Zeolite Composite Materials from Fly Ash: An Assessment of Physicochemical and Adsorption Properties

Abstract

Waste fly ash, with both low (with the addition of vermiculite) and high contents of unburned coal, were subjected to hydrothermal syntheses aiming to obtain zeolite composite materials—zeolite + vermiculite (NaX–Ver) and zeolite + unburned carbon (NaX–C). The composites were compared with parent zeolite obtained from waste fly ash with a low content of unburned carbon (NaX–FA). In this study, the physicochemical characteristics of the obtained materials were evaluated. The potential application of the investigated zeolites for the adsorption of ammonium ions from aqueous solutions was determined. Composite NaX–Ver and parent zeolite NaX–FA were characterized by comparable adsorption capacities toward ammonium ions of 38.46 and 40.00 mg (NH4+) g−1, respectively. The nearly 2-fold lower adsorption capacity of composite NaX–C (21.05 mg (NH4+) g−1) was probably a result of the lower availability of ion exchange sites within the material. Adsorbents were also regenerated using 1 M NaCl solution at a pH of 10 and subjected to 3 cycles of adsorption–desorption experiments, which proved only a small reduction in adsorption properties. This study follows the current trend of waste utilization (fly ash) and the removal of pollutants from aqueous solutions with respect to their reuse, which remains in line with the goals of the circular economy.

Efficiency of Modified Natural Clinoptilolite Tuff for As(III) and As(V) Uptake from Model Polluted Water

“…The calculated value for 𝑲 𝑳 = 0.0858 L/μg for Fe-Cpt is in good agreement with the literature data [25,[32][33][34][35] for similar adsorbents (Fe-OH-coated various zeolites and other natural materials). The calculated maximum adsorption capacity (32.9mg/g) was less than the capacity (79mg/g) of Fe-treated activated carbon [25] but greater than that for the goethite (25mg/g) and is comparable with data published by other authors [30,35,36]. The results for adsorption of arsenate are like the data obtained for Fe-coated sorbents.…”

Decarbonatization of Energy Sector by CO2 Sequestration in Waste Incineration Fly Ash and Its Utilization as Raw Material for Alkali Activation

“…Great attention is being paid nowadays to so-called class C fly ashes or class F fly ashes containing extra calcium, as a high calcium content was reported to lower the mechanical properties of FAs’ alkali-activated derivatives [ 7 ]. Some recent findings underline the utilization of fly ashes as additives to cement [ 8 ] and raw materials for porous materials syntheses such as zeolites [ 9 , 10 , 11 ], mesoporous silica [ 12 ], metal-organic frameworks (MOFs) [ 13 ], and alkali-activated materials [ 14 , 15 ].…”

Petroleum sludge ash-derived MCM-41-silver nanocomposites for enhanced photocatalysis and antimicrobial effect in water treatment

“…Several studies have demonstrated the successful production of various mesoporous materials, including zeolites, [15][16][17] SBA15, 18 SBA16, 19 and others, using fly ash as a precursor. Among these mesoporous materials, MCM-41, which can be synthesized from different sources of silica, 20 has emerged as a versatile material with numerous applications in various scientific and engineering fields.…”