Recovery of spent bleaching clay for reuse in water treatment

Abstract

The objective of this research is to reuse spent bleaching clay for treating polluted water, instead of disposing it. The spent bleaching clay is disposed by all palm oil refineries after the completion of crude palm oil bleaching process, which gives negative effects to economy and environment. In this research, three steps are practiced as its experimental methodology to recover the clay, which are the oil extraction from the clay by using alcohol for 1 hour, the excess gum removal from the extracted clay by using hot water for 1 hour and finally burning the clay by using pyrolysis method for half an hour, with the temperature range from 400 0C to 650 0C. The combusted clay was then tested using polluted water from river and lagoon pond as reagent. In this experiment, the untreated spent bleaching clay was used as control, and the distilled water was used as standard pure water. The parameters used for this experiment are the adsorption performance for the clay and the quality of the polluted water. The findings of the experiment were investigated from the pH and ultra-violet spectrometry results obtained from the polluted water; and the output was, the recovered clay neutralizes polluted water (from pH 4.0 to pH 6.5; and from pH 9.0 to pH 7.5; which the safe range of water: 6.5 ?? pH of water ?? 7.5) and decolorizes it (from dirty water to clean colourless water); and improves the quality and usage safety of the polluted water. Thus, the recovered spent bleaching clay is applicable in water supply treatment.