Removal of N-nitrosodimethylamine from waters using physical-chemical techniques

During the 1950s and 1960s, the Rocky Mountain Arsenal (RMA) was leased by the US Air Force for the purpose of producing rocket fuel, namely Aerozine 50, by blending hydrazine and unsymmetrical dimethyl hydrazine (UDMH). A product of the decomposition of UDMH is N-nitrosodimethylamine (NMDA). Bituminous coal granular activated carbon (GAC) systems located at the boundaries of the RMA are not highly effective at removal of NDMA. Modifications to the existing systems by adding additional adsorbents specific to NDMA removal vs construction of new facilities were evaluated. This paper summarizes the results of investigations into alternative adsorption technologies which might be more effective at removal of NDMA than bituminous coal GAC. The results were well described by the Freundlich adsorption isotherm model. Bench-scale isotherm and column studies revealed that a coconut shell GAC and carbonaceous resin were more effective at removal of NDMA than bituminous coal GAC.