Biochemical
and Biotechnology -
Improved Apparatus for Carrying Out a Bioreaction
Introduction
Wastewater from various industrial
and domestic sources contains many hazardous chemicals,
which have to be treated prior to discharge into natural
streams. Such treatment is done by employing an apparatus
for carrying out bioreaction. The presently used apparatus,
i.e. bioreactors have limitations such as low rates
of bioconversion, non uniform mixing characteristics,
adaptability for varying feed pattern or feed concentration,
etc. In order to overcome these limitations a fluidized
floc bioreactor has been developed. This improved reactor
does not need any solid settling devices and no carrier
material is required for biomass growth.
The bioreactor comprises of a cylindrical
or tapered reactor disposed in a vertical position.
Truncated cones are provided at the upper end and lower
end to act as phase separator and liquid distributor
respectively. An inlet port is provided at the lower
end of the reactor for introduction of wastewater. Outlets
for treated water and gas are provided at the top of
the reactor. The height and the diameter are generally
in the ratio of 5:1 to 30:1. The preferred ratio is
however between 10:1 to 20:1. A number of outlets are
provided at different heights along the vertical length
of the reactor for removal of the flocs. Bio conversion
is brought about by flocs of micro-organisms present
in the reactor The fluid containing the reactants enters
at the inlet preferably with such velocity so that the
flocs are retained in the fluid state. As soon as the
bioconversion progresses, the flocs grow in size and
settle at the bottom of the reactor. In order to maintain
the steady state operation of the bioreactor very large
floc particles are regularly removed from the various
outlets along the height of the reactor.
Special Features:
High rates of bioconversion due to
high concentration of biomass; Excellent mixing characteristics
due to fluidized nature of contents; Steady state of
operation with constant biomass concentration; Steady
state of operation with constant biomass concentration;
Easy control of process because of withdrawal of solids
at the bottom; Clarified liquid from the outlet
Prospective Users:
Domestic and Industrial waste water
treatment plants
Keywords:
Waste water, Treatment, bioreactor
Type of Technology:
Process
Status of IPR Protection:
Indian Patent Application No. 1479/DEL/99
dated 15th January 2001 with title "An Improved
Apparatus for carryingout Bio-reaction"
Status of Development:
Under the sponsorship of Dept. of
Biotechnology, Govt. of India, studies were conducted
in a 40 litre total volume reactor designed and fabricated
in IIT, Delhi. Waste water from various sources like
dairy effluents at different hydraulic and operating
conditions were treated at the rate of 500 litres per
day. Even at a very small hydraulic retention time of
about 2 hours, the COD of the effluent was brought down
from a value of about 1200 mg per litre to less than
100 mg per liter. This was accompanied by production
of biogas containing 65% - 70% methane. The amount of
methane produced was almost 300 titres (STP) per kg.
of COD removed. The treated effluent had excellent sludge
settling and dewatering characteristics also.
Major Equipment & Facilities required:
Reactor volume: 800 litres (approxly);
Floor Area requirement : 4m x 4m
Services offered
by Technology Transfer:
Know how manual including quality
control procedures
Process demonstration
Consultancy
Contact for
more information
The Director
Foundation for Innovation and Technology Transfer
Indian Institute of Technology Delhi
Hauz Khas, New Delhi-110016
Tel : 91-011-26597167, 26857762, 26581013
Fax : 91-011-26851169
E-mail : mdfitt@gmail.com
