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Footprint Matters: AGS–SBR vs Activated Sludge SBR

Footprint is a decisive factor in modern sewage treatment, particularly for decentralised and urban installations. Although both systems operate as SBRs, AGS–SBRs consistently require significantly less space than Activated Sludge SBRs due to fundamental biological differences.

Footprint Is a Function of Biology

Activated Sludge SBRs require larger volumes to maintain sludge age, provide anoxic reaction time, and ensure safe settling. These needs increase tank size and auxiliary infrastructure.

AGS–SBRs achieve multiple biological functions within a single reactor through granular biomass, as explained in Article 7.

Sludge Age vs Biomass Retention

Activated Sludge SBRs depend on long sludge retention times to sustain nitrification. AGS systems retain biomass structurally, allowing higher concentrations in smaller volumes.

readily biodegradable carbon is limited and valuable. Its premature consumption leaves insufficient substrate for denitrification and biological phosphorus removal, resulting in partial BNR or dependence on external carbon dosing.

Elimination of Additional Zones

BNR-oriented Activated Sludge SBRs often need:

  • Larger reactors

  • Conservative settling allowances

  • External or internal anoxic provisions

AGS–SBRs internalise these requirements within the granule.

AGS–SBRs typically achieve 20–40% footprint reduction compared to Activated Sludge SBRs delivering equivalent treatment performance.