New Polyamide Interfacial Composite Membranes for Reverse Osmosis
DOD-Army Phase II Contract No. DAAD19-03-C-0041
Reverse osmosis water purification units (ROWPUs) are essential to the Army for providing clean water during combat and humanitarian duties. The Army’s ROWPUs are designed to treat any water source encountered in the world, therefore reverse osmosis (RO) membranes must be effective under a wide variety of rigorous feedwater conditions. State-of-the-art polyamide RO membranes used by ROWPUs have low tolerance to disinfectants such as chlorine, a situation which leads to either rapid biofouling or filter element degradation. The objective of the program was to develop a new polyamide membrane that has significantly enhanced resistance to chlorine degradation and biofouling for use by the DoD and the private sector in ROWPUs. Efforts were also made to increase mechanical integrity for intermittent use without failure. The Phase II program focused its efforts on designing, synthesizing, and characterizing new polyamide materials that form semipermeable membranes using standard fabrication procedures. A new family of polyamide materials was discovered and developed with 10–20 times the chlorine tolerance of the industry standard with high flux, high mechanical stability, and good fouling resistance.