Tannic acid-Fe complex derivative-modified electrode with pH regulating function for environmental remediation by...

Area of Science:

• Environmental Chemistry
• Electrochemistry
• Materials Science

Background:

• Heterogeneous electro-Fenton (hetero-EF) systems face challenges with reduced hydrogen peroxide (H2O2) electrogeneration efficiency at neutral to alkaline pH, hindering organic pollutant removal.
• Broadening the applicable pH range for hetero-EF processes is crucial for efficient wastewater treatment.

Purpose of the Study:

• To develop a novel cathode material for heterogeneous electro-Fenton (hetero-EF) treatment of organic pollutants effective over a wide pH range.
• To investigate the pH-regulating capabilities and pollutant degradation performance of the developed cathode.

Main Methods:

• Preparation of a tannic acid-Fe complex derivative-modified carbon felt (TFD@CF) cathode.
• Evaluation of the TFD@CF cathode's performance in heterogeneous electro-Fenton treatment of various organic pollutants (methyl orange, methylene blue, sulfamerazine, bisphenol A, 2,4-dichlorophenoxyacetic acid) at different pH levels.
• Treatment of actual textile dyeing secondary wastewater using the TFD@CF cathode.
• Electrochemical characterizations and reactive oxygen species (ROS) identification.

Main Results:

• The TFD@CF cathode demonstrated significant pH-regulating properties, acidifying the solution.
• Achieved >90% removal efficiency for diverse organic pollutants at neutral and alkaline pH.
• Treated textile dyeing wastewater with 83.2% COD removal at an energy consumption of 2.98 kWh kg-1 COD-1.
• Electrochemical analysis revealed enhanced electron transfer and Fe(III) electroreduction, with a 30.1% increase in acidic groups.

Conclusions:

• The TFD@CF cathode is a multifunctional material capable of efficient organic pollutant removal across a wide pH range, overcoming limitations of traditional hetero-EF systems.
• The developed cathode shows promise for treating refractory organic pollutants in industrial wastewater, particularly from textile dyeing.
• Findings offer new strategies for designing advanced hetero-EF cathodes for environmental remediation.