Related Experiment Video
Updated: Aug 10, 2026
Aerobic Biodegradation Testing of Materials Using a Natural Marine Seawater Inoculum and Closed Loop Respirometer
Published on: October 24, 2025
Precision determination for the specific oxygen uptake rate (SOUR) method used for biological stability evaluation of
B Scaglia1, F G Erriquens, G Gigliotti
1Dipartimento di Produzione Vegetale, Università degli Studi di Milano, Via Celoria, 20133 Milano, Italy.
Abstract:
This work represents the first attempt to evaluate the precision of the specific oxygen uptake rate method expressed in terms of repeatability (r) and reproducibility limits (R). Three laboratories were involved in an inter-laboratory test for the validation of respiration analyses on six biomass samples (three composts and three biostabilized products) having different degrees of biological stability. Both the maximum specific oxygen uptake rate peak (SOUR) and the cumulative oxygen demand after 12 h (OD(12)) and 20 h (OD(20)) of respiration test were investigated. Precisions expressed as the relative standard deviation were in the range of 9-41%. Linear regressions found for r and R, versus OD(12) and OD(20), enabled derivation of precision values (r and R) for all respirometric levels within the operating range. The OD(12) and OD(20) indices were found to be more adequate to indicate biological stability since they were less influenced by random errors than the SOUR index.
