title: Harmonisation of chemical and biological process in development of a hybrid technology for treatment of recalcitrant metalworking fluid.
abstract: Disposal of operationally exhausted metalworking fluids (MWFs) is enormously challenging. In this study the feasibility of employing a sequential Fenton-biological oxidation for the treatment of recalcitrant components of MWF wastewater was investigated. A statistical experimental design was employed to address Fenton reagent (H₂O₂, Fe²⁺) dose optimisation which ensured minimal concentrations of the reagents, thus making the treatment environmentally less toxic to subsequent biological steps and economically viable. This was achieved by employing a five-level-two-variable central composite experimental design. The results demonstrated that Fenton pre-treatment of the MWF effluent greatly improved biodegradability index (BOD₅)/COD increased from 0.160 to 0.538) with a synchronous lowering in the toxicity of the wastewater, making the recalcitrant component more amenable to subsequent biological treatment. An overall decrease of 92% and 86% in chemical oxygen demand (COD) and total organic carbon (TOC), respectively, was achieved by the two-step treatment method developed.
authors.affiliation: Department of Engineering Science, University of Oxford, Parks Road, Oxford OX13PJ, UK.
authors.forename: Sheeja
authors.initials: S
authors.lastname: Jagadevan
authors.forename: Peter
authors.initials: P
authors.lastname: Dobson
authors.forename: Ian P
authors.initials: IP
authors.lastname: Thompson
mesh_terms: D001673:Biodegradation, Environmental; D057919:Biological Oxygen Demand Analysis; D006861:Hydrogen Peroxide / Q000378:metabolism*; D007501:Iron / Q000378:metabolism*; D054327:Lubricants / Q000032:analysis / Q000378:metabolism* / Q000633:toxicity; D008669:Metallurgy; D010084:Oxidation-Reduction; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism* / Q000633:toxicity; D018508:Water Purification / Q000379:methods*
chemical_list: C045076:Fenton's reagent; D054327:Lubricants; D014874:Water Pollutants, Chemical; D006861:Hydrogen Peroxide; D007501:Iron