RCC Bio-Digester Hybrid STP
Anaerobic digestion with zero power input, plus aerobic MBBR polishing
A hybrid of anaerobic digestion and aerobic polishing, built in permanent RCC civil construction. The anaerobic first stage removes a substantial share of the BOD and COD load with zero power input to the biological process, so only the polishing stage needs aeration. This is the lowest-running-cost option we build.
Supplied from 5 KLD to 100 KLD.
Process Flow
How the Anaerobic Stage Works
Stage 3 — Upflow Anaerobic Fixed-Film Reactor
Structured PVC trickling media provides a very large surface area for biomass growth. Sewage flows upward through the media bed, where anaerobic bacteria degrade organic matter without aeration. The reactor achieves substantial BOD and COD reduction while drawing no power for the biological process itself — the single largest operating cost saving in the plant.
Stage 4 — Aerobic MBBR Polishing
Partially treated sewage enters a Moving Bed Biofilm Reactor where floating carriers remain in constant motion through coarse-bubble aeration. Because the anaerobic stage has already removed much of the load, the aeration demand — and therefore the blower size and running cost — is markedly lower than a plant relying on aeration alone.
RCC Bio-Digester vs. Prefabricated Packaged STP
| Parameter | Civil RCC Bio-Digester + MBBR | Typical Prefabricated Packaged STP |
|---|---|---|
| Structural life | 40–50+ years, monolithic RCC | Depends on shell material and installation |
| Power consumption | Low — gravity flow, anaerobic first stage | Relies more on continuous aeration and pumping |
| Treatment stability | Large volumes buffer hydraulic and organic shock | Smaller volumes respond faster to load swings |
| Underground use | Suited to permanent burial, high water table | May need anchoring or anti-buoyancy measures |
| Maintenance access | Spacious compartments, standard equipment | Compact layout, sometimes proprietary parts |
| Expansion | Add civil tanks or process units | May need additional complete modules |
| Lifecycle cost | Lower — durable civil works, low running cost | Lower initial footprint, replacement driven |
Building for the long term?
For permanent sites where lifecycle cost matters more than installation speed, RCC Bio-Digester is usually the better answer.
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