scholarly journals AN AUTOMATIC APPARATUS FOR THE DETERMINATION OF OXYGEN CONSUMPTION

1947 ◽  
Vol 169 (3) ◽  
pp. 667-679
Author(s):  
Peter R. Morrison
Keyword(s):  
Oxygen Consumption ◽  
Automatic Apparatus

Quantification of the kinetic differences between communities isolated from completely mixed activated sludge systems operated with or without a selector using a novel respirometric method

1994 ◽  
Vol 30 (11) ◽  
pp. 255-261 ◽  
Author(s):  
Barth F. Smets ◽  
Timothy G. Ellis ◽  
Stephanie Brau ◽  
Richard W. Sanders ◽  
C. P. Leslie Grady
Keyword(s):  
Oxygen Consumption ◽  
Activated Sludge ◽  
Physiological Changes ◽  
Biodegradation Kinetics ◽  
Substrate Removal ◽  
Biomass Yields ◽  
Selection For ◽  
Single Oxygen ◽  
Activated Sludge Systems

This study quantified the kinetic differences in microbial communities isolated from completely mixed activated sludge (CMAS) systems that were operated either with or without an aerobic selector preceding the main reactor. A new respirometric method was employed that allowed the determination of biodegradation kinetics from single oxygen consumption curves, thereby minimizing physiological changes to the examined communities during the assay. Results indicated that increased values for Ks and μmax for acetate, phenol, and 4-chlorophenol degradation were measured in the CMAS system operated with a selector. The biomass yields on acetate, phenol, and 4-chlorophenol were very similar in both systems. These findings indicate that the operation of CMAS systems with aerobic selectors may result in the selection for degrading populations with higher Ks and μmax values for both biogenic and xenobiotic organic compounds, and that substrate storage in the selector only partially contributes to increased substrate removal rates.

scholarly journals The duration of the recovery period following strenuous muscular exercise

1933 ◽  
Vol 113 (783) ◽  
pp. 327-344 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Normal Values ◽  
Recovery Period ◽  
Oxygen Intake ◽  
Respiratory Metabolism ◽  
Carbon Dioxide Output ◽  
Steady Level ◽  
Made In

There are a variety of ways in which the duration of the recovery period after exercise can be determined. The method most frequently employed depends upon observations of the respiratory metabolism. This method has been chosen because the respiratory changes due to exercise can be followed with reasonable ease and accuracy, and because these changes are among the last of the more obvious effects of the exercise to disappear during recovery. In addition, interesting data concerning the effects of exercise on respiratory metabolism can be collected during the determination of the duration of the recovery period when this method is used. In determining the duration of the recovery period by observation of the respiratory metabolism, it is necessary to decide when the carbon dioxide output and oxygen intake have returned to their normal values and are no longer affected by the process of recovery from the exercise. This decision has been made in a variety of ways by different investigators. Some have made one or more pre-exercise determinations of the subject's basal oxygen intake and carbon dioxide output. Recovery was said to be complete when the carbon dioxide output and oxygen consumption returned to these values after exercise. Others found that the oxygen consumption did not return to the pre-exercise level within a reasonable length of time, but remained above normal for several hours. They considered that recovery was complete when the carbon dioxide output and oxygen intake returned to a steady level after exercise, even if the level was not the same as that before exercise.

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