Degradation of methyl orange by sodium persulfate activated with zero-valent zinc

•Zn0-activated persulfate is a novel advanced oxidation technology.•MO could be effectively degraded by Zn0-activated persulfate with a high removal of TOC.•Both OH and SO4− contributed to MO degradation.•The optimum concentrations of PS and Zn0 were 71mg/L and 1.3 g/L, respectively.•The highest removal of MO by Zn0-activated PS was realized at pH 5.