Bismuth impregnated biochar for efficient uranium removal from solution: Adsorption behavior and interfacial
Jun Liao1, Xiaoshan He2, Yong Zhang3
1Division of Target Science and Fabrication, Research Center of Laser Fusion, China Academy of Engineering Physics, P. O. Box 919-987, Mianyang 621900, China; School of National Defence Science & Technology, Southwest University of Science and Technology, Mianyang 621010, China.
The Science of the Total Environment
|January 17, 2022
Summary
This study developed bismuth oxide-doped biochar from horse manure for efficient uranium(VI) removal from wastewater. The material demonstrated a high adsorption capacity and fast kinetics, indicating its potential for environmental remediation.
Area of Science:
- Environmental Science
- Materials Science
- Chemistry
Background:
- Uranium(VI) contamination poses significant environmental and health risks.
- Effective remediation strategies for uranium-contaminated water are crucial.
- Biochar, a sustainable material, shows promise for adsorbing heavy metals.
Purpose of the Study:
- To synthesize and characterize bismuth oxide (Bi2O3) doped biochar from horse manure.
- To evaluate the adsorption performance of the developed biochar for uranium(VI) removal.
- To investigate the adsorption mechanism of uranium(VI) onto the modified biochar.
Main Methods:
- Horse manure was modified with H2O2 and bismuth nitrate, then pyrolyzed at 500°C under nitrogen to produce Bi2O3-doped biochar.
- Batch adsorption experiments were conducted to assess uranium(VI) removal efficiency, adsorption capacity, and kinetics.
- Interfering ions and solution parameters were varied to understand adsorption behavior.
- Adsorption mechanisms were explored through analysis of interaction factors.
Main Results:
- The synthesized biochar exhibited a rapid adsorption equilibrium time (<80 min) and a high adsorption rate (5.0 mg/(g·min)).
- The material achieved a high removal efficiency (93.9%) and a large adsorption capacity (516.5 mg/g) for uranium(VI) under optimal conditions (298 K, pH 4).
- Adsorption was largely unaffected by interfering ions and ionic strength, except for Al3+, Ca2+, CO32-, and PO43-.
Conclusions:
- Bi2O3-doped horse manure biochar is a highly effective adsorbent for uranium(VI) removal.
- The adsorption process involves multiple mechanisms including surface complexation, ion exchange, electrostatic attraction, precipitation, and reduction.
- This modified biochar shows significant potential for remediating uranium(VI)-contaminated wastewater.
