Lignin-based adsorbent-catalyst with high capacity and stability for polychlorinated aromatics removal

Area of Science:

• Materials Science
• Environmental Chemistry
• Chemical Engineering

Background:

• Lignocellulose valorization offers sustainable alternatives for waste utilization.
• Developing efficient adsorbents for toxic gaseous pollutants is crucial for environmental protection.
• Lignin, a byproduct of lignocellulose processing, presents potential as a precursor for advanced materials.

Purpose of the Study:

• To prepare and evaluate lignin-based adsorbents for the removal of ortho-dichlorobenzene (o-DCB).
• To investigate the adsorption capacity, stability, and catalytic activity of these novel materials.
• To explore the underlying properties contributing to the adsorbents' performance.

Main Methods:

• Synthesis of three lignin-based adsorbents (LC-A, LC-B, LC-C).
• Testing adsorption capacities for o-DCB removal and comparing with activated carbon.
• Evaluating adsorbent stability through multiple recycling runs.
• Assessing the performance of a ruthenium-supported lignin-based catalyst (LC-B) for o-DCB removal across a temperature range.

Main Results:

• LC-B demonstrated superior adsorption capacity (718.2 mg/g) compared to LC-A, LC-C, and activated carbon.
• LC-B exhibited excellent recyclability, maintaining high adsorption capacity after five cycles.
• LC-B supported Ru catalyst achieved >80% o-DCB removal over a wide temperature range (50-300°C).
• High surface area (1618.55 m²/g), pore structure, graphitization, and hydroxyl groups contributed to LC-B's performance.

Conclusions:

• Lignin-based adsorbents, particularly LC-B, are highly effective for removing toxic gaseous pollutants like o-DCB.
• These materials offer a cost-effective and sustainable approach to pollution control.
• The study highlights the potential of lignin valorization for environmental applications.