Iron Removal by Rotating Contact Reactor

摘要

Feasibility assessment was made of using a rotating contact reactor to remove iron (Fe(II) from water. Total soluble iron was determined using the Hach-Ferrozine method. The study was conducted in two phases: (1) determination of Fe(II) removal kinetics for the reactor at various flow rates, and (2) evaluation of the effect of disc surface area on overall Fe(II) removal. Hydraulic detention times less than fifty minutes reduced the percent removal of Fe(II) (from about 99%), according to a first-order (linear) relationship between Fe(II) removal and contactor stage detention time (slope: 2.13/minute). The rotating contactor could achieve 96-99% removal of total iron from a ferrous iron feed stream having a concentration up to 28 milligrams per liter. With eleven or six rotating discs, 99% Fe(II) removal was obtained; but this declined to 81% with all discs removed. Since stabilization of the rotating contactor after changing the flow rate was achieved in such short times (one day or less) relative to times required for biological systems (5-6 days), the oxidation and removal of Fe(II) was probably due to physiochemical activity. Rotation of the discs promotes aeration and mixing, and increases the efficiency of Fe(II) removal.