Greetings Eytan,
A biofilm is an organic layer that, “naturally develops when bacteria attach to
an inert support…Since nutrients tend to concentrate on solid surfaces, a
microorganism saves energy through cell adhesion to a solid surface rather than
by growing unattached and obtaining nutrients randomly from the medium.” Alken-
Murray Corp.
http://www.alken-murray.com/glossarybug.html
Fixed biofilm treatment systems are referred to by the following names:
Fixed Film Reactors,
Fixed Film Bioreactors,
Submerged Fixed-Film Reactors,
Submerged Biological Contactors,
Rotating Biological Contactors, and
Fluidized Fixed Film Reactors.
As far as the naming convention goes, the words Reactor, Bioreactor and
Contactor are synonyms, while Fixed-Film and Biological also have similar
meanings. Regardless of the name all systems remove material from the influent
as a biofilm is formed.
While not an emerging technology, the use of biofilm systems to treat
wastewater is not yet commonplace.
Vendors of fixed biofilm wastewater treatment systems
Lantec Products makes the CSCF (Continuous Self-Cleaning Fixed Film) Bioreactor.
http://www.lantecp.com/cscf/CSCFworks.htm
COPA Limited (based in the UK) makes a Rotating Biological Contactor.
http://www.copa.co.uk/New_copa/products/rbc.asp
US Filter Envirex makes a Rotating Biological Contactor (RBC) and a Submerged
Biological Contactor (SBC).
http://www.usfilterenvirex.com/products/wastewater/biological.html
Tuke and Bell Limited (based in the UK) makes a Rotating Biological Contactor.
http://www.tukeandbell.co.uk/pages/rbc/default.htm
Clean TeQ (based in Australia) makes the BioTeQ Compact Submerged Fixed-Film
Reactor.
http://www.acenz.com/fixed-film_reactor/
Hydroxyl Wastewater Systems makes a Fluidized Fixed Film Reactor (F3R)
http://www.hydroxyl.com/ww_03.htm
ABL Environmental Consultants Limited (based in Canada) makes a Fixed Film
Reactor.
http://www.ablenvironmental.com/prod/prod_ffr.htm
Locations of installed of fixed biofilm wastewater treatment systems
City of Glenwood Springs Wastewater Treatment Facility in Glenwood Springs, CO
Rotating Biological Contactors are installed in the facility, which was
designed to treat 2.3 million gallons of wastewater per day. Photos of the
Rotating Biological Contactors can be found at the site.
http://www.ci.glenwood-springs.co.us/depts/waste/waste7.html
Fharney-Keedy Home & Village WWTP in Boonsboro, MD
A GeoForm Fixed-Film Bio-Process was installed by Sloan Equipment Sales
Company, Inc. to treat a 50,000 gpd System.
Photos of the installation can be found at
http://www.sloanequip.com/installa.htm
The WWTP in Queen Anne's County, MD
A GeoForm, Inc. Geo-Reactor was installed by Sloan Equipment Sales Company.
Photos of the installation can be found at
http://www.sloanequip.com/installa.htm
The WWTP in City of Delran, New Jersey
U.S. Filter/DAVCO supplied and installed a 2.5 MGD biological nutrient removal
system as an expansion to an existing system.
The WWTP in Cuernavaca, Mexico
In 1994 U.S. Filter designed, built and operated a wastewater treatment plant
for the city. The system treats wastewater at a rate of 13.8 million gallons
per day and is designed for a population service area of 550,000.
Treatment Success/Problems
I was unable to find detailed information on the success of any specific
installed systems. However, I did find the following general information on
the advantages and disadvantages of fixed biofilm treatment systems. The data
is from the
Wastewater Treatment Process Alternatives Guide prepared by Commonwealth
Technology, Inc.
http://www.ctienv.com/wwtguide.html
On the plus side:
For specifically non-rotating contactors the systems can handle heavy loads and
variable conditions.
The process is Stable process.
The equipment has a small footprint.
For reactors without moving parts, low operator attention required.
On the minus side:
The treatment systems are generally suited to only small or medium sized
plants.
