Biological treatment of olive mill wastewater

Otpadne vode prerade maslina nastaju tijekom proizvodnje maslinovog ulja. Godišnja produkcija OMW procjenjuje se na više od 30 milijuna m3. Sastav OMW je vrlo promjenjiv i ovisi o sorti masline, zrelosti ploda, te procesu ekstrakcije (prešanje ili centrifuga). Svojstven težinski sastav OMW je: 83-94% vode, 4-16% organskih spojevai 0,4-2,5% mineralnih soli. OMW je visoko organski opterećena otpadna voda koja sadrži vodu, organske kiseline, polifenole velike molekulske mase poput tanina, antocijana i katehina, koji su odgovorni za crno smeđu boju i toksična svojstva. Zbrinjavanje i obrada otpadne vode prerade maslina je ozbiljan ekološki problem zbog visokog organskog opterećenja, prisutstva polifenola i tanina, visokog udjela suspendiranih tvari i kiselosti. Veliki broj različitih mikroorganizama (arheja, bakterija i gljivica) i procesa (aerobni ili anaerobni bioreaktori, kompostiranje) testirani su za obradu OMW. Aerobne bakterije su bile testirane za uklanjanje fitotoksičnih spojeva iz OMW. Gljivice su se pokazale učinkovite u smanjenju KPK i toksičnosti. Anaerobne konzorcije učinkovito smanjuju KPK, ali su osjetljive na fenole u OMW.Olive Mill Wastewater (OMW) is generated in the production of olive oil. The annual OMW production is estimated to be over 30 x 106 m3. The composition of OMW is very variable and depends on olive variety, the ripeness of the fruit, and the extraction process (press or centrifuge). Typical OMW composition by weight is: 83-94% water, 4-16% organic compounds and 0.4-2.5% mineral salts. OMW is high organic loading effluent which contains water, organic acids, high-molecular-weight polyphenols such as tannins, antocyanins and catechins, which are considered to be responsible for its brownish black colour and toxic properties. Disposal and treatment of olive mill wastewater (OMW) is a serious environmental problem due to its high organic loading, presence of polyphenols and tannins, high content in suspended solids, and acidity. A number of different microorganisms (Archaea, Bacteria and fungi) and processes (aerobic or anaerobic bioreactors, composting) have been tested to treat OMWW. Aerobic bacteria have been tested for removal of phytotoxic compounds from OMWW. Fungi have proven effective at reducing COD and toxicity. Anaerobic consortia can effectively reduce COD, but are sensitive to phenolics in OMWW