Abstract
The mechanism of the formation of dimethyl disulfide (DMDS) in mixed liquor of activated sludge was studied. To find the precursor of DMDS, each sulfur-containing substance (DL-cystine, DL-cysteine, DL-cystathionine, DL-homocysteine, s-adenosyl-L-methionine, s-adenosyl-L-homocysteine, DL-methionine, methylmercaptan and Na2S) was added to the mixed liquor of activated sludge. DMDS was formed from DL-methionine and methylmercaptan. It was found that the activated sludge was necessary for the formation of DMDS from DL-methionine, but not necessary from methylmercaptan. For the formation of DMDS in the mixed liquor of activated sludge, dissolved oxygen (DO) was necessary. It was concluded that methylmercaptan was formed from methionine by activated sludge, and the methylmercaptan changed to DMDS in the presence of DO.
