Chloroquine degradation under Fenton-assisted electron beam irradiation in aqueous solution

Area of Science:

• Environmental Chemistry
• Water Treatment Technologies
• Advanced Oxidation Processes

Background:

• Pharmaceuticals in wastewater pose a significant environmental challenge.
• Chloroquine (CQ) is a persistent pharmaceutical pollutant requiring effective removal strategies.
• Conventional treatment methods struggle with complete pharmaceutical removal.

Purpose of the Study:

• To investigate the efficacy of Fenton-assisted electron beam radiation for chloroquine (CQ) removal from aqueous solutions.
• To compare the performance of this combined process with individual electron beam and Fenton processes.
• To elucidate the degradation mechanism, byproducts, and mineralization efficiency.

Main Methods:

• Electron beam irradiation was used to degrade CQ, with and without Fenton reagents.
• The Fenton process utilized hydrogen peroxide (H2O2) and ferrous iron (Fe2+).
• Degradation efficiency, mineralization (TOC/COD), dechlorination, and nitrification were assessed.

Main Results:

• Electron beam alone removed 63% of CQ at 1.5 kGy, with •OH, e_aq⁻, and H• as key radicals.
• Fenton process removed 57% CQ with 2 mM H2O2 and 0.4 mM Fe(II) in 3 hours.
• Fenton-assisted electron beam achieved 89% CQ removal, with improved mineralization, dechlorination, and nitrification, using less H2O2 and Fe2+.

Conclusions:

• Fenton-assisted electron beam radiation is a highly effective method for removing CQ from wastewater.
• The combined process offers synergistic benefits over individual treatments, leading to higher degradation and better overall water quality improvement.
• Degradation byproducts exhibit lower toxicity than the parent CQ molecule, indicating a safer end product.