Waste not, want not Processing and washing olives requires huge amounts of water. New technology promises eventually to save up to 90% of the precious liquid in traditionally water-hungry areas. Health © Shutterstock The EU is the most important producer of olives, accounting for 80% of production worldwide. Olive producers are usually SMEs based mainly in rural areas of Greece, Italy and Spain. Often, these rural areas suffer from a water shortage, and washing the many tonnes of olives wastes huge amounts of drinking water. To ensure the sustainability of the sector and meet the growing demands for olive oil globally, a solution must be found to allow for more efficient water use. The EU sponsored the ′Biotechnological recycle of olive mills washing water by microalgae′ (Algatec) project, which aims to diminish the amount of water produced in olive oil mills, reduce wastewater management costs and alleviate the environmental impact of waste. By promoting the reuse of water and offering advanced technologies, the project will also increase the sector's competitiveness and promote jobs in the industry. The project began with extensive laboratory tests and monitoring of the wastewater in order to work out how best to treat it. Project partners undertook lab experiments on microalgae biotechnology to isolate the bacteria and microalgae in wastewater. The next step was to demonstrate if a photobioreactor – equipment to filter out contaminants using light and biological means – was effective in treating the wastewater in question. Initial results were very successful, highlighting the suitability of this low-cost environmentally friendly technology in decontaminating washing water after 30 days. Ongoing experiments are attempting to shorten the time needed, and different pretreatment methods with activated carbon are being combined in the process. This favours the growth of good algae used to combat contaminants and improve treatment efficiency. The new equipment will be tested during the next olive harvest in 2011 and will initially transform at least 10% of the washing water into drinking water. More tests and assessments are needed to ascertain the viability of this promising project. If it succeeds, it could revolutionise wastewater treatment and ensure the ongoing success of the sector.
