Abstract
In this work, NiCo(2)O(4) was synthesized from bimetallic oxalate and utilized as a heterogeneous catalyst to active peroxymonosulfate (PMS) for the degradation of tetracycline (TC). The degradation efficiency of TC (30 mg/L) in the NiCo(2)O(4) + PMS system reached 92.4%, with NiCo(2)O(4) exhibiting satisfactory reusability, stability, and applicability. Radical trapping test and electron paramagnetic resonance (EPR) results indicated that SO(4)(•-), •OH, O(2)(•-), and (1)O(2) were the dominating reactive oxygen species (ROS) for TC degradation in the NiCo(2)O(4) + PMS system. Seven intermediates were identified, and their degradation pathways were proposed. Toxicity assessment using T.E.S.T software (its version is 5.1.1.0) revealed that the identified intermediates had lower toxicity compared to intact TC. A rice seed germination test further confirmed that the NiCo(2)O(4) + PMS system effectively degraded TC into low-toxicity or non-toxic products. In conclusion, NiCo(2)O(4) shows promise as a safe and efficient catalyst in advanced oxidation processes (AOPs) for the degradation of organic pollutants.