Elimination of the iodinated contrast agent iohexol in water, wastewater and urine matrices by application of photo-Fenton and ultrasound advanced oxidation processes

The use of ultrasound and photo-Fenton advanced oxidation processes has been investigated for the treatment of aquatic media contaminated with the iodinated contrast agent Iohexol. Iohexol is primarily introduced in the water network from hospitals discharging the urine of patients submitted to medical imaging. Treatment options have been considered for eliminating either highly concentrated solutions (up to 6 g L−1) at the hospital source (in urine) or highly diluted (in the mg L−1 range) within municipal wastewater. Although the efficiency of ultrasound was shown to be low, complete Iohexol removal was achieved by application of photo-Fenton in diluted urine, Advantages and disadvantages of each option are discussed and the biodegradability of solutions subjected to the treatment has been evaluated.