Olive mill waste water (OMWW) treatment by diafiltration

Abstract

The present work studied the feasibility of diafiltration for processing olive mill waste water (OMWW). An experimental apparatus, consisted of a tubular membrane accommodation module, a controlled temperature raw material stock tank and a positive displacement pump, was developed to investigate the effects of transmembrane pressure, temperature, membrane type and OMWW dilution on diafiltraion flux. Three tubular Ultrafiltration membranes were used, with Molecular Weight Cut Off (MWCO) 8,000, 25,000 and 100,000 Da, respectively. The performance of each one of the three membranes, in terms of UF permeation flux, was studied by using four OMWW:water dilutions (1:2, 1:3, 1:5 and 1:10), at three temperature settings (30, 40 and 60°C). For each one of the 12 respective combination of temperature and dilution setting, six flux measurements at transmembrane pressure values adjusted within the range of 1–6 bars were taken. The experimental results showed that the overall OMWW diafiltration flux, especially in the case of the membranes withMWCO(Daltons) 25,000 and 100,000, was of high magnitude. This fact creates optimism for the commercial follow-up of the process itself by its use as the main component of a promising hybridic scheme for total handling the OMWW pollution problem in an environmentally friendly and sustainable way, according to the EU adopted environmental principle of zero discharge.