Treatment of palm oil mill effluent using evaporation and adsorption techniques

Abstract

The bench scale experiment was carried out with an aim to teat the palm oil mill effluent by utilizing it's physical and chemical characteristics. The raw effluent has a temperature of 80 degree C to 85 degree C, thus by introducing a vacuum of 350mm Hg, the effluent will evaporate without any addition of heat. The vapour produced was then passed through a bed of adsorbent. Four different types of adsorbents were studied in this part namely activated carbon, natural zeolite and synthetic zeolite of the X and A type. The vapour, (before adsorption) when analysed showed a 99% removal of most polluting parameters monitored except for pH, COD and BOD. The effluent was able to be concentrated to as high as 25% solid content from the initial content of 3-5% solids. This will result in a recovery of 80% of the water content and also the POME volume will reduce by the same percentage. The concentrated effluent analysis showed a high content of notrogen, phosphorus and pottasium which can be used as feed material for the making of fertiliser. Next, the adsorption process results indicated that the synthetic zeolite gave a better treatment than that of natural adsorbents.