Olive oil industry wastes

Caputo, A.C. Scchia, E Pelagagge, P M. Disposal of by-products in olive oil industry waste-to-energy solutions. Appl. Therm. Eng. 2003, 23,197-214. 

LLE has traditionally been the technique of choice for extracting biophenols from olive oil industry wastes (OIW), using organic solvents as extractants. 

Hanandeh, A.E., 2015. Energy recovery alternatives for the sustainable management of olive oil industry waste in Australia life cycle assessment. Journal of Cleaner Production 91, 78-88. 

Keywords Wastewaters olive oil industry, clay brick, organic wastes, forming process, physical, mechanical and thermal properties... 

During malaxation, when water is added to olive paste to wash it, tons of waste water (800.000 in Italy only) are produced from the oil industry and discarded. Water soluble compounds are then transfered from olives into waste waters and could be recovered. HPLC analysis of the waste water extract showed the presence of hydroxytyrosol, tyrosol, p-OH benzoic acid, vanillic acid, caffeic acid, oleuropein, verbascoside and other oleuropein derivatives. The extract had powerful antioxidant activity and could represent a cheap source of natural antioxidants to be used to preserve food and cosmetics from fat oxidation and rancidity [51]. 

Taking into account the high amounts of wastewater produced by the process of extraction of olive oil, and their chemical composition, in this study, 22 wt % of olive wastewater (OW) or olive oil wastewater (OOW) was used instead of fresh water (FW) on the stage of compression or extrusion molding. The technological properties of the ceramic bricks with waste were compared with those with added fresh water, hi addition, the results obtained by extrusion and compression will be compared, in order to evaluate whether the waste bricks are attractive for an industrial implementation. The use of these effluents used to mix clays when preparing paste for bricks could provide a solution to an environmental problem. 

Clay was supplied by a clay quarry located in Bailen, Jaen (Spain) and was obtained by mixing three types of raw clay in equal parts red, yellow and black clay. Clay was crushed and ground to yield a powder with a particle size suitable to pass through a 150 pm sieve. The waste, olive wastewater and olive oil wastewater were supplied by a local olive oil extraction plant and used directly without any prior pretreatment. The ceramic paste for the extrusion was prepared by adding fresh water (FW) or residue resulting from olive oil extraction (OW or OOW) to the clay in a mixer. The amoimt of added water in the mixer depends on clay plasticity and on its consistency while performing the extrusion. In the present work 22 wt % of FW, OW or OOW was added to the clay. The same value as used at industrial scale for this kind of clay mixture. Extrusion was carried out in a laboratory Venco extruder. Extruded test pieces were dried at room temperature for about 24 h, and then heated in an oven at 110 °C until constant weight for at least 24 h. 

Therefore, the use of these types of waste is a benefit both on an environmental and economic basis. The main advantage for the olive oil extraction industry is the elimination of... 

The use of waste materials as feedstocks for PHA biosynthesis constitutes a viable strategy for cost-efficient biopolymer production and supports various agro-industrial branches to overcome existing waste disposal problems. The subsequent Table 7.2 provides a compilation of selected carbon-rich waste streams that are reported to be potential feedstocks for microbial PHA production. Such carbon substrates that are of importance for human nutrition, like pure starch or edible oils from olives, soya or palm trees, are not included in this compilation. 

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