Multi-media Filtration (MMF)

Mit Water manufactures multi-media filtration systems as a cost-effective pre-treatment step for seawater and brackish water desalination. MMF removes suspended solids and reduces turbidity in raw seawater before it reaches downstream cartridge filters and RO membranes, extending filter life and protecting membrane elements from particulate fouling.

Working Principle

Raw seawater flows downward through a pressure vessel containing multiple layers of granular media. Coarse, lighter anthracite on top captures larger particles while finer, denser sand and garnet in lower layers remove progressively smaller particulates. After filtration, the water typically has turbidity below 1 NTU and SDI15 below 5, making it suitable for cartridge filter and RO feed.

System Features

Our MMF systems include epoxy-coated carbon steel or FRP pressure vessels, multi-layer filter media, automatic backwash valves, and PLC control. Inline coagulant dosing is provided to enhance filtration performance during high-turbidity events. Duplex or triplex configurations allow continuous operation during backwash cycles.

MMF is a reliable pre-treatment for seawater and other water sources:

  • Seawater desalination pre-treatment (before cartridge filters)
  • Brackish water RO pre-treatment
  • Surface water treatment for drinking water production
  • Industrial cooling water filtration
  • Aquaculture intake water treatment
  • Produced water treatment for oil and gas

Technical Parameters

Flow Rate10 to 300 m3/h per vessel
Filtration Velocity8 to 15 m/h
Inlet TurbidityUp to 30 NTU (seawater)
Outlet TurbidityBelow 1 NTU
Vessel MaterialEpoxy-coated carbon steel or FRP
Media LayersAnthracite, silica sand, garnet
SDI15 (after MMF)Below 5
Backwash Rate35 to 50 m/h