Abstract
Phthalate esters, such as di-2-ethyl hexyl phthalate (DEHP) and di-n-butyl phthalate (DBP), were efficiently removed from wastewater by inoculating viable cells of Nocardia erythropolis, a bacterium capable of rapidly degrading phthalate esters, in activated sludge. When the wastewater containing 1500ppm of DEHP was treated with the activated sludge inoculated with Nocardia erythropolis, the DEHP was found to be removed at a rate of 98.2% in 1 day and to be gas-chromatographically free on and after the 3rd day. Activated sludges, in particular, when high concentration of substances was used, were efficiently prevented from deflocculation of sludge by inoculation of Nocardia erythropolis, and moreover, the deflocked sludge was restored and recovered by the addition of Nocardia erythropolis.