Multiple heavy metal removal simultaneously by a biomass-based porous carbon

Area of Science:

• Environmental Science
• Materials Science
• Chemical Engineering

Background:

• Activated carbon is a key adsorbent for heavy metal removal.
• Sawdust, a lignocellulosic biomass, is abundant and underutilized.
• Developing sustainable and cost-effective adsorbents is crucial for environmental remediation.

Purpose of the Study:

• To produce activated carbon from sawdust using an eco-friendly, scalable method.
• To investigate the adsorption performance of sawdust-derived activated carbon for monometal and multimetal (cobalt, nickel, zinc) removal.
• To evaluate the regeneration efficiency of the produced activated carbon.

Main Methods:

• Single-stage carbonization and steam activation at 800°C to produce activated carbon from sawdust.
• Batch adsorption experiments to assess the effects of pH, initial metal concentration, adsorbent dosage, and time.
• Analysis using Freundlich and Weber & Morris models to understand adsorption mechanisms.
• Regeneration studies using dilute nitric acid, hydrochloric acid, and sulfuric acid.

Main Results:

• Sawdust-derived activated carbon demonstrated significant adsorption capacities for zinc (17.2 mg/g), nickel (6.6 mg/g), and cobalt (4.5 mg/g) in multisolute systems.
• Adsorption capacities were lower in monometal systems compared to multimetal systems.
• Experimental data best fitted the single-solute and multisolute Freundlich models.
• The activated carbon maintained its adsorption capacity over three adsorption-desorption cycles using dilute acids.

Conclusions:

• An environmentally friendly and scalable method for producing activated carbon from sawdust was successfully developed.
• Sawdust-based activated carbon is an effective adsorbent for removing cobalt, nickel, and zinc from aqueous solutions.
• The adsorbent can be regenerated using dilute acids, indicating its potential for sustainable heavy metal remediation.