SURVIVAL OF A NONFLOCCULATING BACTERIUM, THIOBACILLUS-THIOPARUS-TK-1,INOCULATED TO ACTIVATED-SLUDGE

The survival of a non-flocculating bacterium inoculated to activated s ludge and the development of the bacterial activity were examined. Thi obacillus thioparus TK-1, which degrades O,O-dimethyl phosphorodithioa te (DMDTP) contained in the wastewater of pesticide manufacturers, sho ws no flocculation property. This strain was inoculated to activated s ludge at the concentration of 5 x 10(7), 10(5) and 10(3) cfu/ml, and a wastewater containing DMDTP was treated with this sludge. No degradat ion was observed for the first 3, 5 and 7 days, respectively. However, after this lag time the activated sludge developed the stable degrada tion activity. The population of the inoculated strain in the activate d sludge decreased at first, but then increased very rapidly up to 10( 8) cfu/ml and remained stable at this level.