Functionalized Poly(arylene ether nitrile) Porous Membrane with High Pb(II) Adsorption Performance

Area of Science:

• Materials Science
• Environmental Science
• Chemical Engineering

Background:

• Porous materials with high surface area are crucial for effective wastewater treatment.
• Developing efficient adsorbents for heavy metal removal is an ongoing environmental challenge.

Purpose of the Study:

• To synthesize and characterize sulfonated poly(arylene ether nitrile) (SPEN) porous membranes for lead ion adsorption.
• To investigate the impact of synthesis parameters and solution conditions on adsorption performance.
• To evaluate the stability and reusability of the developed membranes.

Main Methods:

• Synthesis of SPEN functionalized with carboxylic acid groups.
• Fabrication of porous membranes using cetyltrimethyl ammonium bromide (CTAB) as a pore-forming agent.
• Adsorption experiments varying pH, contact time, and initial lead ion concentration.
• Kinetic modeling (pseudo-second-order, Langmuir) and thermodynamic analysis.
• Characterization using Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Thermogravimetric Analysis (TGA).

Main Results:

• Adsorption capacity decreased with increasing CTAB content, with the 0 wt% CTAB membrane showing the highest capacity (183.60 mg/g).
• Maximum adsorption capacity reached 246.96 mg/g at higher initial lead ion concentrations.
• Adsorption followed pseudo-second-order kinetics and Langmuir monolayer adsorption model.
• ATR-FTIR confirmed chelation between lead ions and carboxylic acid groups as the primary adsorption mechanism.
• Membranes demonstrated excellent thermodynamic stability and retained high adsorption efficiency after five regeneration cycles.

Conclusions:

• SPEN porous membranes are effective adsorbents for lead ions in aqueous solutions.
• The adsorption mechanism involves chelation with carboxylic acid groups, following Langmuir monolayer adsorption.
• The membranes exhibit robust performance and recyclability, indicating their potential for practical wastewater treatment applications.