Filter Basics
Suspended Solids Removal Methods: Screens, Media Filters, Separators, and Cartridges
Compare common suspended solids removal methods for industrial water, including screen filters, media filters, separators, cartridges, and staged filtration.
Suspended solids removal is not one technology. It is a design problem that can be solved with screens, media filters, hydrocyclones, bag filters, cartridge filters, membranes, settling, or staged combinations. The right method depends on particle size, density, shape, concentration, flow rate, and how clean the water needs to be after treatment.[1][2]
Screen filters work well when a defined opening size can protect downstream equipment. Media filters can be useful when particles benefit from depth filtration. Hydrocyclones are strongest when the problem is heavier sand or grit. Cartridge and membrane systems can polish finer particles, but they should usually be protected from heavy solids loading upstream.[3][4]
- Method
- Screen filtration
- Best use
- Defined particle cutoff and equipment protection
- Limit
- Can blind quickly with heavy biological or fibrous material
- Method
- Media filtration
- Best use
- Fine or mixed suspended solids that benefit from depth filtration
- Limit
- Requires backwash design and more footprint
- Method
- Hydrocyclone
- Best use
- Heavy sand and grit separation
- Limit
- Does not provide a defined micron cutoff
- Method
- Cartridge filtration
- Best use
- Finer polishing and final protection
- Limit
- Replacement elements can load quickly in dirty water
| Method | Best use | Limit |
|---|---|---|
| Screen filtration | Defined particle cutoff and equipment protection | Can blind quickly with heavy biological or fibrous material |
| Media filtration | Fine or mixed suspended solids that benefit from depth filtration | Requires backwash design and more footprint |
| Hydrocyclone | Heavy sand and grit separation | Does not provide a defined micron cutoff |
| Cartridge filtration | Finer polishing and final protection | Replacement elements can load quickly in dirty water |
The most reliable systems often combine methods. Removing heavy grit upstream, using an automatic screen for defined protection, and reserving cartridges or membranes for finer polishing can reduce maintenance and keep each filtration stage working in the range it was designed for.[5][6]
References
- U.S. EPA, Process Design Manual for Suspended Solids Removal: https://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=9101AVYN.TXT
- U.S. EPA, Total Solids: https://archive.epa.gov/water/archive/web/html/vms58.html
- University of Florida IFAS Extension, Screen Filters in Drip Irrigation Systems: https://ask.ifas.ufl.edu/publication/WI009
- U.S. EPA, Membrane Filtration Guidance Manual: https://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=901V0500.TXT
- U.S. Geological Survey, Turbidity and Water: https://www.usgs.gov/water-science-school/science/turbidity-and-water
- World Health Organization, Water Quality and Health: Review of Turbidity: https://www.who.int/publications/i/item/WHO-FWC-WSH-17.01