Occurrence and Removal of Pharmaceutical Contaminants in Urine: A Review

With the development of world economies and the continuous improvement of living standards, pharmaceutical and personal care products (PPCPs) have attracted significant attention because of their widespread detection in wastewater and the natural environment. Their biological toxicity, environmental persistence, and other hazardous characteristics might pose a threat to the ecological environment and human health. How to treat source-separated urine as a valuable recyclable resource has become a novel challenge. In this review, we briefly described the sources of pharmaceuticals, explored the various metabolic pathways of pharmaceuticals, and concluded that urinary excretion is the primary metabolic pathway of pharmaceuticals. Next, the current status of pharmaceutical contamination in human urine, sewage plants, and surface water was summarized. It is shown that the concentration of pharmaceuticals in human urine is usually 2-3 orders of magnitude higher than that in sewage plants and surface water. Then, the research progress of various technologies to treat pharmaceutical contaminants in urine was analyzed and compared, indicating the promise of advanced oxidation technologies to treat such wastewater, among which electrochemical oxidation has received widespread attention due to its advantages of cleanness, flexibility, and controllability. Therefore, the research progress of electrode materials and electrochemical technology to treat urine was reviewed, and finally, the future development direction was proposed, namely, coupling membrane treatment technology with intellectual development, which will help realize the scale and industrialization of source-separated urine treatment.