Degradation of Triclosan by Recyclable MnFe₂O₄‑Activated PMS: Process Modification for Reduced Toxicity and Enhanced Performance

The degradation of triclosan (TCS) by MnFe₂O₄/PMS was investigated. The system was able to remove TCS in less than 20 min. Recycled MnFe₂O₄ was found to be more efficient than fresh MnFe₂O₄ for TCS degradation as a result of the alteration of Mn sites by peroxymonosulfate (PMS), leading to an extra degradation pathway where no oxidants are required. A modified treatment process is originally proposed in this study by preactivating the catalyst with PMS prior to the succeeding reactions, as the toxicity test showed that PMS may have a lethal effect on aquatic animals. The results showed that the preactivated catalyst provides satisfactory results with the total removal of TCS in 20 min at neutral pH, whereas the modified process minimizes the direct addition of PMS to the bulk solution and therefore the potential toxicity to the aquatic life forms.