What does it mean when the dissolved oxygen rate of the test (DOURT) is greater than the baseline rate of respiration (DOURs)?
Depending upon the homogeneity of the contaminants within the sample, areas of low organic levels may even experience some enhancement of biological oxygen uptake activity. At concentration of samples where there is no toxic effect upon the microbial oxygen uptake rate, uptake rates greater than the baseline rate (DOURs) are sometimes experienced. These enhanced rates are represented as negative inhibition values and usually indicate the presence of certain readily degradable compounds which the “POLYTOX” bacteria can immediately utilize as a good source, thereby increasing cellular metabolic activity and the uptake of dissolved oxygen.
