DMI-65® Catalytic Iron Removal Filter (Sized Unit)

For the DMI-65 catalytic water filtration media, the operational specifications are: a pH range of 5.8 to 8.6, max rated iron of <15 ppm, max rated manganese of <3 ppm, service flow rate of 5–30 m³/m²/hr (2–12 gpm/sq. ft), and a backwash flow rate of 25–40 m³/m²/hr (12–15 gpm/sq. ft).

Max tolerated chlorine is typically 0.1–0.3 ppm residual feed (up to 3.0 ppm max), and dissolved oxygen (DO) requirements are flexible depending on whether chlorine is used.

Operating Parameters & Limits

pH Range: 5.8 to 8.6 (optimal for manganese removal is closer to 7.5–8.0)

Max Rated Iron (Fe): Up to 15 ppm (recommended lower for standard service velocitiesMax Rated Manganese (Mn): Up to 3 ppm

Service Flow Rate: 5 to 30 m³/m²/hr (2 to 12 gpm per square foot) depending on bed depth and metal load

Backwash Flow Rate: 25 to 40 m³/m²/hr (12 to 15 gpm per square foot) to achieve 20% to 50% bed expansion.

Max Tolerated Chlorine: Continuous feed of 0.1 to 0.3 ppm free chlorine residual is required for activation/maintenance; max limit around 3.0 ppm Minimum Dissolved Oxygen (DO): Can operate via chlorine-driven advanced oxidation without DO, but for purely oxygen-driven (chlorine-free) operation, a minimum DO of 4–5 mg/L is recommended.

Min DO / Manganese Reading Nuances: DMI-65 functions catalytically via external oxidants (chlorine or DO). When managing backwash cycles, backwashing should continue until residual manganese in the backwash effluent drops to 0.2 mg/L before returning to service.