title: Anaerobic digestion challenge of raw olive mill wastewater.
abstract: Olive mill wastewater (OMW) was digested in its original composition (100% v/v) in an anaerobic hybrid. High concentrations (54-55 kg COD m(-3)), acid pH (5.0) and lack of alkalinity and nitrogen are some OMW adverse characteristics. Loads of 8 kg COD m(-3) d(-1) provided 3.7-3.8 m3 biogas m(-3) d(-1) (63-64% CH4) and 81-82% COD removal. An effluent with basic pH (8.1) and high alkalinity was obtained. A good performance was also observed with weekly load shocks (2.7-4.1, 8.4-10.4 kg COD m(-3) d(-1)) by introducing piggery effluent and OMW alternately. Biogas of 3.0-3.4 m3 m(-3) d(-1) (63-69% CH4) was reached. Developed biomass (350 days) was neither affected by raw OMW nor by organic shocks. Through the effluents complementarity concept, a stable process able of degrading the original OMW alone was obtained. Unlike what is referred, OMW is an energy resource through anaerobiosis without additional expenses to correct it or decrease its concentration/toxicity.
authors: Bioenergy Unit, National Laboratory of Energy and Geology I.P. (LNEG), Estrada Paço do Lumiar 22, 1649-038 Lisboa, Portugal. margarida.sampaio@lneg.pt
authors: M A
authors: MA
authors: Sampaio
authors: M R
authors: MR
authors: Gonçalves
authors: I P
authors: IP
authors: Marques
mesh_terms: D000383:Agriculture / Q000379:methods; D000693:Anaerobiosis; D000818:Animals; D019149:Bioreactors; D001709:Biotechnology / Q000379:methods; D002625:Chemistry, Organic / Q000379:methods; D005740:Gases; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D008372:Manure; D031658:Olea; D019800:Phenol / Q000737:chemistry; D013552:Swine; D013696:Temperature; D013997:Time Factors; D014874:Water Pollutants, Chemical; D018508:Water Purification / Q000379:methods*
chemical_list: D005740:Gases; D007220:Industrial Waste; D008372:Manure; D014874:Water Pollutants, Chemical; D019800:Phenol