Removal of N-nitrosodimethylamine from water by modified activated carbons
Kun Zhang · Carbon Techniques · 2010
In order to eliminate water pollution, the adsorption and relative mechanism of toxic N-nitrosodimethylamine(NDMA) from water by commercially wood and coconut shell activated carbons was studied. The N2 adsorption/desorption, infrared spectra, Boehm titration and DNMA adsorption isotherms were utilized to investigated the influences of modification on the porous structures, surface properties and NDMA adsorption. It was observed that NDMA was preferentially adsorbed in micropores, and activated carbons possessed better adsorption capacity than zeolites. The adsorption behavior is not only correlated with porous structures, but also significantly influenced by surface properties. Water molecules would take most adsorption sites on unmodified activated carbon due to selective adsorption. Simultaneously, NDMA is adsorbed with polar nitrosamine end. After modification, hydrophobic surface of activated carbon would be more likely adsorb NDMA with nonpolar methyl ends, presenting great improvement of capacity due to the less adsorption of water. By the way, the ketone and aldehyde structures on surface would also prefer to get more NDMA adsorption.