title: Anaerobic treatment of olive mill wastewater and piggery effluents fermented with Candida tropicalis.
abstract: Olive mill wastewater (OMW) contains high concentrations of phenolic compounds that are inhibitory to many microorganisms making it difficult to treat biologically prior to discharge in waterways. The total mono-cyclic phenol reduction in OMW in this study was carried out by aerobic pre-treatment using the yeast Candida tropicalis in a 18 L batch reactor at 30 degrees C for 12 days followed by anaerobic co-digestion. A COD removal of 62% and a reduction in the total mono-cyclic phenol content by 51% of the mixture was achieved in the aerobic pre-treatment. Pig slurry was added as co-substrate to supplement the low nitrogen levels in the olive mill wastewater. Subsequent anaerobic treatment was carried out in a 20L fixed-bed reactor at 37 degrees C and HRT between 11 and 45 days. After a long start-up period, the OLR was increased from 1.25 to 5 kg COD m(-3)day(-1) during the last 30 days, resulting in subsequent increase in overall COD removal and biogas production, up to maximum values of 85% and 29 L(biogas)L(reactor)(-1)day(-1), respectively. Methane content of the biogas produced from the anaerobic digestion ranged between 65% and 74%.
authors.affiliation: Department of Chemical and Process Engineering, University of Sheffield, Sheffield, UK.
authors.forename: Gregorio
authors.initials: G
authors.lastname: Martinez-Garcia
authors.forename: Anbu Clemensis
authors.initials: AC
authors.lastname: Johnson
authors.forename: Robert T
authors.initials: RT
authors.lastname: Bachmann
authors.forename: Ceri J
authors.initials: CJ
authors.lastname: Williams
authors.forename: Andrea
authors.initials: A
authors.lastname: Burgoyne
authors.forename: Robert G J
authors.initials: RG
authors.lastname: Edyvean
mesh_terms: D000693:Anaerobiosis; D000818:Animals; D001673:Biodegradation, Environmental; D041022:Candida tropicalis / Q000378:metabolism*; D005285:Fermentation; D007220:Industrial Waste; D008697:Methane / Q000032:analysis; D031658:Olea; D013552:Swine; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D007220:Industrial Waste; D008697:Methane