That sweet scent in the air? No, it’s not the perfume of a passing cyclist, it’s the new misting machines wafting over vanilla from a Mississippi wastewater treatment plant.
While odour control of hydrogen sulfide and volatile organics at wastewater treatment plants has long been a public concern, the practical application of masking that smell with scents such as vanilla hasn’t appeared to penetrate the Canadian market on any significant level.
Last week, the Associated Press picked up an article by Jackson County, Mississippi-based broadcaster WLOX about the Pascagoula-Moss Point wastewater plant’s new scent misters. What do they do? Two dozen of the machines simply blow vanilla mist into the air for 19 hours of each day from 5 a.m. until midnight. The scent is stored in a barrel and fed up through hoses, around to the front of the building. The utility’s management had heard about a plant utilizing the scent system in Gulf Shores, Alabama, so they went to investigate, then decided to buy into the option.
Despite using a biofilter unit, the Mississippi plant had received regular odour complaints over the years. The utility decided to form a “smell team” and used its input, and that from the local community, to select a vanilla-based scent to mask offending odours.
While odour containment or neutralizing are more common for organic compounds that contain sulfur or nitrogen odors detectable by the human nose at low concentrations, masking or deodorization has become a viable option in some public complaint-heavy regions.
The Pascagoula-Moss Point wastewater plant actually won national recognition in 2018 and has received the Mississippi Water Environment Association Most Outstanding Wastewater Treatment Facility award three times, most recently in 2017.
Researchers from the University of British Columbia’s Okanagan campus found that metal salts can be effective at neutralizing WWTP odours.
Other researchers, meanwhile, have decided to focus more on the prevention of odorant formation.