Automated H₂O₂ monitoring during photo-Fenton processes using an Arduino self-assembled automatic system.

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Green Chemistry

Background:

• Photo-Fenton degradation is an effective method for removing organic pollutants like caffeine.
• Continuous monitoring of hydrogen peroxide (H₂O₂) is crucial for optimizing photo-Fenton processes.
• Manual H₂O₂ monitoring can be labor-intensive and expose operators to hazards.

Purpose of the Study:

• To develop and evaluate a low-cost, Arduino-based automated system for monitoring H₂O₂ consumption.
• To compare the analytical performance of the automated system with traditional UV-Vis spectrophotometry.
• To optimize the photo-Fenton degradation of caffeine using the automated monitoring system.

Main Methods:

• An Arduino self-assembled automatic system was utilized for continuous H₂O₂ monitoring via colorimetric reaction.
• High-performance liquid chromatography (HPLC) was used for sample analysis.
• Design of Experiments (DoE) was employed to optimize photo-Fenton parameters (H₂O₂ concentration, iron concentration, caffeine concentration).

Main Results:

• The automated system demonstrated superior analytical performance with lower limits of detection (LOD) and quantification (LOQ) compared to manual UV-Vis spectrophotometry.
• LOD: 0.032 mM, LOQ: 0.106 mM for the automatic system vs. LOD: 0.064 mM, LOQ: 0.213 mM for UV-Vis.
• Optimization of photo-Fenton treatment was achieved by investigating key operational parameters.

Conclusions:

• The Arduino-based automated system offers a cost-effective, precise, and efficient solution for monitoring H₂O₂ in photo-Fenton degradation.
• The system aligns with Green Analytical Chemistry principles by reducing workload, reagent consumption, and waste.
• Automation enhances safety by minimizing operator intervention and exposure to UV radiation.