An average olive oil mill generates 3000 m3 of olive washing waste water (OWW) per year. OWW is among the most recalcitrant and polluting industrial wastewaters, mainly due to its high polyphenol concentrations, and cannot therefore be discharged or reused without adequate treatment. OWW is currently managed by the widely extended evaporation ponds, generating uncountable water and soil pollution impacts due to overflow and landfill disposal of sediments, or by conventional water treatment technologies with high energetic consumption and generating by-products (e.g. sludge) with very limited valorization options.
For the last 7 years, BIOT has developed the eco-innovation AlgaPLUS, an olive wastewater treatment reducing Biological Oxygen Demand (BOD) by 95% and Chemical Oxygen Demand (COD) by 85%, thanks to an algal photobioreactor (PBR) coupled to algae biomass valorization as biofertilizer and treated water reuse. The biological actors of AlgaPLUS are up to 13 microalgae and bacteria native from the olive waste water, specialized in degrading pollutants in OWW (nitrates, phosphates, polyphenols) for their metabolism using sunlight. The outcomes of this process are clean water reusable for activities in the mill (washing, machine cleaning, irrigation) or farms nearby (irrigation for ornamentals and food crops) and microalgal-bacterial biomass valorized as biofertilizer combining into a single product the benefits of organic slow release algal fertilizers (macro and micronutrients and phytohormones) and bacterial biofertilizers (Plant Growth Promoters).
The target market for AlgaPLUS is the olive oil production industry in Europe and Mediterranean, with the main end users being cooperative or industrial olive mills especially within the organic olive oil segment. There are 15,000 mills in Europe and Mediterranean countries, with over 95% of the EU production occurring in Spain, Italy and Greece. AlgaPLUS biofertilizer will first target olive tree farmers (2.5 million in EU) spreading afterwards to other Mediterranean crops like greenhouse horticulture, vines, citrus and tropical fruits. In the near future, a fully developed AlgaPLUS technology will be easily transferable toward most agri-food industries generating polyphenol-polluted waste water such as wineries, table olives and cheese production, whereas biomass applications may be extended to aquaculture, human/animal nutrition and cosmetics due to high-value compounds from microalgae.
