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Optimization of chromium (VI) reduction in aqueous solution using magnetic Fe3O4 sludge resulting from
Pınar Belibagli1, Zelal Isik2, Nadir Dizge2
1Department of Energy Systems Engineering, Tarsus University, Tarsus, Turkey.
Plos One
|December 31, 2024
Summary
Electro-coagulated Fe3O4 sludge effectively removes Cr(VI) ions from wastewater. This inexpensive adsorbent achieved 97.0% removal efficiency and can be reused multiple times, offering a sustainable solution.
Area of Science:
- Environmental Chemistry
- Materials Science
- Wastewater Treatment
Background:
- Hexavalent chromium (Cr(VI)) poses significant environmental and health risks.
- Wastewater treatment often generates sludge that requires disposal.
- Reusing electro-coagulated sludge presents an opportunity for sustainable waste management.
Purpose of the Study:
- To investigate the efficacy of electro-coagulated sludge as an adsorbent for Cr(VI) ion reduction.
- To optimize the parameters for Cr(VI) removal using this sludge.
- To evaluate the reusability and adsorption mechanism of the sludge.
Main Methods:
- Electro-coagulated sludge from citric acid wastewater treatment was used.
- Response surface methodology was employed for parameter optimization (pH, initial Cr(VI) concentration, contact time, adsorbent dosage).
- Adsorption isotherms (Freundlich) and kinetics (pseudo-second order) were analyzed.
Main Results:
- Optimal Cr(VI) reduction achieved 97.0% removal efficiency and 15.1 mg/g adsorption capacity.
- Optimum conditions: pH 5.0, 1.5 g/L sludge dosage, 10 mg/L initial Cr(VI) concentration, 45 min contact time.
- The adsorbent demonstrated high reusability, maintaining efficiency through the 5th cycle.
Conclusions:
- Electro-coagulated Fe3O4 sludge is a highly effective and economical adsorbent for Cr(VI) removal.
- The adsorption process follows Freundlich isotherm and pseudo-second order kinetics, indicating efficient surface adsorption.
- This study highlights a sustainable approach to wastewater treatment by reusing industrial sludge.
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