Attempt to adsorb N-nitrosamines in solution by use of zeolites

The strong adsorption of zeolite for N-nitrosamines in solution was first r evealed by use of adsorption, and temperature programmed surface reaction ( TPSR) techniques. N-nitrosodimethylamine (NDMA) and N-nitrosopyrrolidine (N PYR) as well as N-nitrosohexamethyleneimine (NHMI) can be adsorbed on zeoli te Y, ZSM-5 and A in the solution of methylene chloride or water, which wil l be helpful for removal of the N-nitrosamines pollution in environmental p rotection. The equilibrium data were fitted to Freundlich-type isotherms, b ut the adsorption capacity of zeolites mainly depended on their pore size, surface area and acid-basic properties. Molecular size of adsorbate and sol ute-solvent interaction also strongly affected the adsorption of N-nitrosam ines on zeolite in solution. The extraordinary adsorption properties of NaA zeolite for N-nitrosamines in aqueous solution is first reported and discu ssed. (C) 2001 Elsevier Science Ltd. All rights reserved.