Adsorptive removal of phosphorus from aqueous solutions using natural and modified coal solid wastes

Abstract

An invaluable utilization approach for industrial wastes is to employ them as effective adsorbents for environmental pollutants. This study aimed to investigate the phosphorus (P) adsorption behavior of coal wastes and zeolite in three forms of pristine powder (CP and ZP), nanoparticles (CNP and ZNP), and Fe (III)-modified nanoparticles (MCNP and MZNP). The adsorbents were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS) analyses. The effects of pH, initial P concentration, and contact time were studied under batch mode. Results showed an optimum pH range of 2–6 for the P adsorption process. The pseudo-second-order kinetic model and the Langmuir isotherm described the P adsorption data well. The P adsorption capacity of the studied adsorbents was enhanced after modifications. However, the coal-based modified adsorbents represented higher P adsorption performances rather than the zeolite ones. The maximum P adsorption capacity (Qmax) values were obtained as 0.36, 3.23, and 30.48 mg g−1 for CP, CNP, and MCNP, and 0.80, 2.84, and 6.99 mg g−1 for ZP, ZNP, and MZNP, respectively. The surface complexation, ligand exchange, and electrostatic attraction processes were identified as the main P adsorption mechanisms by the studied adsorbents.

Semi-quantitative analysis study of the impact of microwave treatment on fly ash

“…of particles quickly, thus forming more, larger and more uniform pore structures. These pores could have increased fly ash particles' specific surface area and pore volume, enhancing their adsorption performance (Hosseinpour et al, 2023). It could have also increased the broken surface of the particle surface, i.e., the reaction contact area, to enhance the activation effect and thus enhance the adsorption performance.…”