UASB - Upflow Anaerobic Sludge
Blanket Process/ Reactors
Upflow anaerobic sludge blanket (UASB)
technology, normally termed as UASB reactor, is a form of Anaerobic
Digester for Wastewater Treatment.
Anaerobic Granular Sludge Bed Technology is widely
used in wastewater treatment and UASB is a proven process and
becoming more and more popular for high strength industrial wastewater
because of its economic advantages.
UASB Reactor Schematic
UASB uses an anaerobic process whilst forming a blanket of granular
sludge and suspended in the tank. Wastewater flows upwards through
the blanket and is processed by the anaerobic microorganisms.
The upward flow combined with the settling action of gravity suspends
the blanket with the aid of flocculants. The blanket begins to
reach maturity at around 3 months. Small sludge granules begin
to form whose surface area is covered in aggregations of bacteria.
In the absence of any support matrix, the flow conditions creates
a selective environment in which only those microorganisms, capable
of attaching to each other, survive and proliferate. Eventually
the aggregates form into dense compact biofilms referred to as
UASB Reactor Process Flow Diagram
A typical process flow diagram of a wastewater treatment plant
utilizing the UASB reactor is shown above. Depending on the influent
strength and the quality requirement for the final effluent, the
effluent from the UASB reactor usually requires some kind of post-treatment.