Removal of methylparaben from synthetic aqueous solutions using polyacrylonitrile beads: kinetic and equilibrium...

Area of Science:

• Environmental Chemistry
• Materials Science
• Water Treatment

Background:

• Methylparaben (MP) is a common endocrine disruptor found in aqueous environments.
• Effective removal of MP is crucial for mitigating environmental and health risks.
• Polyacrylonitrile (PAN) based materials show potential for adsorptive removal of pollutants.

Purpose of the Study:

• To investigate the efficacy of polyacrylonitrile (PAN) beads for methylparaben (MP) removal from aqueous solutions.
• To analyze the adsorption kinetics and equilibrium of MP onto PAN beads.
• To determine the rate-controlling step and evaluate the adsorption mechanism.

Main Methods:

• Batch adsorption experiments were conducted at room temperature with varying initial MP concentrations.
• Kinetic modeling was performed using pseudo-first-order, pseudo-second-order, and Elovich models.
• Equilibrium adsorption isotherms were analyzed using Langmuir, Freundlich, Dubinin-Radushkevich (D-R), and Temkin models.
• Adsorption diffusion models, including Dumwald-Wagner and intraparticle diffusion, were applied to understand the diffusion process.

Main Results:

• Adsorption kinetics followed a pseudo-second-order process.
• The Freundlich isotherm model provided the best fit for the adsorption equilibrium data.
• Diffusion analysis indicated specific rate-controlling steps, with Boyd's kinetic expression offering relevant insights.
• PAN beads demonstrated significant capacity for MP removal.

Conclusions:

• PAN beads are a promising adsorbent for the remediation of water contaminated with methylparaben.
• The adsorption process is governed by second-order kinetics and best described by the Freundlich isotherm.
• Understanding the diffusion mechanisms aids in optimizing the water treatment process using PAN beads.