WET OXIDATION OF QUINOLINE - INTERMEDIATES AND BY-PRODUCT TOXICITY

The influence of oxygen pressure (0.4 and 2 MPa). reaction time (30 an d 60 min) and temperature (260 and 280 degrees C) on the wet oxidation of quinoline has been studied. The dominant parameters for the decomp osition of quinoline were oxygen pressure and reaction temperature. wh ereas the reaction time was less important within the range studied. N itrifying bacteria were used to measure the inhibition from wet oxidat ive-treated samples to study the effect of the (wet oxidation) reactio n conditions. Wet oxidation made quinoline more toxic to Nitrosomonas. This was observed for Nitrobacter as well if low oxygen pressure or l ong reaction times were used. The reaction products derived from the e xperiment in which quinoline was mostly decomposed were studied with r espect to biological degradation. The results showed that these produc ts were highly digestible under activated sludge treatment. The combin ed wet oxidation and biological treatment of reaction products resulte d in 91% oxidation of the parent compound to CO2 and water. Following combined wet oxidation and biological treatment the sample showed low toxicity towards Nitrosomonas and no toxicity towards Nitrobacter. (C) 1998 Elsevier Science Ltd. All rights reserved.