Reductive removal of triclosan by Sn-bearing materials and cathode powder recovered from spent Liion batteries

Tin (Sn)-bearing materials, tin oxide (SnO) and elemental tin (Sn(0)), and cathode powder recovered from spent Liion batteries were examined as reductants to transform triclosan, a common antibiotic through batch experiments. The reductive removal of triclosan was rapidly observed within 1 h under the given conditions, however, the formation of a passivation layer, mainly composed of SnO2. Tin dioxide inhibited the reduction reactions on the surfaces of SnO and Sn(0). In contrast, dissolved Sn2+, formed by the addition of SnCl2, could rapidly reduce triclosan within 5 h, resulting in over 95% removal. The results supported the notion that the inhibition of Sn2+formation by SnO2 on the surface acted as a ratelimiting step in the reductive removal of triclosan by Sn(0) and SnO. Conversely, the removal of triclosan by cathode powder was due to sorption and reduction, and its efficacy was limited by increased pH. A synergistic combination of Snbearing materials and cathode powder significantly improved the reduction of triclosan. Our findings suggest that the application of cathode Sn(0)/SnO/cathode powder with SnCl2 holds promise as an effective approach for the reductive transformation of triclosan in engineered systems