Combined filter
Three stages in one body: mechanical retention, biological nitrification and sorption “polishing”. For mobile and compact RAS, where water purity and space saving are important.
- steps
- 3–4
- Productivity
- up to 120 m³/h
- Layout
- horizontal/vertical
Replace combined-filter.jpg in the photo of your module.
Comprehensive cleaning in confined spaces
What does the equipment solve?
- Stage 1 - mechanics: micromesh/slit cassette for cutting suspended matter.
- Stage 2 - biophase: MBBR or stationary loading for nitrification.
- Stage 3 - sorption: Charcoal/Zeolite to “polish” color/smell/DOC.
- Stage 4 (optional) — UV/ozone for sanitary stabilization.
- Automatic flushing and removal of sludge without stopping the remaining sections.
Equipment
- Housing PP/stainless with inspection hatches, level and pressure sensors.
- Own section collectors, valve groups and bypass line.
- Control panel: flushing scenarios, schedule, alarms.
- Dosing unit (oxygen/ozone/coal) as needed.
- Interface for connecting to general automation and remote access (optional).
How does it work and what are the options?
The flow passes through successive sections: first a suspension compartment, then the biofilm oxidizes ammonia→nitrite→nitrate, after which sorption removes residual organic fractions and odors. Each section has its own washing mode so that the service does not affect the other stages.
- Guidelines for mechanical filtration speed: 5–15 m/h (according to water quality).
- Filling with MBBR carrier: 30–60% of the section volume, aeration according to DO.
- Sorption: coal in cassettes/columns, replacement schedule according to ΔP/adsorb.
- Inline — horizontal layout, low height, convenient for rooms with limited span.
- Tower — vertical module with a cascade of sections; saves space, gravity drainage of sludge is easier.
- By choice of biophase: MBBR (fluctuation resistant) or fixed load (lower energy consumption).
- Polishing: coal, zeolite or mixed cassette; UV/ozone as a separate unit after sorption.
The final parameters are according to the technical specifications: feed/day, temperature, salinity, required NO₂/NO₃, room dimensions.
Selection and hydraulics
- Initial: flow rate m³/h, turbidity/suspension, feeding (kg/day), TAN/NO₂/color targets.
- Pressure drop (ΔP) by section - calculation for the pump and reserve for the headroom.
- The volume of the biophase is based on TAN (kg/day) and the selected carrier.
- Sorbent - by DOC/smell, with a regeneration/replacement schedule.
Options and integration
- Add. stage: UV or ozonator in trace doses (after sorption).
- Thermal insulation/casing for outdoor installation, drip eliminators.
- Remote monitoring, ΔP/level alarms, flushing logs.
- Arrangement with a drum filter and skimmer in a common path.
Frequently asked questions
When is a combined unit better than separate units?
When space is critical, a quick turnkey installation and a small number of maintenance units are needed. For large RAS it is usually more profitable to space the stages.
How do you know when it's time to rinse?
Increase in ΔP, drop in flow rate, increase in turbidity after mechanics. The panel has thresholds and a schedule for autowashes.