Engineering:Coarse bubble diffuser
A coarse bubble diffuser is a pollution control technology used to aerate and or mix wastewater for sewage treatment.
Description
Application
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However, over the past two decades, coarse bubble diffusers have been used less frequently, primarily due to the ever increasing cost of energy and the availability of more reliable, highly efficient fine bubble diffusers.[1] Manufacturers of diffused aeration systems claim that converting from coarse bubble to fine bubble system should yield a 50 percent energy cost savings.[2] Specifically, in aeration tanks, a system that utilizes coarse bubble diffusers requires 30 to 40 percent more process air than a fine bubble diffused air system to provide the same level of treatment.[3] The exception would be in secondary treatment (or side processing) phases. In these processing tanks, floc particles, sediment and carbonate buildup tend to plug or clog the small air release openings on the fine bubble diffusers. Because of their small air openings, fine bubble diffusers cease to have an advantage. Currently, coarse bubble diffusers are the mainstay solution.
These diffusers are typically made in the shape of a perforated rectangular pipe called a wide band, or a cap of 3 inches (76 mm) in diameter with an elastomeric membrane. Other varieties of coarse bubble diffusers exist, though it is generally accepted that all of them perform similarly with respect to mass oxygen transfer. When comparing disc-shaped diffusers, the majority fail to withstand specific challenges,[4] beyond 1 or 2 years, which include: clogging, blowing off and cracking. Any coarse bubble diffuser that eliminates these problems would deliver a huge cost-savings, not only in product replacement, but in system downtime to facilitate their exchange. This is a motivating factor considered by budget-sensitive operators at municipal waste water treatment processing plants.
See also
- List of waste-water treatment technologies
References
- ↑ "Archived copy". Archived from the original on 2011-07-25. https://web.archive.org/web/20110725095623/http://www.wastewater.com/pdf/101.pdf. Retrieved 2010-05-21.
- ↑ "Archived copy". Archived from the original on 2011-07-25. https://web.archive.org/web/20110725095643/http://www.wastewater.com/pdf/105.pdf. Retrieved 2010-05-21.
- ↑ Fine Bubble Aeration (Report). Wastewater Technology Fact Sheet. Washington, D.C.: U.S. Environmental Protection Agency (EPA). September 1999. EPA 832-F-99-065. https://www3.epa.gov/npdes/pubs/fine.pdf.
- ↑ "Compare FlexCap COARSE BUBBLE DIFFUSERS with other Diaphragm Aeration Diffusers | Guaranteed for 25 YEARS". Archived from the original on 2011-03-18. https://web.archive.org/web/20110318140607/http://www.coarsebubblediffuser.com/compare-diffuser-differences.html. Retrieved 2011-03-16.
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