Aerobic Digester Water & Low DO Issues

In the summer, when the water is warm, it’s natural to have low dissolved oxygen.  For every 5 degrees F warmer, the bacteria activity doubles.  When the bacterial activity rises, so does the oxygen demand. When this happens the plants can get low DO filaments that cause sludge bulking and poor settling.

Aerobic digesters can add to that problem.  When water from a digester, aka “funny water”, is brought back up to the head works, it can cause slight to major upsets.  The water and material in digesters are strong in ammonia and fatty acids.  When this water is brought back to the front, it sucks out the DO. Low D.O. can lead to filaments like Type 021N and excess Zoogloea. This typically will happen in the heat of summer. In the winter funny water can cause effluent ammonia levels to rise. It is easily fixed with the addition of VitaStim Dynamic Duo and VitaStim Rebuild.