Spirillium or spirochetes are spiral shaped microorganisms that move with a unique cork-screw movement through the sample. Their rapid movement makes then easily observed in water samples.
You often see spirochetes when there are "septic" conditions.
Septicity is produced by anoxic or anaerobic conditions allowing for fermentative respiration. During fermentative resipiration, bacteria produce organic acids as the end product of metabolism.
Spirochetes may also be common with influents containing organic acids (common in brewing, fruit and vegetable processing, winery, etc).
No matter what the source, high levels of organic acids can cause problems with filaments that thrive on the low dissolved oxygen and readily soluble substrate. This is why systems with high influent organic acid loadings often see fewer filament problems with a complete mix reactor or step-feed in plug flow reactors. Another source of organic acids is a long residence time in the primary clarifier or upstream lift stations.
Erik Rumbaugh has been involved in biological waste treatment for over 20 years. He has worked with industrial and municipal wastewater facilities to ensure optimal performance of their treatment systems. He is a founder of Aster Bio (www.asterbio.com) specializing in biological waste treatment.
Click to set custom HTML