Microwave decomposition in the recycling of gadolinium from waste contrast agents

Abstract

Unconsumed gadolinium-based contrast agents used in magnetic resonance imaging become medical waste after application. Such a waste is a mixture of plastic, glass, and the contrast agent itself and is usually burned in a hospital incinerator. Due to this, further recyclable materials are lost, as well as gadolinium, which is a valuable industrial commodity. This work is focused on the possibilities of recycling waste containing gadolinium, when seeking optimum conditions for converting the gadolinium complex into the nitrate form applicable to further processing. The respective procedure is compared with the commonly used incineration of medical waste in terms of environmental impacts. An LCA study comparing such ecologic aspects of these two product systems was developed. The current predominance of fossil sources in the composition of the energy mix in the Czech Republic is the reason for the less favorable assessment of the newly proposed procedure.