In view of the frequent detection of atrazine (ATZ) in water body

which is a recalcitrant herbicide

zero-valent iron activated peroxymonosulfate (PMS/Fe0) was proposed to remove the ATZ in water. The effects of operation parameters (pH value

initial ATZ concentration

and PMS and Fe0 dosages) on ATZ degradation were investigated. Then the reactive species in PMS/Fe0 system were in-situ identified based on the competitive reactions of nitrobenzene (NB) and ATZ

and the formula for radical production ratio was derived under steady-state assumption. Finally

the degradation of ATZ by PMS/Fe0 was investigated under simulated groundwater condition. Results show that the pseudo-first order rate constant (kobs) of ATZ degradation decreased with increasing pH value and initial ATZ concentration

and increased with increasing Fe0 dosage. While it increased first and then decreased as the PMS dosage increased

reached the maximum at 25 μmol/L PMS. The competition experiment shows that sulfate radical (SO-4·) and hydroxyl radical (·OH) were reactive species in PMS/Fe0 system

and the production ratio of the two radicals was calculated to be 10.5∶1. ATZ degradation efficiency could reach 87% at 0.25 g/L Fe0 and 25 μmol/L PMS under simulated groundwater condition

indicating the prospective performance of PMS/Fe0 under groundwater conditions. The research results can provide theoretical reference for PMS/Fe0 applications in remediation of atrazine-polluted groundwater.