Bioparticles consisting of olive mill wastewater (OMW)-adapted bacteria and OMW-polluted soil as carrier– An application in an anaerobic fluidized bed bioreactor

Abstract The world olive oil production represents a very significant sector of the alimentary industry. Nonetheless, the spillages associated to the sector –olive mill wastewater (OMW)– imply serious environmental risks due to their difficult treatments. This study showcases the use of bioparticles from a soil that has repeatedly been contaminated by OMW, to treat water also polluted by OMW. The bacterial biomass that develops overtime within a OMW-polluted course becomes adapted to its conditions and proves effective in its treatment. Water and soil samples were taken from a watercourse that has been suffering from periodic OMW discharges during the last 25 years. Two main factors were identified as the causes of the efficiency of these soils as a means of biological treatment: high concentrations and extended adaptation of active biomass to the pollutants present in the watercourse. The start-up times of the biological processes are reduced since no adaptation period is necessary. This makes it possible to eschew pre-treatment procedures in biological processes. A guide for the design of a continuous flow anaerobic fluidized bed bioreactor (AnFBR) is provided. A stream of 300 m3 d−1 and 5000 mg L−1 COD generates an electrical and thermal energy of 1654 kW h d−1 and 2341 kW h d−1 respectively.