engleski

Biological treatment of olive mill wastewater in SBR

Olive industry generates a huge amount of wastewater and other wastes and is a major environmental issue, particularly in Mediterranean areas. The problems mainly arise from the effluent`s high level of pollutants (carbohydrates, proteins, lipids, mono and polyaromatic compounds such as polyphenols) leading to a high chemical oxygen and biological demand, high toxic organic loads and low pH. Untreated olive by-products discharged directly into soil have detrimental effects not only on plant growth and microbial activity but also to the physicochemical properties of soils. A number of processes have been used for olive mill wastewater treatment including lagooning, physio- chemical treatment, electro coagulation, Fenton and Electro Fenton processes. The present study consists of treatment of olive mill wastewater inoculated with municipal activated sludge in SBR. The experiments were conducted in laboratory-scale reactor Armfield W11, with a working volume of 5L and an airflow rate of 1.5 L min-1. Different initial concentrations of activated sludge (3 and 5 g L-1) and different initial concentrations of organic matter in wastewater, expressed as COD concentrations (5 and 10 g L-1) were investigated. The preliminary results show that the ratio of COD/BOD was 1.74 which is less than 2 and as such can be treated biologically. Further, the toxicity impact indeks (TII50) was 313, which shows that this wastewater is extremely toxic. The activated sludge reduced the effluent pollutants (COD, phenols). Value pH influenced on the removal of phenols. The average efficiency of the biological treatment of olive mill wastewater was 89%.

Olive mill wastewater; activated sludge; SBR

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