Decentralized treatment of urine with zerovalent iron – A feasible way to prevent the emissions of iodinated contrast media into the aquatic environment?

Abstract

The use of iodinated contrast media (ICM) is restricted to ambulatory and stationary computed tomographic examinations. Due to their limited transformation in the human body and wastewater treatment plants, ICM are frequently detected in the aquatic environment. The elimination of these compounds from the human body is typically very fast (T1/2 ~2 h). Consequently, temporary separation of the patients’ urine from sewage is an effective measure to decrease emissions of ICM into the water cycle. An interesting option to collect the first urine fractions (8–10 h after the examination) is the usage of collecting-bags filled with absorber material. The resulting solidified urine is discarded as household waste and burned accordingly. In the here presented study an alternative decentralized approach using zerovalent iron (ZVI) for the dehalogenation of ICM is presented. Effective treatment can be realized by using nanoscale ZVI. However, limited patient compliance must be expected due to the comparably high level of complexity of the derived procedure.