Abstract

Persulfate activation based on non-radical pathways has unique advantages in wastewater treatment. A precise design for inducing non-radical pathways by regulating the exposed crystal plane of metal oxides was proposed. Manganese dioxide (MnO2) with (310) and (110) as the main exposed planes (310-M and 110-M) were designed and synthesized for inducing different non-radical pathways. The performance of PMS activation by 310-M and 110-M for phenol degradation was investigated. The quenching experiments, EPR tests and premix experiments implied the absence of radical (SO4•- and •OH) in 310-M/PMS and 110-M/PMS systems. Combined with the results of XPS and electrochemical analysis, electron transfer process (ETP) was the dominant mechanism in the 310-M/PMS system, and Mn (III) was the active site for combining with PMS to form the MnO2-PMS* complex with strong oxidation capacity, which directly extracted the electrons from phenol. While in the 110-M/PMS system, the 1O2 oxidation pathway played a major role in phenol degradation. And the 1O2 was proved to originate from the released lattice oxygen and the single electron reduction of O2. In addition, both 310-M and 110-M exhibited high performance on phenol degradation even in the presence of inorganic ions (Cl-, NO3- and SO42-) and humic acid (HA), and showed good stability in five cycle experiments. This study highlights a novel route for precisely inducing non-radical pathways by regulating the exposed crystal planes of metal oxide catalyst on persulfate activation and improving the performance on wastewater treatment.

Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call