Low-pressure membrane barrier that removes colloids, bacteria and suspended solids ahead of RO or NF, quantified by membrane area, TMP and flux condition.
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- Available
Media Filtration MMF
Granular-bed filtration that removes suspended solids ahead of a membrane, sized here from design flow, filtration rate and bed geometry.
Overview
Granular-bed filtration that removes suspended solids ahead of a membrane, sized here from design flow, filtration rate and bed geometry.
How it works
Separation mechanism and feed window. Handles raw waters carrying suspended solids, colloids and organic colour. It is a barrier for particle load, not for dissolved salt, and it is not a disinfection step.
What the process produces. A filtered stream at the design filtration rate. Filtrate quality is not a design output here; turbidity and SDI are site test results.
Energy. Gravity-driven. Head loss across the bed is the energy consideration.
Process sequence
Where this technology normally sits in a treatment train. The steps either side of it are documented in the Library as separate entries.
- Raw water intake
- Media filtration (MMF)
- Antiscalant dosing
- Primary separation (RO)
Typical applications
- Seawater and brackish pretreatment ahead of reverse osmosis
- Clarification of surface water before high-pressure membrane stages
- Well water with elevated suspended solids
Main equipment
- Filter vessel
- Media bed
- Backwash system
- Freeboard and underdrain
Key design parameters
The parameters an engineer actually sets, and why each one drives the design. EngiMetric does not assume any of them.
| Parameter | Why it matters |
|---|---|
| Design flow | Sets the required filter area. |
| Filtration rate | The primary area driver; higher rates mean more area or more units. |
| Bed depth and effective size | Determines media volume and the head-loss profile. |
| Filtrate recovery | Sets how much flow reaches the next stage and therefore its duty. |
Advantages
- Cheap, robust and widely understood.
- Handles variable raw-water quality without complex control.
- Very low energy demand compared with pressure-driven barriers.
Limitations
- Does not remove dissolved salt or hardness.
- Head-loss estimate in EngiMetric is a screening value and must be checked against manufacturer media data.
- Requires backwash capacity and a defined waste route.
Engineering considerations
- A required per-unit duty flow is an allocation from plant demand, not a tested yield.
- Freeboard and backwash rate determine the peak instantaneous flow, which is usually above the average design flow.
Status and EngiMetric support
Industry maturity and commercial status describe the technology itself. EngiMetric support and quantitative modeling describe what this platform does with it — and those two are read from the engineering registry at build time, so they cannot drift from the code.
- Engineering maturity
- Mature How established the technology is in the industry. Not an EngiMetric claim.
- Commercial status
- Established Where the technology sits in the market. Not an EngiMetric claim.
- EngiMetric support
- Active No execution-registry entry exists, so no support is claimed.
- Design engine
- Yes Whether the Plant Designer can carry this as a configured process step.
- Quantitative modeling
- Partial No engine exists, so EngiMetric states no figure for this technology.
Related tools
Every tool below exists and is live. EngiMetric does not duplicate a formula here — the calculation lives in the tool, and this page links to it.
- Filter Sizing Calculator Filter area, unit count, media volume and screening head loss.
- RO Antiscalant & Chemical Dosing Calculator Antiscalant active mass and product volume for the following stage.
Design this as a plant
Available as a configured treatment-train step with a stated net filtrate recovery. Its filtrate flow sets the duty of every downstream stage.
Configurable in the Plant Designer as an ordered treatment-train step. Its duty, mass balance and equipment requirements are computed from the inputs you state, not assumed.
Sources and references
- Filtration rate and bed geometry — Supplied by the engineer; no universal value is assumed.
EngiMetric does not publish a bibliography of external literature for catalogued technologies. Where a figure is required, it is entered by the engineer from a datasheet or a published reference, and it is labelled as an input.