Patent ID: 8157995

Claim:
An ex-situ system for treating contaminant-containing water, the system comprising: a first treatment zone comprising a reducing agent adapted to reduce the oxidation-reduction potential of contaminant-containing water flowing therethrough, wherein the first treatment zone comprises an iron-containing media present in an amount of less than about 10 wt % of the first treatment zone, wherein the treatment zone comprises a pH of at least about 5, wherein said first treatment zone is capable of reducing the oxidation-reduction potential of the contaminant-containing water to not greater than about 0 mV, and restricting Fe 3+ and iron hydroxide production; and a second treatment zone downstream of the first treatment zone, the second treatment zone comprising at least 50 wt % zero valent iron for removing at least a portion of contaminants contained in the contaminant-containing water; wherein said second treatment zone is capable of corroding zero valent iron into Fe 2+ using the contaminant-containing water, forming precipitates from the Fe 2+ and contaminants of the contaminant-containing water, and removing precipitates from the water at a hydraulic loading of about 0.5 gpm/ft 2 .