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Odor Control Technical Information
Solids handling operations and solids holding
facilities are often major sources of odor at wastewater treatment
plants. Hydrogen sulfide and other odorous compounds generated during
primary settling and solids holding are released during solids
processing. For dewatering processes, belt presses in particular are
prone to severe odor problems. Belt press rooms are notorious for
having high hydrogen sulfide concentrations, which can cause corrosion
of equipment and, in some cases, pose a health hazard to workers. This
case study demonstrates that effective, yet economical, odor control
of solids handling operations can be achieved through an integrated
approach combining both liquid-phase and vapor-phase
treatment.
Authors: Gayle P. Van Durme and D. Matt Bond,
Black & Veatch; Timothy Flora, Plant Superintendent, and Charles
Klinger, Laboratory Technician, City of Leavenworth, Kansas,
USA.
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Most of Central Florida withdraws water from the
Floridian Aquifer by means of deep wells. The water that comes from
both the inland fresh water wells and the coastal saline wells is
typically high in total dissolved solids (TDS) and chlorides. Both the
fresh water and saline water supplies usually contain elevated
hydrogen sulfide concentrations. Indian River County is a coastal
community on the East Coast of Central Florida, with Vero Beach its
largest city and county seat. The county owns and operates two reverse
osmosis (RO) plants and wanted to reduce construction and operating
costs for these facilities while effectively removing hydrogen
sulfide.
The county's two RO water production plants blend finished product
water with raw water between a 3:1 and 4:1 ratio. The plants' combined
finished water is stripped of hydrogen sulfide by forced draft
aerators. The off-gas discharge of hydrogen sulfide has resulted in
numerous odor complaints from area neighbors.
To control odors at regional facilities, Indian River County developed
a program to study the various odor control systems to remove the
hydrogen sulfide odor at the plant aerators. The South County RO Plant
had a maximum finished water flow of 7.06 mgd/day with a 4 mg/L
hydrogen sulfide concentration. The hydrogen sulfide load at the
facility aerator is 236 lbs./day.
At the South County Water Treatment Plant, as well as other treatment
facilities, odor complaints had escalated as development has
encroached on the existing public treatment works. With the
development of South County Park and South County Middle School, the
Indian River County School Board insisted on treatment to remove the
hydrogen sulfide odor in the vicinity of the water treatment
plant. The county Utilities Department recognized the need to also
initiate action to comply with pending US Environmental Protection
Agency Clean Air Act legislation.
In 1995, Indian River County Utilities staff began looking at options
for removing hydrogen sulfide from the product water and concentrate
gas stream at the county water treatment plant aerators. The hydrogen
sulfide removal options, the basis for moving forward with
odor-control testing, were as follows:
- In-line oxidation system
- Two-stage wet scrubber system
- Catalytic/adsorptive carbon system
- Ozone dissolution system
Authors: William F. McCain, P.E., Capital
Projects Engineer, Indian River County; Richard L. Johnson, P.E.,
Principal Engineer, Montgomery Watson America, Inc.; Bradford
H. O'Keefe, Water Superintendent, Indian River County.
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this paper, please register with
us.
Controlling odorous emissions has always been
difficult for sewage treatment facilities, particularly for those near
residential areas. But as nearby populations increase and pump
stations transfer more wastewater solids to the plants, odor control
is becoming a bigger challenge. Treatment facilities traditionally
have used activated carbon adsorbers to clean the air. Now, a new type
of activated carbon, catalytic/adsorptive carbon, controls odors
better and costs less.
The principle sources of odor in wastewater operations are septic
wastewater containing hydrogen sulfide (H2S) and other
odorous compounds in the plant's pipelines; industrial wastes
discharged to the sewage collection system; unwashed grit; scum on
primary settling tanks; organically overloaded biological treatment
processes; solids thickening tanks; waste-gas burning operations in
which lower than optimum temperatures are used; chemical mixing
operations; solids incinerators; and digested solids in drying beds or
solids holding basins.
Odors from these sources vary in degree and intensity depending on the
amount of anaerobic decomposition present. Hydrogen sulfide, the most
prevalent source of all odors, often is accompanied by mercaptans,
indole, skatole, amines, fatty acids and other volatile organic
compounds (VOCs). Odor-control systems typically focus on
H2S because of its low odor threshold (0.47 ppb),
predominance as an odorous agent, and ease of analytical
detection.
Authors: Gary Van Stone and Daniel Brooks,
Calgon Carbon Corporation, Pittsburgh, Pennsylvania,
USA.
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this paper, please register with
us.
Efforts to control odors from sewage treatment
facilities are on the rise as residential areas continue to
expand. Historically, odor treatment revolved around adsorption
(activated carbon), absorption (chemical wet scrubbing) and
biotechnology (bio filters). All are effective to some degree when
applied correctly, but each has specific limitations inherent to the
process.
Recent innovations in activated carbon media and system design offer
municipalities new options. Ultimately, a range of
application-specific factors should be considered — flow rate,
contaminant concentration, space requirements, downtime and
maintenance, operational hazards and disposal of spent materials
— before selecting any odor treatment technology.
Authors: Leo P. Zappa, Calgon Carbon
Corporation, Pittsburgh, Pennsylvania, USA.
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this paper, please register with
us.
If you would like to view the complete text of
this paper, please register with
us.
The author shares his experiences of his
organization's search for a suitable odor control system for a
municipal wastewater treatment plant. He provides a comparison of
available technologies and explains the advantages of their final
selection — Calgon Carbon's Phoenix™ system. Safety, process
technology, efficiency, and community satisfaction issues are
addressed.
Authors: John Ritchey, Plant Superintendent,
Newport, Oregon Wastewater Treatment Plant.
Visit the Calgon Carbon Engineered Solutions web site for technical papers and other decision-critical information about our innovative odor control systems, including SweetVent, SweetStreet™, VentSorb®, HighFlow, Phoenix™, Deep Bed OCU, Titan, and Centaur®.
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