Removal of ammonium from aqueous solutions using zeolite synthesized from fly ash by a fusion method

Abstract

This article investigates the removal of ammonium from aqueous solutions using zeolite synthesized from fly ash by a fusion method, which combines alkaline fusion followed by hydrothermal treatment. The cation exchange capacity increases from 0.03 to 2.79 meq/g during the synthesis process. The effects of contact time, pH, initial ammonium concentration, adsorbent dosage, and the presence of other cations and anions are examined by batch experiments. The findings show that these parameters have significant effects on the ammonium removal using the synthesized zeolite. The effect of cations follows the order K . The Lagergren first-order, Ho' pseudo-second-order, and intraparticle diffusion kinetic models are employed to describe the kinetic data, and Ho' pseudo-second-order model provides excellent fitting. The equilibrium isotherm data are fitted to the Langmuir, Freundlich, Koble-Corrigan, Tempkin and Dubinin-Radushkevich models; the Koble-Corrigan model gives the best fit. The thermodynamic study reveals that ammonium uptake by the synthesized zeolite is an exothermic reaction. The maximum ammonium uptake capacity obtained is 24.3 mg/g. The regenerated zeolite has almost the same ammonium uptake capacity as the original zeolite. These results indicate that the synthesized zeolite is a promising material for removing ammonium from wastewater.

Ammonium removal from aqueous solution by zeolites synthesized from low-calcium and high-calcium fly ashes

“…the zeolitic materials [3,7,8]. This indicates that ammonium uptake occurs mainly by ion exchange with Na + -ions in LC-Z in this study.…”

“…The two synthesized zeolites were dried at 100°C for 12 h and then sieved through a 100 mesh (b150 μm) for further work. The XRD, SEM, SSA and CEC of the fly ashes and synthesized zeolites were analyzed using the same methods and equipments described in a previous paper [8]. The chemical compositions of the fly ashes and synthesized zeolites were measured using X-ray fluorescence spectrometer (Philips PW2404, Philips Co. Holland), and the results are listed in Table 1.…”

“…A fusion method described previously [8] was adopted for the synthesis of zeolite. The two synthesized zeolites were dried at 100°C for 12 h and then sieved through a 100 mesh (b150 μm) for further work.…”

“…As a resource utilization approach, extensive research has been carried out to synthesize zeolite using fly ash [7]. The synthesized zeolites are also used to remove the ammonium from wastewater, and the results showed that they are promising ion exchangers for ammonium removal [8,9].…”

Magnesium oxide entrapped Polypyrrole hybrid nanocomposite as an efficient selective scavenger for fluoride ion in drinking water

“…Polypyrrole (Ppy) is a well-known conducting polymer that has fascinated the researchers for various applications due to its facile synthesis, high electrical conductivity, excellent biocompatibility, redox and ion exchange properties [10,11]. Ppy chains have positively charged nitrogen atoms that may easily become major active sites for the adsorption of anions and also has a anion exchanger behavior due to the presence of exchangeable counter anions doped in its chains [12].…”