Capturing Nitrosamines by Zeolite MCM-22: Effect of Zeolite Structure and Morphology on Adsorption

The activity of zeolite MCM-22 in trapping nitrosamines, a class of well-known carcinogenic environmental pollutants, is reported in this article for the first time. MCM-22 possesses a set of unique porous structures and morphologies, making it possible to trap both volatile nitrosamines and bulky tobacco specific nitrosamines. Liquid adsorption and instantaneous gaseous adsorption methods have been employed to study the impact of morphology on MCM-22's ability in adsorbing nitrosamines in both gaseous and liquid media. As-synthesized MCM-22 was subjected to different treatments to induce morphological changes. SEM revealed a special rose-like appearance. The effects of these morphological modifications on MCM-22's adsorption capacities was studied and compared to NaY and NaZSM-5. The results obtained seem to suggest that enhanced collision probability between adsorbate and adsorbent may have an important role to play for MCM-22. Furthermore, the treatments created mesopores in MCM-22 that enhance mass transport within its hierarchical structure.