Catalytic ozonation of lamotrigine with modified activated carbon: degradation, mineralization and by-products analysis

The persistence of pharmaceutical pollutants like lamotrigine (LTG) in aquatic environments poses significant risks to ecosystems and human health, requiring effective treatment strategies such as catalytic ozonation due to its potential for enhanced mineralization. In this study, the degradation and mineralization of LTG alone and mixed with other frequently detected pharmaceuticals in water, namely carbamazepine and ibuprofen, were studied. Catalytic ozonation was performed using a modified activated carbon (ACH-600) in two water matrices - ultrapure water (UW) and secondary effluent of a wastewater treatment plant (WW) containing the pharmaceuticals. Stability assays of the catalyst and phytotoxicity assessments of the treated water were also conducted. The use of the catalyst significantly impacted mineralization, improving the reduction of total organic carbon (TOC) from 26.5 % to 66.5 %. Carbamazepine and ibuprofen negatively affected LTG degradation and mineralization in mixed pollutant systems. The effect of the aqueous matrix had a more significant impact on mineralization. Phytotoxicity results showed lower toxicity in the treated water in UW compared to the contaminated water, as opposed to the samples prepared in WW. This reflects that the treatment by-products generated in the samples prepared in WW could affect plant growth, despite the treated water samples complying with Portuguese and Colombian standards for use in agricultural activities, according to the parameters measured. These results provide valuable information on the enhancement of LTG mineralization when using ACH-600 in the catalytic ozonation process, as well as the by-products generated and the phytotoxicological effects they might develop. • Pharmaceuticals can be removed via catalytic ozonation. • ACH-600 showed potential as an ozonation catalyst for LTG mineralization. • The water composition influenced LTG mineralization. • CBZ and IBF affect LTG degradation time. • Reusing the catalyst causes surface oxidation, reducing efficiency.