Adsorption Performance of Cu-Fe Bimetallic-Modified Coconut Shell Activated Carbon for Ultra-Low-Concentration SO₂

Area of Science:

• Environmental Science
• Materials Science
• Chemical Engineering

Background:

• Industrial emissions pose significant air quality challenges.
• Effective removal of extremely low concentrations of sulfur dioxide (SO2) is crucial for environmental protection.

Purpose of the Study:

• To develop and optimize a Cu-Fe bimetallic-supported adsorbent for highly efficient SO2 capture.
• To investigate the influence of various parameters on SO2 adsorption performance.
• To analyze the adsorbent's regeneration stability and deactivation mechanisms.

Main Methods:

• Preparation of Cu-Fe bimetallic adsorbents using alkali-activated coconut shell activated carbon (AC-OH) via impregnation.
• Systematic investigation of parameters including metal loading, Cu/Fe ratio, and operating conditions.
• Characterization using techniques such as XRD, FT-IR, XPS, and SEM.

Main Results:

• Optimal performance achieved with 5% Cu and 3% Fe loading, yielding a breakthrough time of 36.5 h and a capacity of 14.424 mg/g.
• Coexistence of O2 and H2O significantly enhances SO2 adsorption.
• Reduced space velocity prolongs breakthrough time.
• Adsorbent activity decreased to 72.7% after two cycles due to sulfate accumulation and active component loss.

Conclusions:

• The developed Cu-Fe bimetallic adsorbent demonstrates high potential for deep purification of extremely low concentrations of SO2.
• Understanding the structure-activity relationship and deactivation mechanisms is key for further adsorbent development.
• The adsorbent shows promise for industrial applications in air quality control.