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.”
OUR Fingerprints - Biodegradable Pharmaceutical Wastes
A pharmaceutical company was interested in knowing whether a specific component, MCB, inhibited the biodegradation of other wastewater constituents. A series of respirometer tests was conducted using a Challenge AER-200 respirometer system. Identical mixtures of wastewater and return activated sludge (RAS) plus varying amounts of MCB were placed in each reaction vessel. The OUR fingerprint of this wastewater includes a first peak of about 500mg/L–hr within the first hour of contact that represents the oxidation of highly–biodradable organic constituents.
A second group of readily biodegradable constituents caused a second high OUR peak between one and two hours. The relative positions of OUR curves suggests that this peak represented the biodegradation of the MCB test chemical. This second OUR peak was followed by oxidation of a slowly degrading group of organic constituents that were completely oxidized between five and seven hours of contact. Oxygen uptake between seven and thirteen hours represents the biodegradation of a final group of constituents – possibly nitrification – before the OUR returns to endogenous rates. The fact that the OUR returned to endogenous rates indicates that essentially all the organic constituents of the wastewater were degraded.