Biodegradation of toluene by an attached biofilm in a rotating biological contactor

A laboratory scale study using a modified rotating biological contactor (RB C) was constructed to assess aerobic treatment of toluene, a typical aromat ic hydrocarbon. The RBC consisted of 72 parallel discs rotating in a reserv oir and was arranged in three stages. i.e. 24 discs oriented in each stage. An artificial wastewater containing toluene was fed to the RBC. inoculated with an enriched culture from petrochemical sewage. The rotation of the di scs and the recycling time ensured good mixing of the bulk liquid and resul ted in a regular biofilm thickness. Toluene removal was measured by COD mea surement and GC. The effect of initial toluene concentration on toluene bio degradation showed a zero order mechanism. Adaptation of the biofilm to tol uene results in higher COD removal at different stages. (C) 2001 Elsevier S cience Ltd. All rights reserved.