SBR

Sequencing Batch Reactors (SBR) or Sequential Batch Reactors are a type of activated sludge process for the treatment of wastewater. SBR reactors treat wastewater such as sewage from communities, municipalities in batches. Oxygen is bubbled through the mixture of wastewater and activated sludge to reduce the organic matter [measured as Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD)]. The treated effluent may be suitable for discharge to surface waters or possibly for use on land.

There are five stages in the treatment process in SBR :

• Fill
• React
• Settle
• Decant
• Idle

First, the inlet valve is opened and the tank is filled, while mixing is provided by mechanical means, but no air is added yet. This stage is also called the anoxic stage. During the second stage, aeration of the mixed liquor is performed by the use of fixed or floating mechanical pumps or by transferring air into fine bubble diffusers fixed to the floor of the tank. No aeration or mixing is provided in the third stage and the settling of suspended solids starts. During the fourth stage, the outlet valve opens and the “clean” supernatant liquor exits the tank.

Advantages

• No moving parts processes like nitrification, organic matter removal, settling, or clarification are carried out sequentially over time in a tank.
• Less footprint, as clarifier is not required.
• Fluctuation is buffered in a pre-equalisation tank, therefore producing consistent treated effluent quality.
• Treated effluent of highest quality BOD < 10, COD < 100 & TSS < 5.
• Can be constructed in the bolted tank, mild steel epoxy paint (MSEP) and civil.

Applications

INDION SBR delivers treated water quality far better than local discharge norms. Ideal for housing complexes, hotels, commercial complexes, industries and institutes (IT parks, hospitals & malls).

The treated water can be discharged or used for cooling tower make-up, gardening, toilet flushing and other low-end applications after suitable post-treatment or disinfection.