Characterization of Olive Waste Ashes as Fertilizers

Abstract

Wet and dry olive cakes are the most important wastes generated when olive oil is produced. In recent years, both olive wastes have been incinerated to produce electricity, and thereby large amounts of fly and bottom ash are generated. In this study, physical, physicochemical, and chemical characteristics of olive waste ashes produced in Andalusian biomass power plants were analyzed to evaluate their suitability for agriculture. High variability among fly and bottom ashes may be ascribed to the origin of the olive waste and the combustion temperature. Waste olive ashes, which contained all particle sizes, showed high values of pH, salinity, water holding capacity, calcium carbonate equivalent, and P, K, Cu, and B contents. In contrast, moderate values were recorded for Ca, Mg, Zn, and Ni. Nitrogen is scarce in olive waste ashes; they thus can only be part of any fertilization strategy.

Harmonising conflicts between science, regulation, perception and environmental impact: The case of soil conditioners from bioenergy

“…Increased soil hydraulic conductivity, but varies with dose, temperature of formation and soil type (Chang et al, 1977;Etiégni and Campbell, 1991;Demeyer et al, 2001;Gupta et al, 2002;Nogales et al, 2011). Water purification Filtration and decomposition of organic wastes Globally, over 80% of P and N used in agriculture is leached out, with detrimental effects for terrestrial and aquatic ecosystems (Agrawal et al, 1999;Schinder, 2006;Galloway et al, 2010;Potter et al, 2010;Cordell et al, 2011). Application to land has shown less potential for loss of nutrients through leaching (Walsh et al, 2012).…”

“…Bottom ash has been found to increase soil water holding capacity and plant available water fractions (Nogales et al, 2011). Regulating services Carbon sequestration and climate regulation…”

Sustainability of using vineyard pruning residues as an energy source: Combustion performances and environmental impact

“…Concerning the possibility of re-using bottom ashes as soil amendments, in Italy there are not guidelines for the application of biomass ashes on agricultural fields. For this reason, trace element content has been compared with limits set in other European countries [52][53][54], such as Austria, Germany, Denmark, Sweden, and Finland (Table 2). For all elements, concentrations in VPR ashes were below all limits set by the aforementioned countries with the exception of Cu for which the amount exceeded limit values of some countries, namely Germany and Austria, but not others.…”

Development of Geopolymer Mortars Using Air-Cooled Blast Furnace Slag and Biomass Bottom Ashes as Fine Aggregates

“…Bottom ash is created on the grate in the boiler's initial combustion chamber, and it presents a higher percentage of unburned biomass. Previous studies have used these bottom ashes in bricks [23,24], cement manufacture [25], road binders [26], geopolymers [27], fine aggregates in mortars [28], fire resistance materials [29], and fertilizers [30], but the percentage of recycling is very low.…”