Three Approaches To Controlling Odor In Wastewater Treatment Ponds

By Joel Bleth, president and CEO, Medora Corporation

Due to their ability to circulate a precise horizontal cross-section of water, long-distance circulators can solve odor problems in equalization ponds, anaerobic ponds, and deep-water industrial ponds.

Solving odor problems in wastewater treatment ponds should begin with a few investigative questions: How was the pond designed? Has the operation of the pond changed over the years? What is the purpose and operational theory of each pond, and have ponds been added or closed? Why are odors apparent on some days and not others? Understanding these “hows” and “whys” will provide clues to successfully solving odor problems in a variety of wastewater treatment plants.

All organic material contains sulfur, a chemical element that is necessary to sustain life. Sulfur in the aerobic digestion process is converted to odorless sulfate in the presence of oxygen. Sulfur in anaerobic digestion becomes sulfide and exists in several forms, from hydrogen sulfide to mercaptins, or thiols. The odors associated with sulfides are equally as diverse, ranging from the smell of garlic to rotten eggs and worse. Wastewater treatment plant operators may rate the odors coming from their plants from mild to offensive, depending on the number of complaints received from nearby residents.