|
USD – Odor
Scrubber Testing And Analysis
The Union Sanitary District (USD) uses 17 individual mist scrubbers
at the plant site to scrub virtually all the air emissions from
the plant. Sodium hypochlorite is used as the active agent to
remove the odors in the foul air. Because of the large number
of scrubbers, a centralized compressed air system is used to
deliver air to the scrubber nozzles. Since the compressors were
becoming unreliable and maintenance intensive, USD decided to
design a new compressor system. USD retained WBA to develop design
build documents to replace the existing compressor system. To
minimize the relatively high capital cost of the new compressor
system, WBA and USD stress-tested the scrubbers to determine
the lowest possible air pressure needs of the scrubbers. During
the testing, it was discovered that one of the scrubbers performed
reasonably well with very low air pressure. Consequently, USD
authorized WBA to complete additional testing to analyze the
scrubber performance with nozzles designed to produce a mist
without air. The testing indicated that the liquid-only nozzles
performed well enough such that the compressed air system was
not needed. Because of the significant energy savings of avoiding
use of compressed air, the District decided to retrofit the scrubber
system to operate with liquid-only nozzles, and retained WBA
to complete this design.
USD – Odor
Scrubber Upgrade
The Union Sanitary District (USD) retained WBA to develop design
documents to modify its 17 chlorine mist type scrubbers to use
liquid-only spray nozzles in place of the existing liquid and air
spray nozzles. By eliminating the use of compressed air, the District
avoided the capital cost of replacing its existing maintenance
intensive compressors, and will realize significant savings by
not operating the four 200 hp compressors.
The design consists of developing a distribution system to deliver
the concentrated sodium hypochlorite to all scrubbers, new control
panels to control the addition of concentrated sodium hypochlorite
to each scrubber, and modification to the scrubber nozzles and
feed piping to deliver the sodium hypochlorite solution to the
scrubber ducting.
FSSD – Odor Control Project
The Fairfield Suisun Sewer District was interested in controlling
odors from their intermediate clarifiers. WBA performed an evaluation
of the sources of odors, including flux chamber sampling of the
water surface as well as evaluation of the upstream processes.
Possible solutions included liquid phase treatment and/or covering
and venting the clarifiers. The District chose the option of covering
and venting the clarifiers. WBA proceeded into design, evaluating
the best cover system to meet the District's criteria. Considerations
included operational and maintenance ease and efficiency as well
as adequacy to control the odors. After considering several options,
the District selected a biofilter as the method for treatment of
the foul air. WBA included the biofilter in the
design. Finally, there were several miscellaneous items added to
the work, including improvements to the District's existing biofilters,
drainage improvements, and access improvements.
Air Toxics Hot Spots Compliance
WBA was retained by the Dublin San Ramon Services District, the
Fairfield Suisun Sewer District, the City of Millbrae and the City
of Burlingame to prepare all necessary paperwork and implement
the work necessary for compliance with AB2588—Air Toxics
Hot Spots program. The work included preparing the required Emission
Inventory Plan and Program for each client. Work also included
implementing the emission inventory program by managing the laboratories
doing the sampling and analysis and using the data to estimate
emissions of VOC’s. In some cases no sampling and analysis
was performed and other techniques were used to estimate emissions.
The above projects are representative of our experience in this area.
If you
would like additional information on these, or other projects that
we
have completed, please contact us.
For detailed descriptions
of representative projects in our other areas of expertise,
click below on the category you are interested in:
Recycled Water:
Wastewater:
Water Supply:
Specialized
Areas:
|
