In my last post, I covered the differences between acute and chronic toxicity. While acute toxicity rapidly kills or harms your biomass, chronic toxicity tends to be a longer term loss of activity. Instead of an instant kill, chronic toxicity works by growth inhibition. As organism reproduction slows, the desired microbes can start to decrease as a percentage of total biomass. For example, ammonia oxidizing bacteria (AOB) have a very slow growth rate compared to most heterotrophic microbes. If we inhibit this slower growth rate, the AOB population drops resulting in eventual ammonia breakthrough into the effluent.
Since it does not happen instantly, chronic toxicity can sneak up on operators. There has been little way to detect chronic toxicity problems until you had significant microorganism loss or inhibition. However, this post is not all gloom & doom - a new way to monitoring exists that detects chronic toxicity before treatment efficiency falls. The new monitoring technology - Aster Bio's Environmental Genomics - DNA based monitoring.
DNA is present in all organisms and we can use this DNA to identify which organisms are present. Using Environmental Genomics testing, Aster Bio can do a complete microbial census of everything present in MLSS - full sequencing of all DNA present. For routine chronic toxicity testing, we can monitor population of target organisms such as AOB/NOB, sulfur reducing organisms (SRB), and bulking/foaming filaments among other organisms. In fact, we can customize our rapid qPCR tests for any target organism in a wastewater plant.
The advantages of using qPCR testing include:
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.
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