A previously developed biosensor for fast estimation of short-term biochemical oxygen demand (BODst) was used for
off-line monitoring of intermediate products from the initial step of an anaerobic process in laboratory scale. Good
agreement was generally achieved between the results from the biosensor method and the conventional 5-day test except for samples with high content of organic polymers. During the period of agreement between the measurement
principles, good correlation was achieved between the biogas production rate and the organic loading rate. The results
from this study demonstrate that BODst can be a successful monitoring parameter to achieve a better process control.