Abstract
To find a control index of activated sludge, dimethyl disulfide (DMDS) in the mixed liquor of aeration tank was tested. When the activated sludge was cultured at high load of BOD in synthetic wastewater (peptone, glucose), odorous sulfur compound was generated. It was identified as DMDS by gas chromatographmass spectrometer. The amount of DMDS in water could be quantitatively determined by the head space gas chromatographic method. When the condition of activated sludge became worse by increasing the load of BOD, DMDS was detected in the mixed liquor of aeration tank. When the condition of activated sludge was recovered by decreasing the load of BOD to be normal, DMDS was not detected. It was suggested that DMDS could be used as a useful control index for the estimation of the condition of activated sludge, because, DMDS was detected prior to the obvious changes of commonly used indices such as sludge volume index and BOD of effluent.
