**1. Introduction**

172 Olive Germplasm – The Olive Cultivation, Table Olive and Olive Oil Industry in Italy

pp 13.

Vierhuis, E., Servili, M., Baldioli, M., Schols, H.A., Voragen, A.G.J., Montedoro, GF. (2001). Study of the effect of enzyme treatment during the mechanical extraction of olive oil on

phenolic compounds and polysaccharides. *J. Agric. Food Chem*. 3(49): 1218-1223. VV.AA. (2003). *Olea*. Trattato di olivicoltura a cura di Fiorino P., Edagricole Ed. (Bologna). Weichmann, J. (1987). *In Postharvest physiology of vegetables*. Marcel Dekker, Inc. New York.

> Among the Mediterranean countries, Italy results to be the second after the Spain for the olive and olive oil production (FAOSTAT, 2012), with around 1.2 million of olive grove hectares, by 80% displaced in the Italian southern regions (ISTAT, 2010). In the olive oil industry, the oil extraction is carried out in oil mills, which are classified in pressure mills, and in continuous "two" or "three" phases way mills. In all milling typologies, only not over the 20% of processed olives constitute the oil production, while the milling byproducts, wastewater and pomace, represents up to 120% of processed olives. These wastes could constitute a problem for their sustainable disposal as well as a resource for soil C stabilization and sequestration, energy generation or production of value-add compounds for the food, pharmaceutical or cosmetic industries.

> A great part of husks derived by pressure and three phases mills is still destined to the industry for the extraction of residual oil through solvents (n-exane: CH3(CH2)4CH3). The residual defatted pomace is used as fuel in cogenerative processes (heat and electric power generation) or, as well as the two phases mill husks (fluid pomace) and olive mill wastewaters, disposed on soil as amendments, both raw and after composting. In the Mediterranean countries, where soils have frequently problems of organic matter lack, and active desertification processes, the recycle of the olive wastes as amendments should be better and more important to protect the environment being a valid alternative and a useful solution to the problems both of sustainable utilization of byproducts and soil fertility conservation.

> In many experimental trials carried out in many sites, the utilization of olive industry byproducts as organic amendments, raw or stabilized through the aerobic fermentation, frequently showed good agronomic efficiency, in terms of fertility and chemical, physic and microbiological characteristics of the soils as well as crops productivity; generally pointing out some negative effects of fermentable organic matter and better findings using stabilized wastes.

© 2012 Toscano and Montemurro, licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2012 Toscano and Montemurro, licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Althought in literature can be found numerous findings on the influence of raw and composted organic materials on soil fertility and crops growth, only few published studies are focused on influences of waste waters and pomace compost on the soil-plant system, for a sustainable crops production.

Olive Mill By-Products Management 175

residue-resource cycle (Roig et al., 2006). In Table 2 are reported the averages of main chemical WW characteristics, given by several Authors (Aktas et al., 2001; Filidei et al., 2003; Moreno et al., 1987; Paredes et al., 1999; Piperidou et al., 2000; Saviozzi et al., 1991; Vlyssides

> Dry matter (%) 6.75 pH 4.84 EC (dS/m) 8.36 O.M. (g l-1) 55.80 TOC (g l-1) 37.00 TN (g l-1) 0.97 P2O5 (g l-1) 0.56 K2O (g l-1) 4.82 Na (g l-1) 0.25 Ca (g l-1) 0.35 Mg (mg l-1) 121.25 Fe (mg l-1) 81.70 Cu (mg l-1) 3.15 Mn (mg l-1) 6.13 Zn (mg l-1) 6.13 d (g cm3 -1) 1.04 Lipids (g l-1) 6.38 Poliphenols (g l-1) 4.98 Carbohydrates (g l-1) 7.16 COD (g l-1) 124.67 BOD5 (g l-1) 65.00

About the microbiological characterization, the results of different analyses performed on different kind of WW, have individualized 130 species of lipolytic microorganisms (56 Fungi, 22 Yeasts, and 52 Bacteria), cellulolytic Bacteria and pectinolytic Fungi, while not are resulting the nitrificants nor the actinomycetes (Pacifico, 1989; Ramos-Cormenzana, 1986).

For the waste waters treatment have been proposed both physic-chemical and biological processes (Amirante & Di Rienzo, 1993; McNamara et al., 2008; Rozzi & Malpei, 1996; Vigo

Among the first ones, finalized to the volumes reduction, and to the mineralization of


et al., 1996; Vlyssides et al., 2004 – as cited in Roig et al., 2006).

**Table 2.** Average composition of olive mill waste waters.

et al., 1990; Vitolo et al., 1999).

organic compounds, they are:


In this chapter on report the state of the art of the by-products composting, and results of some application of raw and composted olive industry by-products on soil and crops.
