Title: Closed Loops and the Nitrogen Cycle
Learner Objectives:
Explain microbial mediated interactions of carbon and nitrogen compounds in natural and constructed environments as applied to closed heating or cooling loops.
Content/Topic Outline:
Presenter:
Amanda Meitz
Presentation Description:
Water treatment in closed loops has become more important as loops are increasingly used as energy recovery/conservation devices. Some buildings or industrial processes may have one or two open recirculating cooling tower loops that interact with multiple chilled or heated closed loops. As we improve green technology and sustainability approaches applied to water treatment, we should be aware of the interaction of the carbon and nitrogen cycles that are so important in natural and constructed environments.
Closed loops have been treated with various compounds over the decades and because they are "closed", residuals of past treatments may remain for long periods. Past treatments may include glycol which has been inhibited with various proprietary chemistries, corrosion inhibitors such as nitrite, molybdate, various forms of organic and inorganic phosphorous, silicate, biocides, formerly chromate, and possibly other approaches.
The nitrogen cycle includes a variety of microbial processes that transform dinitrogen gas to organic nitrogen, organic nitrogen to ammonia, ammonia to nitrite, nitrite to nitrate, oxidized nitrogen to dinitrogen gas and a conversion of ammonia and nitrite to dinitrogen gas. Theses processes are named nitrogen fixation, ammonification, nitrification, denitrification, dissimilatory nitrate reduction to ammonium, anaerobic ammonia oxidation (anamox) and are often confused. Aspects of the nitrogen cyce as applied to closed loops and general management and treatment of closed loops will be discussed.
Presenter Bio:
Amanda Meitz is the owner of Biosolutions, LLC a water and water deposit testing laboratory. She worked with cooling water microbiocides at Nalco Diversified Technologies and predecessor companies. She holds a Bachelors degree in biology from Adrian College and a Master of Science degree in microbiology from Michigan State University.