To minimize environmental pharmaceutical micropollutants, treatment of human urine can be an efficient approach because of the high pharmaceutical concentration and toxic potential excreted in urine. This study investigates the application of ferrate (Fe(VI)) oxidation to degrade pharmaceuticals (carbamazepine (CBZ), naproxen (NAP), sulfamethoxazole (SMX) and trimethoprim (TMP)) in synthetic hydrolyzed human urine. Interesting new matrix effects from common organic components in urine were discovered. Creatine and hippuric acid showed limited scavenging effects on the oxidation of these four pharmaceuticals by Fe(VI). However, creatinine significantly enhanced the oxidation rates of CBZ, TMP, and SMX by Fe(VI), while only limitedly impacted NAP removal. Amine-specific structures were found to be responsible for creatinine enhancement according to the investigation of subunits of TMP and SMX (e.g., 2,4-damino-5-methylpyrimidine 3,4,5-Trimethoxytoluene, 3-amino-5-methylisoxazole (AMI), 3,5-dimethylisoxazole (DMI), and aniline). Intermediate iron species Fe(V) was proposed as the major reactive species in the Fe(VI)-creatinine system. For the first time, a kinetic model involving Fe(V) contribution to the substrate removal was proposed and successfully captured the pharmaceutical removal in the Fe(VI)-creatinine system. Moreover, it also predicted the rate constants between Fe(V) and the substrates (50 – 850 M<sup>-1</sup>s<sup>-1</sup> ), which agreed well with previous literature for similar structures. Overall, the enhancement effect of creatinine could render Fe(VI) a promising advanced oxidation technology for removal of pharmaceuticals in hydrolyzed urine.

Ferrate oxidation of pharmaceuticals in hydrolyzed urine: Impacts of organic constituents

2019 Fall National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.