Comparative study of fly ash derived adsorbents, synthesis, and application

This study aimed to develop and evaluate various fly ash (FA)-derived adsorbents for TC removal, leveraging waste materials for environmental sustainability. Several adsorbents were derived from FA, including acid-modified FA (AM-FA), base-modified FA (BM-FA). and zeolite Na-P1 (ZNa-P1). Furthermore, silica nanoparticles (SiNPs) were derived from FA (FA-SiNPs) and subsequently FA-SiNPs was doped with iron to create Fe-SiNPs. Note that FA, AM-FA, BM-FA, and ZNa-P1 were tested separately to the silica nanoparticles-based adsorbents. The comparative adsorption test among FA, AM-FA, BM-FA and ZNa-P1, ZNa-P1 removed the most TC, at 90 % removal. Optimal TC removal with ZNa-P1 was achieved at 7.5 g/L dosage and pH 5. The adsorption of TC on ZNa-P1 followed pseudo-second-order kinetics and the Langmuir isotherm model, with a maximum capacity of 46.34 mg/g at 30 <b>°</b>C. The comparative adsorption tests among FA-SiNPs, SSSNPs, and Fe-SiNPs revealed that Fe-SiNPs demonstrated superior performance, removing 59 % of tetracycline. Optimal TC removal using Fe-SiNPs was achieved at a dosage of 5 g/L and within a pH range of 4-5. The adsorption of TC on Fe-SiNPs followed Elovich kinetics and the Langmuir isotherm model, with a maximum capacity of 32.31 mg/g at 30 <b>°</b>C. This study highlights the potential of FA-derived adsorbents, particularly ZNa-P1 and Fe-SiNPs, as sustainable solutions for removing TC from contaminated water. The findings contribute to advancing waste utilization strategies, particularly adsorption, for environmental remediation.