Enhanced Adsorption Performance of Zn/Co-Modified Biochar for Cu(II) and Cd(II)

Area of Science:

• Environmental Chemistry
• Materials Science
• Green Chemistry

Background:

• Heavy metal contamination in wastewater poses significant environmental and health risks.
• Agricultural residues often present disposal challenges and can be repurposed for environmental remediation.
• Zeolitic imidazolate frameworks (ZIFs) offer tunable properties for adsorption applications.

Purpose of the Study:

• To develop functionalized biochar from Camellia oleifera shell for enhanced heavy metal ion removal.
• To investigate the synergistic modification of biochar with ZIFs precursors.
• To evaluate the adsorption performance for copper (Cu-II) and cadmium (Cd-II) ions.

Main Methods:

• Agricultural residues (Camellia oleifera shell) were modified with ZIFs precursors.
• In situ introduction of Zn and Co, followed by pyrolysis, co-carbonization, and KOH activation.
• Preparation of nine types of functionalized biochar (BCX-T).
• Systematic characterization of structural properties and adsorption performance.

Main Results:

• BC8-500 showed a 2.1-fold increase in Cu-(II) adsorption capacity (31.61 mg/g) compared to unmodified biochar.
• BC9-500 demonstrated a 6.4-fold increase in Cd-(II) adsorption capacity (111.43 mg/g).
• Adsorption mechanisms involved chemical adsorption, multilayer adsorption, complexation (Cu-II), and precipitation (Cd-II).

Conclusions:

• Functionalized biochar derived from Camellia oleifera shell shows high efficiency for Cu-(II) and Cd-(II) removal.
• The synergistic modification approach effectively enhances biochar adsorption capabilities.
• This method provides a sustainable pathway for agricultural waste valorization and wastewater treatment.