Olive Production

Olive Production

According to Food and Agriculture Organization, the 2017 olives production was around 21 million tonnes of table olives, and about 3 million tonnes of olive oil [1]. There are more than 140 varieties of cultivated olives within 23 olive-growing countries around the world. Roughly around 95% of them are produced by the Mediterranean countries, which are mainly from Spain (6.5 million tonnes), followed by Greece (2.7 million tonnes), Italy (2.6 million tonnes), Turkey (2.1 million tonnes) and Morocco (1.0 million tonnes). They are the main producers of olives and olive oil. In eastern Mediterranean countries, olive groves are the main agricultural plantation. They do have olive orchards too, which are typically small and located in hilly areas. They are difficult to access and expensive to harvest by hand [2].  

 

Due to the high market demand and the increase of olive trees cultivation, the production of olive oil is rising over time. Olives contain very high in vitamin E and also antioxidants. Many studies found that it can protect heart and may help in preventing osteoporosis and cancer. It considered as important resource of essential fatty acids and antioxidants agents in human diet. It is the main fat source used in Mediterranean diet. Not only in diet, it also has been used in cosmetics, pharmaceutical, fuel for traditional lamp and even as anointing oil.

 

Despite from its benefits, we should look into the environmental impact of olive oil production, especially in the Mediterranean countries. In the process of extracting olive oil, a significant amount of water is needed, hence, it can produce huge amounts of olive mill wastewater, especially during olive harvesting season (October-January) [3]. Olive oil extraction mainly generates 2 types of waste streams, which are liquid stream (olive mill wastewater) and solid residue (pomace). It roughly can produce 35kg of solid waste (olive pomace / olive oil cakes/ Olive husks) and 100 litres of liquid waste (olive mill wastewater/ vegetation water) from 100kg of treated olives [4]. 

The amount of processed olives generated in the main olive oil producing countries, such as Spain, generates approximately 4–5 million metric tonnes of waste per year [5]. In numerous olive-growing nations across the world, disposing of solid and liquid waste from olive oil mills is already a serious environmental concern. Spreading solid waste on farmland and storing wastewater in anaerobic ponds pollutes the soil and air tremendously. Incorrect disposal of olive husk and olive mill effluent results in smell and ammonia being emitted into the atmosphere, as well as nitrates and other pollutants being leached into the ground water [6]. 

References

[1] FAOSTAT

[2] Pollution estimation from olive mills wastewater in Jordan 

[3] The effects of olives harvest period and production year on olive mill wastewater properties - evaluation of Pleurotus strains as bioindicators of the effluent's toxicity 

[4] Utilization of Olive Oil and its By-Products for Industrial Applications

[5] Environmental Assessment of Olive Mill Solid Waste Valorization via Anaerobic Digestion Versus Olive Pomace Oil Extraction

[6] Recycling Solid Waste from the Olive Oil Extraction Process