Peroxymonosulfate activation by cobalt–manganese layered double hydroxide for bisphenol A degradation

Abstract

In this paper, CoMn-layered double hydroxide (CoMn-LDH) was synthesized by the co-precipitation method, and it was applied to activate peroxymonosulfate (PMS) for degradation of bisphenol A (BPA). The results showed that CoMn-LDH with regular morphology and high purity was successfully prepared. The results of BPA degradation experiments showed that the oxidation system had high ability to degrade BPA. The degradation efficiency of BPA reached 95.33% after 90 min at room temperature, pH = 7.0, a PMS concentration of 2.0 mmol L⁻¹ and 0.3 g L⁻¹ catalyst. And the removal rate of total organic carbon (TOC), indicating the mineralization degree of BPA, was 55.83% in 90 min. Finally, the catalytic mechanism of the reaction was preliminarily investigated using radical trapping experiments and X-ray photoelectron spectroscopy (XPS). Free radical trapping experiments showed that OH˙ and SO₄˙⁻ radicals were produced in the reaction process, and OH˙ was the main active radical. CoMn-LDH showed excellent stability and reusability in cycling experiments, and had good practical value.