology? What science/technology needs to be developed (or further developed) to address limitations of current practice? What quantitative targets (technical metrics) are possible in the near term and far term? Discuss possible pathways to address the goals and targets. What are some of the opportunities with a collaborative effort and what capabilities can we leverage from DOE Labs and other organizations? Is Industry willing to cost share in a collaborative partnership with the federal government?