An additional process is required for sludge stabilization.
Installation costs are generally high.
In Rotating Biological Contactors specifically, the process is very sensitive
to overloading and septic wastewater.
Additional Info
Microorganisms in Activated Sludge and Biofilm Processes, Edited by R. Pujol
This looks like a good book to check out.
Biological Wastewater Treatment, 2nd edition, revised and expanded by C. P.
Leslie Grady, Jr., Glen T. Daigger, Henry C. Lim.
This also looks like a good book to check out.
See the EPA’s “Development Document for the CWT Point Source Category,” Chapter
8 – Wastewater Treatment Technologies, Section 8.2.3 - Biological Treatment,
Subsection 8.2.3.2 - Attached Growth Biological Treatment Systems for
additional information on biofilm treatment systems.
http://www.epa.gov/ost/guide/cwt/final/develop/ch8.pdf
Google Searches
://www.google.com/search?q=wastewater+treatment+biofilm+glossary
://www.google.com/search?q=wastewater+treatment+biofilm+fixed+vendors
://www.google.com/search?q=wastewater+treatment+biofilm+vendors
://www.google.com/search?q=attached+growth+biomass
://www.google.com/search?q=attached+growth+biomass+wastewater+vendor
://www.google.com/search?q=attached+growth+biomass+wastewater
://www.google.com/search?q=Fixed+Film+Reactor
://www.google.com/search?q=Rotating+Biological+Contactor
://www.google.com/search?q=Bioreactor |
Clarification of Answer by
bunny2-ga
on
02 May 2002 17:09 PDT
Eytan,
I have consolidated below those portions of the first answer, which
specifically address moving bed reactors.
According to the Wastewater Treatment Process Alternatives Guide
prepared by Commonwealth Technology, Inc. (referenced in the initial
answer) in a “moving-bed Biofilm Reactor…wastewater…flows through a
tank that contains small polyethylene biofilm elements suspended in
the wastewater…The elements are retained in the tank by a screen.”
Wastewater Treatment Process Alternatives Guide prepared by
Commonwealth Technology, Inc.
http://www.ctienv.com/wwtguide.html
From the list of vendors in the original answer, the following provide
moving-bed systems. I’ve included an excerpt from the applicable web
sites referenced above.
Lantec Products makes the CSCF (Continuous Self-Cleaning Fixed Film)
Bioreactor.
http://www.lantecp.com/cscf/CSCFworks.htm
In the CCSF, “waste water is aerated and mixed by an air-lift system
in a reactor vessel packed with specially designed polypropylene media
which breaks the air stream into fine bubbles for efficient oxygen
transfer.”
Hydroxyl Wastewater Systems makes a Fluidized Fixed Film Reactor (F3R)
http://www.hydroxyl.com/ww_03.htm
“In the F3R tanks and reactors," the proprietary biofilm media is
suspended in the wastewater. "The media and return sludge is [sic]
subjected to an aeration process for maximum oxygen and mass transfer.
The result is a very high rate of Biochemical Oxygen Demand (BOD)
reduction per volume.” Their internet site also provides a nice
diagram of the F3R.
ABL Environmental Consultants Limited (based in Canada) makes a Fixed
Film Reactor.
http://www.ablenvironmental.com/prod/prod_ffr.htm
“In the Fixed Film Reactor, plastic media is used in a series of tanks
as a base on which to grow bacteria. The aeration system encourages
the bed of media to gently roll in the tanks so that the wastewater
and media are evenly distributed. The sequential tank arrangement
prevents short circuiting of the wastewater and the loading gradient
(high loading in the first stage and low loading in the last stage)
promotes nitrification.” This process appears to be the most similar
to the Kladnes system you mentioned in your clarification request.
A listing of locations where the Kladnes moving bed reactor has been
installed, can be found at http://kaldnes.com/ref.html
I hope that this information clarifies the initial answer. If you
seek additional data from that provided above, please go back to the
main Google Answers page and submit your more specific question.
Good luck treating wastewater!
Bunny2
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