The reported contributions of magnetite to the abiotic natural attenuation of chlorinated ethenes have generated interest in its potential for soil and groundwater remediation. In this study, we investigated the impact of the two-step sulfidation method on the physicochemical properties and reactivity of magnetite with trichloroethene (TCE). We systematically evaluated the effect of different sulfur precursors (dithionite, thiosulfate, and sulfide) and sulfur-to-iron ([S/Fe]