Electrochemical Processes Coupled to a Biological Treatment for the Removal of Iodinated X-ray Contrast Media Compounds

Abstract

Electrochemical reduction and then oxidation of diatrizoate allow total deiodination and improvement of the biodegradability of the solution leading to a mineralization yield of 60%.

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

“…were consistent with the biodegradability estimated by the BOD5/COD ratio since the mineralization yield was still very low (around 10-20%) after 21 days. In opposite with previous results obtained with diatrizoate [18], the dehalogenation of iohexol did not improve its biodegradability. For a better understanding of the biodegradation mechanism, the concentrations of iohexol and of released iodide ions were monitored during its biological treatment with and without vitamin B12 (Fig.…”

“…Among physicochemical processes, advanced oxidation processes showed their efficiency but the formation of toxic intermediates has been reported for incomplete mineralizations [9][10][11][12][13]. Reductive deiodination processes, especially electroreduction, are very promising because ICM are easy to reduce and hard to oxidize [14][15][16][17][18]. In addition, electroreduction can be considered as a green technique to remove halogenated pollutants since extra reducing agents are not needed.…”

“…We have previously shown that the removal of carbon-iodide bond improved the biodegradability of diatrizoate, a highly biorecalcitrant ICM [18]. The coupling of an electrocatalytic reduction process with a cost-effective biological treatment for the total mineralization of ICM is particularly interesting since it would also allow the recovery of iodide ions in the industrial process.…”

Improvement of the biodegradability of diatrizoate by electroreduction of its amido groups

“…Reductive deiodination of diatrizoate has been also investigated since it allows an improvement of its biodegradability and the possible recovery of iodide ions, which is particularly interesting to reduce its production cost [14,15]. Furthermore, electrochemical reduction processes are particularly promising due to the decreasing cost of renewable electricity, while no extra chemicals is needed [16][17][18].…”

Study on the Preparation and System of Desulfonated Anti-High Temperature Fluid Loss Agent

“…The focus of the biodegradability test of the drilling fluid is mainly to assess the biodegradability of the treatment agents added to the drilling fluid system. State-of-the-art evaluation methods include BOD5/CODCr (BOD refers to the biochemical oxygen consumption, while COD refers to the chemical oxygen consumption) [ 21 , 22 ]. The ratio BOD5/CODCr defines the biodegradability of organic matter.…”