RuO2-Ti Electrode-Assisted Electro-Biodegradation for Enhanced Rhodamine B Elimination
Subramani Abilaji1, Jayaraman Narenkumar2, Manickam Sivaraman Nandini3,4
1Environmental Molecular Microbiology Research Laboratory, Department of Biotechnology, Thiruvalluvar University, Vellore, Tamil Nadu, India.
Summary
Electro-oxidation (EO) combined with biodegradation effectively removes rhodamine B dye from wastewater. This dual approach significantly reduces chemical oxygen demand and total organic carbon, offering a promising solution for effluent treatment plants.
Area of Science:
- Environmental Chemistry
- Water Treatment Technologies
- Electrochemistry
Background:
- Wastewater contamination by recalcitrant organic dyes like rhodamine B (RhB) poses significant environmental challenges.
- Conventional treatment methods often struggle with complete dye removal and mineralization.
- Electro-oxidation (EO) presents a rapid and effective alternative for pollutant elimination.
Purpose of the Study:
- To evaluate the efficacy of electro-oxidation (EO) and combined EO-biodegradation (EO and BD) for rhodamine B (RhB) dye removal.
- To assess the mineralization efficiency and identify intermediate products during the treatment process.
- To determine the toxicity of RhB and its degradation intermediates.
Main Methods:
- Utilized titanium-based mesh electrodes (Ti/TiO2-RuO2) for electro-oxidation.
- Applied a direct current of 20 mA/cm² for the EO system.
- Measured color removal using UV-spectrophotometry and assessed chemical oxygen demand (COD) and total organic carbon (TOC).
- Employed Fourier transform infrared spectroscopy (FTIR) and High-Resolution Mass Spectrometry (HRMS) for chemical analysis.
- Conducted toxicity studies using LC50 and EC50 values for aquatic organisms.
Main Results:
- Achieved significant decolorization of 10 ppm RhB within 30 minutes.
- Reduced COD by 78% with EO alone and 93% with EO and BD.
- Reduced TOC by 57.2% with EO and 86.7% with EO and BD, indicating effective mineralization.
- FTIR and HRMS identified key functional groups and intermediate products (NH, C-N, C=O) during degradation.
- Toxicity studies showed that EO and BD intermediates were largely non-harmful.
Conclusions:
- Combined electro-oxidation and biodegradation is highly effective for removing and mineralizing rhodamine B dye.
- This integrated treatment approach offers a sustainable and efficient solution for wastewater effluent treatment.
- The process leads to the generation of less harmful intermediates, reducing overall environmental toxicity.
