This document presents information on upflow anaerobic sludge blanket (UASB) reactors. It discusses that the UASB technology was developed in the 1970s to treat industrial and sewage wastewater using anaerobic digestion. The key factors affecting UASB reactor performance are identified as organic loading rate, nutrients, hydraulic retention time, volatile fatty acids, operational temperature, and operational pH. Advantages of UASB reactors include high efficiency, simplicity, flexibility, low space and energy requirements, and low sludge production, while disadvantages include low pathogen/nutrient removal, long start-up times, potential for odors, and need for post-treatment.

1. * LUCKNOW MODEL INSTITUTE OF
TECHNOLOGY AND MANAGEMENT
PRESENTATION ON
UPFLOW ANAEROBIC
SLUDGE BLANKET
REACTOR
SUBMITTED TO: SUBMITTED BY:
SHIVAM SINGH (1448400026)
SANDEEP KUMAR (1448400023)
DANISH IQBAL (1448400009)
ER RIYAZ (1448400022)

2. INTRODUCTION
The UASB technology was developed by
Lettinga and his co-workers in the late
1970’s.
Originally the reactor was designed to
treat industrial waste water but later its
application was extended to treatment of
sewage.
Nowadays, the use of UASB rector is
extensively for the treatment of several
types of waste water, forming a part of the
high rate of anaerobic technology.

3. UASB reactor Setup
The UASB scheme basically consisted of
Influent tank, peristaltic pump, cylindrical
UASB reactor, Gas/liquid/solid separator,
effluent outlet, gas outlet and collection
system. Figure 18.7 showing the basic scheme
of the UASB reactor.

4. UASB Reactor

5. FACTORS AFFECTING PERFORMANCE OF UASB
REACTOR
 Organic Loading Rate
 Nutrients
 Hydraulic Retention Time
 Volatile Fatty Acids
 Operational Temperature
 Operational pH

6. 1. Organic Loading Rate
Organic loading rate (OLR) is an important
parameter that considerably affects the
performance of a UASB reactor. The fluctuations
in organic load depends on the sludge
properties, mixing intensity, SRT (sludge
retention time), HRT (hydraulic retention time),
duration of the variation, bacterial mass and
activity.

7. 2. Nutrients
The growth of anaerobic microorganisms
depends on the availability of the essential
nutrients present in the wastewater.
Deficiency of these nutrients could
negatively affect their growth of microbes
and also the efficiency of the anaerobic
degradation.

8. 3. Hydraulic Retention Time
The hydraulic retention time (HRT) is defined as
the average time that wastewater spends inside
the reactor. HRT is affected by both the flow
rate and composition of wastewater entering
the UASB reactor. High HRT increases the
contact time of wastewater with the sludge and
hence improves the effluent quality and biogas
production rate.

9. Volatile fatty acids are important intermediate
products in the formation of CH4. The right
concentration determines the efficiency of
substrate removal from the reactor. For a typical
reactor, overloading, or sudden variations in HRT
and OLR could cause the accumulation of VFA and
stressful conditions in the reactor during the break
down of complex organic matter.
4. Volatile Fatty Acids

10. Operational temperature is an important
parameter in anaerobic degradation
processes. It determines the dominant
bacterial flora and the growth rates of
microorganisms present in a reactor.
Different species of bacteria can survive at
different temperature ranges.
5. Operational Temperature

11. 6. Operational pH
pH is a very important parameter for an
anaerobic digester as microbes are highly pH
dependent and require suitable conditions of pH
to grow optimally. pH far below or higher than
the required range could cause an accumulation
of acetate, thereby inhibiting the methanogens
and leading to conversion of COD to volatile
acids instead of CH4 production. Therefore,
mostly anaerobic digestion reactors have been
operated at pH of between 6.5–7.5.

12. Block Diagram

13. Advantages
High efficiency
Simplicity
Flexibility
Low space requirement
Low energy consumption
Low sludge production

14. Disadvantages
Low pathogen and nutrient remover
Long Start-up
Possible bad odors
Necessity of post-treatment

15. QUERIES…???

16. Thank You…!