Electro-reductive deiodination of iohexol catalyzed by vitamin B12 and biodegradability investigation

Owing to their high consumption for X-ray diagnose and rapid excretion from organism, iodinated contrast media (ICM) are often found in source waters. It is a serious public health concern due potential generate highly toxic disinfection by-products. Reductive deiodination of ICM considered as promising approach degrade them allows the possible recovery iodide ions. Electrocatalytic reduction iohexol, an ionic ICM, was performed presence vitamin B12 catalyst. Vitamin chosen owing its catalytic activity toward dehalogenation processes positive effect on biodegradation pollutants. The conditions electrocatalysis were optimized favor electrocatalytic process over direct reduction, leading enhancement reaction kinetic current efficiency. A total iohexol achieved after 1 h electrolysis. biological treatment with activated sludge underlined low decrease dissolved organic carbon even electroreduction. However, concentration decreased significant biotransformation occurred, slightly improved by B12. identification main by-products highlighted oxidation primary secondary alcohols alkyl chains.