U radu je praćena adsorpcija propan kiseline iz vodenog rastvora na visokosilikatim zeolitnim uzorcima, proizvedenim savremenim nanotehnologijama u američkoj kompaniji Zeolyst International (oznaka: CBV 28014). Kao adsorbensi korišteni su NH 4 ZSM-5 zeolit i njegova modifikovana forma-HZSM-5 (molski odnos SiO 2 /Al 2 O 3 iznosi 280). Adsorpcija je praćena u temperaturnom intervalu od 283 K do 303 K. Rezultati su pokazali da je sa porastom temperature adsorpcije količina adsorbovane propan kiseline rasla i na izvornoj i na modifikovanoj formi ZSM-5 zeolita, što ukazuje da se pored fizičke adsorpcije dešava i hemisorpcija, pri čemu su molekule kiseline vezane za aktivne centre i čvršćim hemijskim vezama. Modifikacijom osobina izvornog zeolita dobio se bolji adsorbens (HZSM-5 zeolit) za propan kiselinu, što je i očekivano obzirom na izražen hidrofobni karakter ove modifikovane forme.

Abstract:The commercial carbons have been used as adsorbents in decontamination processes due to their large specific surface, high adsorption capacity, microporous structure and specific surface reactivity. One of the most important applications of activated carbon concerns the water purification treatment. Water is often contaminated with phenol and allied polluters where zeolites, as the adsorbents, also play a significant part. In this study, the comparison of parameters obtained from the adsorption isotherms of zeolites and commercial carbons has served to clarify the zeolite surface property, as an adsorbent, on the molecular level. The phenol aqueous solution of 2.0 -4.0 mgL -1 mass concentration has been used as adsorbate. The phenol content has been determined spectrophotometrically on the basis of the color intensity of quinoid-type compound which has originated from the phenol and 4-amino antipyrin reaction with the K 3 Fe(CN) 6 as an oxidant in the alkaline medium.

This paper studies the possibility of using activated carbon as an adsorbent for diclofenac (DFC) from aqueous medium. Batch sorption experiments were performed, and the influence of different parameters was studied: adsorbent dose, contact time and temperature. The experimentally obtained results were fitted according to two linear theoretical models of isotherms: Freundlich and Langmuir and according to two different kinetic models: pseudo-first and pseudo-second order. The optimal adsorption parameters were found to be: dose of adsorbent 0,5 g; contact time 60 minutes and temperature 20ºC, and the removal efficiency of diclofenac at these parameters was 92.8%.The results showed that the adsorption process follows a pseudo-second order kinetics and better matches the Freundlich isotherm model. The values of thermodynamic parameters indicate that adsorption process is spontaneous and exothermic. Based on the obtained data, it can be concluded that commercial activated carbon is an effective adsorbent for diclofenac from aqueous solution.

This study observed adsorption of selected organic species from the aqueoussolution, EDTA and H2C2O4, at 283, 293 and 303 K. The adsorbent used was syntheticzeolite NH4BETA, product of the American company Zeolyst International, with themole ratio of SiO2/Al2O3 = 25.00, for the purpose of examining its physical-chemicalcharacteristics and obtaining more thorough information on the adsorption capacityand active centers, as well as for its potential application in purificati on of wastewatersfrom the organic pollutants. Results proved that adsorption of the adsorbates, underthe same experimental conditions, was multi-layer physical, being stronger expressedwhen the adsorbate was oxalic acid, which is logical enough since its molecule is a lotsmaller and of a simpler structure compared to the big molecule of EDTA.

U radu su prikazani rezultati adsorpcije amonijaka iz vodene sredine na dvarazličita adsorbensa: bentonitu i sintetskom zeolitu mordenitu.Dobijeni eksperimentalni rezultati su testirani primjenom Freundlich-ovog iLangmuir-ovog modela izotermi. Na osnovu vrijednosti koeficijenta korelacije (R2)utvrđeno je da se adsorpcija amonijaka iz vode na bentonitu i mordenitu pokoravaFreundlich-ovom adsorpcionom modelu. Rezultati pokazuju da bentonit ima većiadsorpcioni kapacitet nego mordenit.