A NW Ohio Community serviced and fully cleaned one of its Anaerobic Digesters in late 2011 / early 2012 as required for maintenance and proper operation. The facility is a trickling filter plant consisting of primary clarifiers, trickling filters and final clarifiers.
The Digester was placed back in service and seeded with anaerobic sludge from the other digester and started back up. It became apparent that a lack of Methanogenic bacteria were in the seed sludge to properly operate the digester at design loadings.
Following startup, the digester experienced Sour conditions. A Sour Digester is often associated with conditions such as organic / volatile solids overloading, low pH and alkalinity. These conditions often coincide with the lack of optimum methanogenic bacteria that convert volatile acids produced by acid forming bacteria into methane gas. As the volatile acids continue to concentrate, the digester becomes sour. Microbial Vitamin Source was added at the recommended rates based on volume and loadings of the digester, which boosted the existing methanogenic bacteria’s metabolism to convert the already abundant volatile fatty acids.
The municipality plans to supplement Microbial Vitamin Source on a maintenance dosage to help maintain optimum methanogenic bacteria health and optimum organic degradation of the sludge from the primary and final clarifiers.
The superintendent is quoted below on the products and technical service provided by IFM.
"Just wanted to pass along the good news, that our digester has turned the corner and producing more methane than we can use. I do believe the vitamin source ended up playing a big part in the turn around. Thanks a lot for all your help."