Zero valent iron (Fe⁰ ) was used to activate persulfate (PS) to generate SO_－⁴ · and thus to oxidize the 2,4-di-tert-butyl-phenol (DTBP) in water.Then,the degradation of DTBP at various initial Fe⁰ dosage,initial PS concentration,initial pH value and temperature was investigated,and the effects of ultra violet light (UV),Fe⁰ and Fe²⁺ on the degradation were analyzed in a comparative way.The results indicate that (1) the degradation of DTBP accelerates when the Fe⁰ dosage increases from 0. 5 to 4. 0mmol/L,while an inhibition may occur when the dosage reaches 5. 0 mmol/L; (2) the increase in PS concentration from 0. 125 to 0. 500mmol/L in DTBP solution can accelerate the degradation of DTBP,but the degradation velocity firstly decreases and then increases when the PS concentration continuously increases; (3) the velocity of Fe⁰ -catalyzed degradation for DTBP gradually decreases with the increase of the initial pH value; (4) temperature has no obvious effect on the activation of PS in degrading the DTBP in a heat-activated PS system,and only 42% of DTBP is degraded within 60 min at 55 ℃; (5) when the temperature increases from 35 to 45 ℃,the degradation velocity of DTBP decreases slightly in both the heat- activated PS and the Fe 0 /PS systems; and (6) as compared with UV and Fe²⁺ ,Fe 0 performs a consistent catalytic degradation effect on DTBP,and helps to achieve the highest degradation efficiency of 98% within 60 min,also， the Fe⁰ -activated degradation is more economical and environmentally friendly.