Water

The need for clean, potable water has created a range of opportunities to advance innovative technologies aimed at increasing and improving the global supply of affordable water for drinking, sanitary, agricultural, industrial, and energy applications.

SRI has developed and patented several technologies to address water purification, desalination through forward osmosis, and sludge decontamination. Our researchers have also developed new materials and specialized membranes for water desalination systems.

Water purification

SRI is developing a water purification system based on photocatalytic materials, which can use either natural sunlight or artificially generated ultraviolet light to destroy organic contaminants in water through oxidation and which can be gravity fed. This technology is a major enhancement in terms of cost and speed over conventional UV-light-based systems and has other significant advantages over chemical based water purification technologies. The organic contaminants that can be targeted by this technology are generally all organic materials which include bio-organisms such as bacteria and protozoa, chemical toxins, various acidic materials, pharmaceutically active compounds, personal care products, MTBE, and leaks associated with deteriorating infrastructure.

Potential uses for this technology include but are not limited to point-of-use and/or off-grid applications such as systems portable by humans for military and recreational use, solar-driven systems where electrical grid energy is not available, industrial feed water or waste water treatment, and gray water recycling.

Water desalination through forward osmosis
The need for desalinated water is becoming more important throughout the world as the delivery and management of ground or surface water becomes more expensive. SRI has patents, and is doing engineering work, on forward osmosis technology for use in converting salt water into drinkable water. Other technologies that have been commercialized in the past for desalination (e.g. distillation, reverse osmosis) are typically expensive and require considerable energy. Forward osmosis holds the promise to be less expensive and less energy-intensive than conventional technologies. SRI has been working on a variety of forward osmosis methods over the last 10 years.

Wastewater sludge decontamination
SRI has developed methods for treatment and decontamination of waste water and contaminated soils of chlorinated and other hazardous waste materials such as polychlorinated biphenyls (PCBs), pesticides, and solvents. SRI's technologies include assisted hydrothermal oxidation and other techniques using supercritical water oxidation methods. This technology can be used for large municipal-scale systems and for industrial or medical waste site cleanup.

Membrane development for water desalination systems
SRI has a long history of developing specialized membranes for use in energy storage systems and in water treatment systems. For example, in water desalination systems, both forward and reverse osmosis systems rely on the use of a specially designed membrane to keep water with different concentrations of dissolved materials separated, so that water - but not dissolved materials - may flow between the two sides. SRI has developed new materials for and new applications of membrane technology based on different types of coatings, varying levels of porosity, and multiple substrate materials. Similar technology is used in advanced lightweight and high-energy-density battery systems.

For information about our work in related areas, visit SRI's Physical Sciences Division and Engineering and Systems Division.