The Upflow Anaerobic Sludge Blanket reactor (UASB) was a successful improvement for anaerobic wastewater treatment.

High volumetric loading rates (up to 10–15 kg COD/m³ per day) can be reached on certain wastewater. The UASB reactor is the most commonly used system mainly because of its simplicity and robustness.

Countless references have proven its full scale applicability. BIOTIM^® UASB is one of the most successful anaerobic wastewater treatment technologies.

The reactor can be divided in three different areas

1. the sludge bed,
2. the sludge blanket,
3. the three-phase separator.

By natural selection for well settling sludge, most of the active sludge will be present at the bottom of the reactor. The wastewater is fed at the reactor bottom through a distribution system. While flowing upwards through the dense sludge bed, the organic pollutants are converted into biomass and biogas. This biogas creates a more turbulent area above the sludge bed, called the sludge blanket.

On top of the reactor the three-phase separator first separates the biogas from the sludge-water mixture. Then, because of the lower turbulence, the sludge will begin to settle and return to the sludge blanket. To improve the sludge-water separation, parallel plates can be installed inside the separator to increase the settling surface area.

Applications

One of the most common applications is in the brewery and beverage industry for high loaded wastewater. Also many food industry and chemical wastewaters are successfully treated. The anaerobic system is combined with an aerobic post-treatment (read the section on LUCAS® anaerobic-aerobic).

Advantages

Main advantages of the UASB system are the high COD removal efficiency, high loading capacity, low sludge production, very stable operation and high gas production (energy recovery).

BIOTIM^® UASB, Lutosa - Belgium

BIOTIM® UASB, Ceres Fruit Processors, South Africa	BIOTIM® UASB, Central de Cervejas, Portugal