20.500.12556/DKUM-70817 Formation of meso- and micro-pores in fly-ash zeolites using a three-step activation Tvorjenje mezopor in mikropor v elektrofiltrskem pepelu zeolita s tri-stopenjsko aktivacijo Researchers have comprehensively characterized alkali- activated fly-ash (the residue) and ascertained its highly zeolitic nature. In order to evaluate its potential for application as an adsorbent for the decontamination of waste water, the decisive parameters have mostly been the cation-exchange capacity, the mineralogy and the morphology of the residue. However, a study of the pore characteristics (e.g., the size and volume) of such residues is still warranted to anticipate their contaminant transport and the diffusion phenomena as a type of geotechnical engineering material. In this situation, the present study demonstrates the evolution of pores in the fly-ash after alkali activation up to three steps, and simultaneously, its effects` on other characteristics (e.g., the specific gravity, specific surface area and the cation-exchange capacity) of three types of similarly synthesized residues (the first, produced by using a NaOH aqueous solution and the other two residues, the result of alkali activation using a NaOH spent solution, the filtrates). Based on N2 gas absorption isotherms and infrared transmittance spectra, residues obtained from the second and third steps, each involving 24 hours of treatment using filtrates of 1.5-M NaOH, are established to be significantly enriched in the finer meso- and micro-pores, respectively, in comparison with a pure and macro-porous zeolite 4A. Raziskovalci so izčrpno opisali lastnosti bazno aktiviranega elektrofiltrskega pepela (ostanek) in potrdili njegove zeolitske lastnosti. Za vrednotenje njegovih uporabnih možnosti kot adsorbenta za dekontaminacijo odpadnih voda, so odločilni parametri večinoma ionska izmenjalna kapaciteta, mineralogija in morfologija. Vendar je študija lastnosti por (t.j. velikost in volumen) takšnih ostankov, še vedno osnova za predvidevanje o njihovi sposobnosti transporta onasneževalcev in pojavu difuzije. Pričujoča študija prikazuje razvoj por pri treh vrstah podobno sintetiziranih elektrofiltrskih pepelov po bazni aktivaciji in istočasno ta učinek na ostale lastnosti, t.j. specifično gravitacijo, specifično površino in ionsko izmenjalno kapaciteto. Na podlagi N2 plinske absorpcije in infrardeče spektroskopije je dokazano, da so ostanki, pridobljeni v drugi in tretji stopnji aktivacije (vsak je bil v obdelavi 24 ur z uporabo filtratov 1,5M NaOH), bistveno obogateni z mezoporami in mikroporami v primerjavi s čistim in makro poroznim zeolitom 4A. fly-ash hydrothermal treatment three-step activation pore characteristics lastnosti por onesnaževanje elektrofiltrski pepel zeoliti hidrotermalni postopek tristopenjska aktivacija true false true Angleški jezik Slovenski jezik Fakulteta za gradbeništvo, prometno inženirstvo in arhitekturo Univerze v Mariboru Znanstveno delo 2018-06-14 11:38:06 2018-06-14 11:39:10 2022-08-01 19:51:43 2019-07-11 18:20:49 2014 0 0 str. 63-69 št. 1 Letn. 11 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 1854-0171 66.046.59:549.67 215987712 281005056 1854-0171 URN:SI:UM:DK:0JZR1B18 Acta_geotechnica_Slovenica_2014_Jha,_Singh_Formation_of_meso-_and_micro-pores_in_fly-ash_zeolites_using_a_three-step_activation.pdf Acta_geotechnica_Slovenica_2014_Jha,_Singh_Formation_of_meso-_and_micro-pores_in_fly-ash_zeolites_using_a_three-step_activation.pdf 1 D5FB136E1589CB3097C3162547AAD59F 24c375b60aa4a284ecc988d19b425f935cc199982e9b63f23c22750a0d2d09e0 08925adc-7c10-11eb-bb7a-00155d0001ca 20.500.12556/dkum/3f07866e-16ef-4436-a4f1-132a58f3a50d https://dk.um.si/Dokument.php?lang=slv&id=125674 http://fgserver3.fg.um.si/journal-ags/2014-1/article-6.asp 1 https://dk.um.si/Dokument.php?lang=slv&id=125675 Fakulteta za gradbeništvo, prometno inženirstvo in arhitekturo Acta geotechnica Slovenica 0 0 0