Sedimentation and Digestion on Pond Bottoms – An Attempt to Establish a Short-Term Material Balance
Abstract
Sedimentation and digestion have been measured in situ on the bottom of the first (facultative) and the last (maturation) pond of a wastewater stabilization pond system during six periods of one week. Calculated dry solids balances of the ponds bottoms showed that most of the collected solids would have an endogenous origin. Identification of the collected solids by digestion in the laboratory and supplemental in situ measurements in winter, when gas production was low, allowed the conclusion that the collected solids actually were fairly stabilized bottom sediments which are resuspended by the vigorous gas production. The establishment of a short term sedimentation-digestion balance appears to be a practical impossibility on an actively fermenting pond bottom.