Co-composting of Olive Mill Waste and Wine-Processing Waste: An Application of Compost as Soil Amendment

Abstract

In order to decrease the environmental harm produced by the agro industries’ wastes’, an investigation of the co-composting of olive mill waste (olive mill wastewater (OMW), olive mill sludge (OMS)) and wine by-products (grape marc and winery wastewater) was done. Three aerated windrows of variable compositions were performed; these windrows differ in terms of their initial composition and the liquid used for their humidification; OMW and wastewater winery were used for humidification to replace water for windrow moistening. Moreover, the main physicochemical parameters (temperature, pH, electrical conductivity, and C/N) were monitored to evaluate the co-composting process. The latter lasted around three months. The elaborated composts were characterized by low C/N ratio, and they were rich in fertilizing and nutriment elements and of low heavy metal contents. The humidification of the windrows with OMW showed effectiveness in improving the windrows temperature, reflected by the high temperatures monitored during the composting process in comparison with the windrow humidified with winery wastewater. Furthermore, a longer thermophilic phase was held in windrows carrying OMS. The valorization of the produced composts for soil amendment significantly improved the soil fertility. Indeed, field experiments showed an increase in radish yield by 10%, the composts were harmless and did not have any phytotoxic effect on radish growth.

Microbial Resources as a Tool for Enhancing Sustainability in Winemaking

“…In particular, grape marc [141,142] and branches have been composted, separately or together [143], showing beneficial results. Quite recently, wine by-products utilization by co-composting with olive mill wastewater was also proposed with promising results [144]. This represents an affordable and useful tool for both grape growers and winemakers, as the reutilization of residues produced by winemaking-related activities can lead to obtain a compost that can be reintroduced in the vineyard from where the plant biomass came from [143,145].…”

Smart Agricultural Waste Management in Traditional Mediterranean Crops

“…The direct incorporation of this waste could cause serious environmental problems if it is uncontrollably and excessively added to the soil. Consequently, its treatment is crucial before being used for agricultural purposes (Majbar et al 2018). In recent years, the notion of integrated waste management has emerged, which is applied to reduce waste at its origin even before being incorporated into the waste stream.…”

“…Their results reveal an improvement in the chemical and physicochemical properties of the soil, mainly fertilizing elements such as calcium, magnesium, nitrogen, potassium, and phosphorus; and a greater production was harvested compared to manure fertilizer. Majbar et al (2018) analyzed the use of compost produced with residues of olive oil and wine processing for fertilizing the soil of radish crops. Their study reveals a significant improvement in the fertility of the soil; an increase of 10% in radish yields; and that the compost was inoffensive and had no phytotoxic effects.…”

“…The management of agricultural residues and the agro-food industries related to woody crops has important repercussions for the environment, human health, and life in general (Félix et al 2017). In Morocco, for example, the industrial sector generates more than 1.2 million tonnes of waste per year, of which the agro-food industry represents 67% (Majbar et al 2018). Therefore, one of the main challenges is waste management, both of crops and processed fruit (Ferreira et al 2013).…”

“…In some regions, this led to large areas of land containing considerable amounts of decomposing waste which pose a significant risk for water courses and the air (Siles et al 2010). However, the high content of organic material of these sub-products means that they can be used to improve the fertility of the soil (Majbar et al 2018). The objective of this study is to highlight the current situation of the management of the waste generated by MTPCs and the utilization and reuse alternatives that are being put into practice, particularly on the farm level.…”