Mesoporous Activated Biochar from Crab Shell with Enhanced Adsorption Performance for Tetracycline

Area of Science:

• Environmental Chemistry
• Materials Science
• Water Treatment

Background:

• Antibiotic contamination in water poses a significant environmental and health risk.
• Developing efficient and cost-effective adsorbents is crucial for removing pharmaceuticals from wastewater.

Purpose of the Study:

• To synthesize and characterize mesoporous-activated crab shell biochars.
• To evaluate the tetracycline (TC) adsorption performance of these biochars.
• To elucidate the adsorption mechanism and assess their potential for wastewater treatment.

Main Methods:

• Crab shells were converted into biochar via carbonation and activated using KOH, H3PO4, and KMnO4.
• Scanning Electron Microscopy (SEM) and porosity analysis were used for material characterization.
• Fourier Transform Infrared (FT-IR) spectroscopy identified surface functional groups.
• Adsorption experiments were conducted to determine TC adsorption capacities, isotherms, and kinetics.

Main Results:

• Three activated crab shell biochars (K-CSB, P-CSB, M-CSB) with mesoporous structures were successfully prepared.
• K-CSB exhibited the largest specific surface area (1738 m²/g) and highest TC adsorption capacity (380.92 mg/g).
• Abundant oxygen-containing functional groups (-OH, C-O, C=O) on the biochars enhanced TC adsorption.
• Adsorption followed Langmuir and pseudo-second-order models, indicating chemisorption and monolayer coverage.

Conclusions:

• Activated crab shell biochar is a highly effective and low-cost adsorbent for tetracycline removal.
• The adsorption mechanism involves multiple interactions including pore filling, hydrogen bonding, and electrostatic forces.
• These findings demonstrate the significant potential of crab shell biochar for treating antibiotic-contaminated wastewater.