Degradation of Refractory Organic Compounds in Aqueous Wastes employing a combination of biological and chemical treatments

In this study the removal of refractory organic compounds (ROCs) in Aqueous Wastes (AW) employing a combination of biological and chemical treatment were investigated at Department of Chemical Engineering and Materials Science, University of Cagliari, Italy and Department of Engineering, Oxford University, UK. The main objectives were to stimulate and optimise the degradation of ROCs with efficient removal of them in AW. This project is divided in two sections, a theoretical section which included a brief literature overview and subsequently an experimental section which is divided in two parts. The first part deals with the solubilisation and biodegradation of polycyclic aromatics hydrocarbons. Phenanthrene was selected as model pollutant in this study which was solubilised in synthetic aqueous wastes using the mobility agents like surfactants (Tween80, Triton X100), or organic solvents (Methanol, Acetone, n-Hexane) and aerobic bacteria mixed cultures. The second part deals with the degradation of Metal Working Fluids MWFs in real aqueous wastes employing biological and chemical treatments. Chemical and/or biological treatments are usually used to destroy the refractory compounds. The MWFs aqueous waste were provided by Microbial Solution, Oxford (UK). The systems used for investigation consist of batch reactors using an aerobic mixed pure cultures for biological treatment and oxidants, potassium permanganate KMnO4 and hydrogen peroxide H2O2 for a chemical oxidation treatment. Results show the influence of both the refractory compounds and recalcitrant intermediaries on systems.