Enhanced Fe(ii)/Fe(iii) cycle by boron enabled efficient Cr(vi) removal with microscale zero-valent iron

Area of Science:

• Environmental Science
• Materials Science
• Chemistry

Background:

• Microscale zero-valent iron (mZVI) is crucial for pollution remediation.
• Limited electron transport in mZVI hinders its application.
• Hexavalent chromium (Cr(VI)) poses significant environmental and health risks.

Purpose of the Study:

• To enhance the performance of mZVI for Cr(VI) removal.
• To investigate the mechanism of boron powder in accelerating the iron cycle.
• To provide an efficient and eco-friendly mZVI remediation approach.

Main Methods:

• Addition of boron powder to mZVI for Cr(VI) remediation.
• Quantification of Cr(VI) removal rates and Cr(III) generation.
• Electrochemical analysis to determine potential gap values (ΔEp).

Main Results:

• Boron powder addition increased the Cr(VI) removal rate by 2.1 times.
• Boron promoted the reduction of Cr(VI) to Cr(III) and Fe(III) to Fe(II).
• Boron decreased the potential gap (ΔEp) from 0.668 V to 0.556 V, indicating enhanced electron transfer.

Conclusions:

• Boron powder acts as an electron sacrificial agent, promoting the iron cycle.
• This enhances the reactivity of mZVI for efficient Cr(VI) remediation.
• The findings support the broader application of mZVI technology in environmental cleanup.