Testimonials
“We have found the performance of the system to be quite satisfying and user friendly. We are currently running low level O2 uptake experiments and are impressed with the sensitivity of the instrument.”
“I have found the performance of the Challenge AER-200 to be unmatched. The precise measurement of oxygen consumption, homogenous mass transfer of test materials, and constant and consistent operating temperature have enabled me to obtain extremely accurate test results, particularly as compared to other respirometer systems. I find the Challenge system to be extremely user friendly.”
Sample OUR profiles
With experience, plant operators can learn to “read” the changes in OUR fingerprints to identify the factors affecting plant operation and treatment performance as illustrated in figures above. For example, as F/M ratio increases above a normal level (0.5 in this case), the initial OUR remains relatively constant but the time required to complete the biodegradation increases (Figure A). (see also Pulp Mill Wastewater example). When moderate levels of toxic substances enter a plant, the initial OUR decreases and longer times are required to completely degrade the wastewater constituents (Figure B). In this case, toxicity was simulated by a reduction in the specific substrate uptake rate, q. On the other hand, a low influent BOD load produces a different OUR curve than does the influx of a toxic substance as shown in Figure C. Figures B an C also show how toxic substances can reduce the rate of biodegradation until un-degraded wastewater constituents reach the discharge point of the aeration basin. In effect, toxic substances “push” wastewater constituents through the plant until effluent quality suffers.