Iodinated Contrast Media-From Clinical Use to Environmental Concern and Treatment Possibilities

Area of Science:

• Environmental Chemistry
• Water Treatment Technologies
• Toxicology

Background:

• Iodine-based contrast agents (ICMs) are essential for medical imaging but pose environmental challenges due to their persistence in wastewater.
• Conventional water treatment methods are ineffective at removing ICMs, leading to their accumulation in aquatic environments.
• ICM transformation during water disinfection generates iodine-based disinfection by-products (I-DBPs) with significant cytotoxic, genotoxic, and ecotoxic effects.

Purpose of the Study:

• To review the effectiveness of Advanced Oxidation Processes (AOPs) in degrading ICMs and mitigating I-DBP formation.
• To identify limitations of current AOPs for large-scale ICM remediation.
• To highlight future research directions for sustainable ICM management in water treatment.

Main Methods:

• Literature review of various AOPs, including ozonation, UV/H2O2, UV/chlorine, photocatalysis, Fenton reactions, and electrochemical oxidation.
• Analysis of AOP efficiency in decomposing specific ICMs like iopamidol, iohexol, iopromide, and diatrizoate.
• Evaluation of AOPs' capacity to limit the formation of harmful I-DBPs.

Main Results:

• AOPs demonstrate high degradation efficiencies for ICMs under laboratory conditions.
• Common AOPs effectively decompose various ICMs using reactive radicals.
• Challenges remain, including incomplete mineralization, formation of secondary pollutants, and high operational costs.

Conclusions:

• AOPs are promising for removing ICMs and reducing I-DBP formation, but face implementation hurdles.
• Further research is needed to optimize AOPs for real-world water matrices and assess by-product toxicity.
• Developing cost-effective hybrid AOP systems is crucial for safeguarding water quality and public health.