Olive oil mill waste water as a replacement for fresh water in the manufacture of fired clay bricks

Abstract

AbstractThis paper describes the introduction of olive mill wastewater (OMW) to replace fresh water normally used in clay brick manufacture. OMW is recognised as the major agro‐food industry pollutant in the Mediterranean/North African olive‐growing region. The research involved adding OMW to laboratory‐produced clay bricks following the same making procedure used at a collaborating Tunisian brick factory. The samples containing OMW were found to be comparable in forming/extrusion performance to a control product that used fresh water. If introduced at the factory scale, this innovation would allow a substantial volume of OMW to be recycled, saving on the fresh water currently used in the brick‐forming process. During the subsequent brick drying operation, most of the OMW (∼98% water) would be released as vapour. Once in the kiln, the remaining solids in the bricks (calorific value 21–23 MJ kg−1) would liberate additional heat, reducing the gross energy from fossil fuel currently required during firing. Copyright © 2006 Society of Chemical Industry