Aerobic biofiltration to treat liquid and gaseous effluents
By Irene Hassas,
Filter Innovations Inc.
Increasingly stringent
effluent regulations,
limited treatment
infrastructure and
widespread public concern
have led to an
increase in the development
of various treatment
methods. Organic bed
biofiltration has achieved
success in the treatment of
liquid and gaseous effluent
of farms, slaughterhouses,
compost and landfill
leachates, and food
processing industries, as
well as small communities and municipalities.
The Biosor™ organic medium biofiltration
system is a slow filtration process
using a fixed biofilm. Biofiltration on
the organic support of the system consists
of a fixed process of slow filtration
with biofilm. Primarily, the biofilter is a
reservoir containing a patented multilayer
of organic filteration material of
low particle size distribution.
Hydraulic feed of the
biofilter is done by gravity
percolation. Counter-current
air injection maintains
oxygen contribution.
The process treats organic
charges, nitrogen, and
pathogens effectively, and
eliminates the majority of
pollutants and odours contained
in domestic and
most organic wastewater
effluent.
Volaille Giannone Inc.’s poultry
slaughterhouse.
The principle behind
the bio-filtration process
is based on the multi-layer organic
structure of media. Biosor media performs
both as a natural resin capable of
treating several types of pollutants and
as support for various microorganisms
capable of degrading contaminants.
These pollutants are degraded to CO2
and H2O by the microbial activity. In
fact microorganisms are given the
responsibility to treat the wastewater
and to transform it into water and
odourless gas.
The process reduces the polluting
loads by more than 95% along with the
obnoxious odours. It is very simple to
operate continuously for years and the
treatment efficiency is not affected by
load variation, even if the operation is
discontinued for a period of time. Low
maintenance and minimal operating
attention as well as minimal requirement
for biomass sludge management are contributing
factors in reducing the operational
as well as maintenance costs.
Product History
The technology was developed by
the Centre de Recherche Industrielle
du Québec (CRIQ) as part of an ongoing
environmental research program
for the treatment and valorization of
residuals. Since the beginning of this
program in 1990, the CRIQ has successfully
commenced 14 full-scale
projects to validate this technology.
Created in 1969, CRIQ is a leading
source of innovation and expertise in the
areas of manufacturing technologies, the
environment, industrial information and
standardization.
Case Study
Volaille Giannone Inc. has been
applying Biosor to treat the effluents of
its poultry slaughterhouse since July
1999. In 2003, the company expanded
its operation and added two more biofilters.
As a result, the treatment capacity
increased from 300 m3/d to 500 m3/d.
The treatment process consists of a
primary flocculation treatment that
reduces the BOD5 by 50% (from 1500
mg/L to 750 mg/L) and also removes
most of the phosphorous. 90% of contaminants
are treated by the first three
biofilters installed in parallel. The second
set consists of two biofilters in parallel
that polish the effluents well below
the discharge limits. The open air biofilters
are solid and secure to walk on, and
there is no odour emission.
During the system operation, only
the alarm system needs to be verified
several times per week and
maintenance consists of cleaning the
distribution systems and verifying
mechanical equipment which only
takes a few hours each time.
Performance
Since the commencement of this
project in 1999, the TSS, BOD5, ammonia
and coliform removal efficiency has
been observed and the poultry effluents
met the discharge limits required by the
environmental authorities.
