Removal of ammonia from waste air streams with clinoptilolite tuff in its natural and treated forms
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Removal of ammonia from waste air streams with clinoptilolite tuff in its natural and treated forms Karel Ciahotn´y · Lenka Melenov´a · Hana Jirglov´a · Olga Pachtov´a · Milan Koˇciˇr´ık · Mladen Ei´c
Received: 21 June 2005 / Revised: 8 September 2006 / Accepted: 11 September 2006 C Springer Science + Business Media, LLC 2006
Abstract Natural and impregnated clinoptilolite tuffs were studied to assess their potential to remove ammonia from air and, in a subsequent application, to use the spent adsorbent as a fertilizer. H2 SO4 , H3 PO4 and HNO3 , as agents containing important plant nutrients compatible with soil, were selected for impregnation to enhance sorption capacity of the natural clinoptilolite tuffs for ammonia removal. Sorbents were characterized using N2 adsorption isotherms at 77 K, X-ray analysis and high pressure mercury porosimetry. Ammonia breakthrough curves on fixed beds of sorbent were determined using appropriate NH3 and H2 O input concentrations, flow rates and temperatures similar to the conditions in animal breeding farms. Impregnated clinoptilolite tuffs showed adsorption capacities comparable to SSP-4, an activated carbon that is commercially used for NH3 removal. Impregnations with H2 SO4 and HNO3 are particularly important, since such modified adsorbents exhibit relatively high breakthrough capacities, thus rendering them potentially useK. Ciahotn´y . L. Melenov´a Institute of Chemical Technology, Prague, Czech Republic H. Jirglova . O. Pachtov´a . M. Koˇciˇr´ık J. Heyrovsky Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic M. Ei´c () Department of Chemical Engineering, University of New Brunswick, P.O. Box 4400, Fredericton, N.B., Canada E3B5A3 e-mail: [email protected]
ful for practical applications in controlling ammonia emissions. The main contribution to the sorption capacity enhancement on impregnated clinoptilolite tuff samples seems to be due to the chemical reaction of ammonia with acids remaining in the macro- and mesopores. Keywords Clinoptilolite tuffs . Ammonia . Adsorption . Impregnation
Introduction Ammonia is a frequent air pollutant in the atmosphere. The worldwide emissions of ammonia have been estimated annually at 25 to 35 mil t. Only 1 to 2 mil t/year originates from natural sources (Bottger et al., 2001). The bulk of ammonia emitted to the atmosphere results from anthropogenic activities (Kapahi and Gross, 1995). The most significant source of ammonia pollution, among anthropogenic sources, originates from agricultural production. In addition, ammonia is also an odour nuisance in the proximity of animal breeding farms (Paul, 1998). On the other hand, ammonium nitrate is one of the most widely used fertilisers in agriculture. Therefore, there is a lasting interest to search for ways how to utilize ammonia from animal breeding in crop farming. A feasible way to remove ammonia from air can be carried out by employing a sorption process. Relevant agrochemical tests can provid evidence Springer
220 Table 1 Clinoptilolite t
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