Manganese on P, N self-doped biochar toward promoting periodate activation for highly efficient tetracycline degradation: Performance and mechanisms

In this study, a manganese co-doped with phosphorus and nitrogen pigeon guano-derived biochar catalyst (Mn/PN-PGC) was constructed for the rapid removal of tetracycline hydrochloride (TC) by activated periodate (PI). The results show that the Mn/PN-PGC materials obtained after Mn doping have increased defects and a higher specific surface area, resulting in more PI catalytic active sites. At room temperature, 0.1 g·L −1 of Mn/PN-PGC and 0.1 g·L −1 of PI could achieve 92.2 % TC removal efficiency with a rate constant of 0.257 min −1 . The removal of TC remained above 84.32 % over a wide pH range. EPR tests, quenching experiments, probe experiments and electrochemical tests demonstrated the mechanism of the synergistic degradation of TC by radical (IO 3 •/•O 2 − /•OH) and non-radical of electron transfer. Additionally, the ecotoxicity was reduced after treatment with the Mn/PN-PGC/PI system, with no toxic reactive iodine production detected. The resourceful utilization of agricultural wastes in this study can alleviate the problem of agricultural waste management, promote sustainable practices, and ultimately facilitate the evolution of advanced and sustainable methods for the remediation of antibiotics in wastewater.