Activation of persulfate and hydrogen peroxide by using sulfide-modified nanoscale zero-valent iron for oxidative degradation of sulfamethazine: A comparative study

•SMT removal in S-nZVI/PS system and S-nZVI/H2O2 system was compared.•S-nZVI/H2O2 system shows much stronger oxidative capacity than the S-nZVI/PS system.•S-nZVI/PS system was more susceptible to the molar ratio of Fe/S in S-nZVI.•S-nZVI/PS system has a wider efficient pH range compared with S-nZVI/H2O2 system.•Groundwater components had minor effect on SMT removal by S-nZVI/PS at pH 5–8.