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.”
Intrinsic Biodegradation Kinetics Of Chemicals

An understanding of the rate of biodegradation kinetics for specific industrial chemicals is useful when evaluating their treatability or their impact on treatment processes. The objective of kinetic assessments usually is to model the biodegradation reactions for specific chemicals using either pure cultures or defined mixed cultures, or natural mixed culture systems such as those that occur in treatment processes. Measurement of the biodegradation kinetics of organic chemicals usually is accomplished by dosing a microbial culture with a defined amount of organic chemical or wastewater followed by monitoring the reactions through measurement of oxygen uptake in aerobic tests or gas production in anoxic and methanogenic tests. Kinetic models are then fit to the oxygen uptake data using non–linear curve–fitting techniques to produce estimates of the kinetic parameters. Examples of intrinsic kinetic tests are shown in Figures A and B. Figure A show data for aniline biodegradation. In this case, sufficient information was available to model the residual soluble COD and the biomass concentrations. Figure B shows data for phenol. In this case, phenol was inhibitory to its own biodegradation until the concentration was reduced to below toxic levels.
