Related Experiment Video
Updated: Jan 28, 2026

Measuring the Shape and Size of Activated Sludge Particles Immobilized in Agar with an Open Source Software Pipeline
Published on: January 30, 2019
Tuning of activated sludge in winter based on respirogram profiles under standard and site temperatures
Zhihua Li1, Zhenyu Hang1, Qian Zhang1
1School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Abstract:
Respirograms of activated sludge OURTx and OUR20x were measured under site (T) and standard (20°C) temperatures, respectively, and the predicted standard temperature respirogram OUR20x,cal was also calculated using the Arrhenius equation. These respirogram profiles reveal more information than effluent quality. A decrease of OUR20x is a critical alarm signal for the loss of pollutant removal capacity, and a sudden increase of the predicted value OUR20x,cal is an alarm signal for the unrecoverable deterioration of biomass. The sign of OUR20x-OUR20x,cal can be used for selection of tuning strategies. For example, a negative value of OUR20x-OUR20x,cal indicates that doubling biomass is difficult, thus strategies such as extending the reaction time with limited available biomass is preferred. The findings in this study elucidated the respiration profile of activated sludge under changes of temperature and can be effectively used for the stable operation of Wastewater Treatment Plants under cold temperatures and seasonal variations.
More Related Videos
15:19Development of Sulfidogenic Sludge from Marine Sediments and Trichloroethylene Reduction in an Upflow Anaerobic Sludge Blanket Reactor
Published on: October 15, 2015
06:11Author Spotlight: Advancing Anaerobic Microbiota Research Using a Novel Respirometry Protocol
Published on: April 26, 2024
Related Concept Videos
Measurement: Standard Units
Problem-Solving: Tuning of a Guitar String
The string's wave speed can be regulated by varying the linear density. Tension is the other property that determines the speed of...
Acid–Base Equilibria: Activity-Based Definition of pH
In solutions of very low ionic strength—for example, pure water—the...
Standard Enthalpy of Formation
Standard Electrode Potentials
Temperature Dependence on Reaction Rate
Atoms, molecules, or ions must collide before they can react with each other. Atoms must be close together to form chemical bonds. This premise is the basis for a theory that explains many observations regarding chemical kinetics, including factors affecting reaction rates.
The collision theory is based on the postulates that (i) the reaction rate is proportional to the rate of reactant collisions, (ii) the reacting species collide in an orientation allowing contact between...