Treatment of Olive Oil Waste Waters

Abstract

Olive oil production is well distributed among the Mediterranean countries. Different levels of processing technology and different industrial organizations co-exist. The production cycle is seasonal and usually concentrated in the fall-early winter period. The pollution characteristics of this industry are peculiar because the flow rates are relatively small while the pollutant load is extremely high and difficult to abate because of the inherent characteristics of low pH and high concentrations of suspended matter, organic matter and lack of nutrients. The free disposal of such waste waters into the environment, though fairly common practice, has disastrous effects on the soil, on aquatic bodies, sewers and on urban waste water treatment plants. Factory specific pre-treatment is too complex and expensive to be realistically adoptable. A territory integrated solution strategy is therefore preferable and a few treatment schemes have here been presented. The recovery and exploitation of the by-products can be justifiable while a realistic consideration of the local realities must be kept in mind. Research is still required to improve and optimize some phases of treatment.

Membrane Filtration of Olive Mill Wastewater and Exploitation of Its Fractions

“…A very low‐cost method that may be applied is the direct land application of OMW. Depending on soil composition and because of the mineral and organics content of the wastes, it may be beneficial for the soil ( Balatsouras, 1997 ; Di Giovacchino et al, 2002 ; Papadimitriou et al, 1997 ; Riffaldi et al, 1993 ; Tamburino et al 1999 ). A method, practiced widely, although illegally, is the disposal of OMW into surface waters, including lakes, rivers, and the sea, with disastrous environmental consequences ( Di Giovacchino et al, 2002 ; Tamburino et al, 1999 ; Tsonis, 1988 ; Tsonis et al, 1989 ).…”

Yeast strains from the endogenous microflora of the olive fliesBactrocera oleae larvae which could degrade the olive oil mill wastewaters polyphenols

“…Olive oil mill wastewater (OMW) is a major pollutant of both terrestrial and aquatic ecosystems in the Mediterranean region (Mendia et al, 1986;Servis, 1986;Moreno et al, 1990). OMW is a dark-coloured, mildly acidic liquid of high conductivity and whose composition varies depending on olive fruit maturity and oil extraction conditions (Ehaliotis et al, 1999).…”

Adaptation and population dynamics of Azotobacter vinelandii during aerobic biological treatment of olive-mill wastewater

“…Due to the high organic and polyphenol content of OMW, its direct disposal may pollute both land and aquatic environments [2,4]. Antibacterial activity [5,6], inhibition of seed germination [7,8] and phytotoxicity to herbage crops [9,10] by OMW have been demonstrated.…”

“…The reduction of the extremely high organic load of OMW to environmentally acceptable levels for disposal in aquatic environments is very difficult even through a combination of aerobic, anaerobic and physico‐chemical treatments [4,11,12]. However, OMW is a pure vegetative by‐product, containing no xenobiotics or heavy metal contaminants and its application to soils of low organic matter content, abundant in the Mediterranean basin, would be a sustainable recycling option, if its toxicity to microorganisms and plants was first eliminated.…”