Olive Oil Waste Treatment: A Comparative and Critical Presentation of Methods, Advantages & Disadvantages

Abstract

Since olive oil industries were considered responsible for a great amount of pollution there has been a strong need for optimization of olive oil waste treatment systems. The currently employed systems are numerous and fall in the following large categories; bioremediation (ex-situ, in-situ), thermal processes (incineration, pyrolysis, gasification), evaporation, membrance processes, electrolysis, ozonation, digestion, coagulation/flocculation/precipitation, and distillation. Both advantages and disadvantages in conjunction with respective methodology and explicit flow diagrams were presented per waste treatment method. Furthermore, most recent studies were reported and more than twenty-five figures showing mainly the effectiveness of the current waste treatment methods versus time or temperature were displayed. The comparative presentation of the various olive oil waste treatment methodologies showed that though bioremediation stands for the most enviromentally friendly technique, its required longer treatment time in conjuction with its weakness to deal with elemental contaminants makes imperative the employment of a second alternative technique which could either be a membrance process (low energy cost, reliability, reduced capital cost) or a coagulation/flocculation method because of its low cost and high effectiveness. Biogas production appears to be another promising and energy effective waste treatment method. On the other hand, methods like distillation and ozonation (high cost) and electrolysis (experimental level) are unlikely to dominate this field unless their high cost is substantially reduced in the near future.

Ultrasound assisted cleaner alternate emulsification method for oils and fats: tallow emulsion – fatliquor preparation for leather application

“…Studies in this regard pertaining to olive oil (Arvanitoyannis and Kassaveti, 2007;Arvanitoyannis et al, 2007aArvanitoyannis et al, , 2007bVlyssides et al, 2004), castor oil (Sivakumar et al, 2008) and palm oil (Reijnders and Huijbregts, 2008) have been reported earlier. Recently, production of bioparaffins by the catalytic hydrogenation of natural triglycerides (Hancsók et al, 2012) and sustainability and mitigation of greenhouse gases using ethyl beef tallow biofuel in energy generation (Pereira et al, 2012) have been reported.…”

Chemical precipitation of aerobically treated olive mill wastewater

“…An understanding of the variation of pH with addition of fl occulants/coagulants/precipitants is essential because of its effects in the water treatment process [20]. From Fig.…”

Rhizosphere dynamics during phytoremediation of olive mill wastewater

“…However, they both require long treatment times for satisfactory results (Arvanitoyannis et al, 2007;Jarboui et al, 2010). The use of tree-based phytoremediation to treat and dispose OMW may represent a viable in-between option since it allows to stimulate bioremediation at the root level and to accelerate evaporation due to leaf evapotranspiration (Alkorta and Garbisu, 2001).…”