Leopold filter systems are a powerful and reliable solution for municipal wastewater treatment. A Leopold filter is planned based on particular upstream conditions. Each aspect—filter media, filter controls, design parameters—is tuned to achieve maximum filtration efficiency at the longest possible filtration cycles. But more importantly, Leopold filter systems are designed and engineered to meet your permit requirements.
Normal Filter Cycle
- Suspended particulates are removed from water by flowing the water via gravity through filter media at a high rate.
- The solids are removed within the depth of the granular material.
- Filtered water is removed from the filter through an underdrain system.
- Cleaning the filter media is accomplished with an upflow water wash with either full bed fluidization or sub-fluidization depending upon the media.
- Air scour ensures thorough cleaning resulting from higher shear forces in the media bed and abrasion between grains.
- The volume of water above the filter bed increases to just above the edge of the waste gullet. Dirt is dislodged and flushed out of the media, pushed to the surface of the water by the upward flow, and captured via water overflow into the waste gullet.
- Dirty backwash water is evacuated from the filter for recovery.
Features and Benefits
- Deep Bed Filtration
Achieves optimum suspended solids removal due, in part, to more efficient solids storage in the box. Handles wide swings in solids loading while providing long filter runs.
- Downflow Design
Works with gravity, eliminating the need to pump influent through the media, combining reduced power consumption and high filtration rates (6 gpm/sf or more).
- Combined Air/Water Backwash
Superior media cleaning; low backwash water consumption (<2%).
- Flexibility in Filter Design
Not restricted to one type of filter layout based on underdrain design limitations. System can be designed to a variety of site conditions or to existing filter basins.