Iron bioremediation by utilizing biochar-bacterial composites.

Area of Science:

• Environmental Science
• Biotechnology
• Materials Science

Background:

• Groundwater iron contamination from industrial, urban, and agricultural activities poses a significant challenge.
• Surface immobilization of bacteria on biochar is a promising strategy for adsorption-based remediation.

Purpose of the Study:

• To investigate the adsorption behavior of Fe(II) ions using a bacterial-biochar adsorbent.
• To evaluate the impact of Bacillus subtilis immobilized on rice husk biochar on Fe(II) adsorption capacity.
• To analyze adsorption using sorption and kinetic models and material properties.

Main Methods:

• Rice husk biochar immobilized with Bacillus subtilis.
• Characterization using SEM, BET surface area analysis, and FTIR spectroscopy.
• Batch adsorption experiments with Fe(II) concentrations (10-40 mg/L), kinetic, and isotherm modeling.

Main Results:

• The bacterial-biochar adsorbent achieved 79.3% Fe(II) removal, surpassing pristine biochar.
• Enhanced BET surface areas (67.76-91.84 m²/g) correlated with improved adsorption.
• FTIR analysis identified functional groups and metal carbonate structures indicating active biosorption sites.
• Optimal performance observed at 10-15 mg/L Fe(II) concentration.
• Kinetic and isotherm models confirmed heterogeneous adsorption sites.

Conclusions:

• Surface immobilization of Bacillus subtilis on rice husk biochar significantly enhances Fe(II) adsorption.
• This bacterial-biochar immobilized adsorbent shows potential for green biotechnology applications in groundwater remediation.