Biodegradability of organic compounds in coal conversion wastewater

Biodegradability of twelve organic compounds found in coal liquefaction wastewater was examined by using acclimated activated sludge. The compounds tested were phenol, three isomers of cresol, cyclohexanol, 3, 5-xylenol, aniline, ο-toluidine, pyridine, α-picoline, quinoline and pyrrole. The results are as follows : 1) The limit concentration of each compounds for biodegradation were determined. The limit concentrations ranged from 100mg·l-1 (ο-toluidine and 3, 5-xylenol) to 4000mg·l-1 (pyridine). 2) The limit concentration of a compound in the presense of other one became lower than that of the compound alone. Namely, the additive effects of inhibition were seemed to exist. 3) The activated sludge acclimated to a high concentration of a compound obtained higher resistivity to a certain degree.