Coupling anodic oxidation, biosorption and alternating current as alternative for wastewater purification

Area of Science:

• Environmental Chemistry
• Electrochemistry
• Materials Science

Background:

• Anodic oxidation is effective for refractory effluent treatment, but anode stability is crucial.
• Expensive alternatives exist for enhancing anode stability.
• A simple, cost-effective method is needed to improve anode performance.

Purpose of the Study:

• To enhance the stability of stainless steel/lead dioxide (SS/PbO2) anodes.
• To evaluate the performance of these anodes in treating methylene blue and industrial textile wastewater.
• To investigate a novel coupling process combining electrochemical oxidation with biosorption.

Main Methods:

• Electrodeposition of SS/PbO2 anodes using pulsed current.
• Coupling electrochemical oxidation with biosorption using Luffa cylindrica.
• Optimization of the coupling process for colored and industrial wastewater treatment.
• Analysis using Atomic Absorption Spectroscopy (AAS) and Liquid Chromatography-Mass Spectrometry (LC/MS).

Main Results:

• The coupling process achieved 98.7% methylene blue removal (60 min, AC) and 80.02% (120 min, DC).
• Anodic oxidation alone removed 62.84% methylene blue (120 min, AC) and 46.87% (180 min, DC).
• Chemical Oxygen Demand (COD) removal reached 91.32% (AC) and 75.48% (DC) with the coupling process.
• Lead ion (Pb2+) levels were within permissible standards.
• Generated by-products were identified, and treated water proved suitable for reuse via germination tests.

Conclusions:

• The coupling process significantly enhances wastewater treatment efficiency and speed compared to anodic oxidation alone.
• Alternating current (AC) improves both speed and efficiency in both processes.
• The developed method offers a stable and effective solution for refractory effluent treatment, enabling water reuse.