EFFECT OF CHEMICAL MODIFICATION OF HYDROXYAPATITE/ZEOLITE COMPOSITE ON MALODORS ADSORPTION BEHAVIOR

Abstract

: Hydroxyapatite (HAp)/zeolite composite (HZc) was prepared by a simple immersion method, and it was then modified with Cu 2+ and 3-aminoplopyltriethoxysilane (APES) to produce a novel adsorbent for unpleasant odors such as NH 3 , H 2 S and CH 3 CHO gases. The obtained materials were characterized by SEM-EDS, XRD, FT-IR, TG-DTA and ninhydrin reaction test. Nano-sized order HAp was observed distributed on zeolite for HZc, and modification of HZc with Cu 2+ and APES maintained the original framework structure of HZc. Introduced amount of Cu 2+ and APES after the modification was 3.6 mol% and 12.6 mg·g -1 , respectively. The adsorption ability evaluated via a gas bag-detection tube method showed that Cu 2+ -modified HZc increased NH 3 and H 2 S adsorption ability, and APES-modified HZc enhanced CH 3 CHO adsorption ability in comparison to unmodified one, respectively. Sequential modification of HZc with Cu 2+ and APES also maintained H 2 S and NH 3 adsorption ability, but decreased CH 3 CHO adsorption ability. This suggests that adsorption sites for CH 3 CHO were impeded in case of formation of Cu-N coordinate bond derived from direct interaction between Cu 2+ and amino groups of APES. Therefore, use of HZc individually modified with Cu 2+ and APES is recommended to capture multiple unpleasant odors.