Sorption kinetics of polycyclic aromatic hydrocarbons removal using granular activated carbon: intraparticle...

Area of Science:

• Environmental Chemistry
• Water Treatment Technologies
• Adsorption Science

Background:

• Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants in aqueous environments.
• Effective removal of PAHs is crucial for water quality and environmental protection.
• Granular activated carbon (GAC) is a widely used adsorbent for water purification.

Purpose of the Study:

• To evaluate granular activated carbon (GAC) as a sorbent for removing polycyclic aromatic hydrocarbons (PAHs) from aqueous solutions.
• To investigate the kinetics of PAH sorption onto GAC.
• To elucidate the diffusion mechanisms governing the PAH sorption process.

Main Methods:

• Kinetic measurements for six PAHs using GAC.
• Scanning Electron Microscopy (SEM) for GAC morphology analysis.
• Analysis using homogenous particle diffusion model (HPDM) and shell progressive model (SPM).

Main Results:

• Sorption process controlled by diffusion of PAHs into the reacted layer.
• Effective particle diffusion coefficients (D(eff)) ranged from 1.1 x 10(-13) to 6.0 x 10(-14) m(2) s(-1).
• Surface diffusion model provided a deeper understanding, with apparent surface diffusivities comparable to literature values for similar compounds.

Conclusions:

• GAC is a suitable sorbent for PAH removal from water.
• Diffusion kinetics, encompassing both pore and surface diffusion, govern the sorption process.
• The study provides valuable insights into the mechanisms of GAC-based PAH remediation.