The Production of activated carbon from local palm-date pits for pollution removal process

Abstract

The Kingdom of Saudi Arabia is one of the leading countries engaged in planting several millions of palm-date trees. Huge quantities of date pits are generated as wastes once dates are eaten. The generated pits can be reused to produce activated carbon that can be used for treating polluted water. The importance of this lies on utilizing the generated waste, which is the palmdate pits, in the form of activated carbon as a medium for wastewater treatment purposes. Thus, it will have an advantage from environmental and economical aspects. The production of activated carbon appears to be one of the most important phases of this study. Different permutation-combinations were investigated to achieve an activated carbon with optimum physical characteristics. This part of the study involved three steps: boiling, soaking and a combined step of carbonization and activation of pits. The produced AC was tested against methylene blue (MB). This test has been conducted to check the ability of the produced activated carbon (24-hr and 12-hr acid soaked pits) in order to remove the pollutants. The experiment lasted for 12 days for both the 24-hr and 12-hr acid soaked pits compared to the commercial activated carbon, which lasted for 35 days. To investigate the pollutant removal efficiencies of the produced activated carbon, an experiment was performed by allowing an unchlorinated secondary effluent to pass through three columns, each filled with different types of activated carbon (i.e. 24-hr acid soaked pits, 12-hr acid soaked pits and commercial activated carbon). The experimental run continued for a period of seventeen days. All three columns were run simultaneously. The run was terminated when the breakthrough was reached. The samples taken from all ports were analyzed for pH and TOC on a daily basis, whereas the Total Coli-forms and the BOD were monitored on alternate days only. The BOD and TOC average removals in the 24-hr acid soaked pits, 12-hr acid soaked pits and the commercial activated carbon were 71%, 69% and 73% respectively. With regard to total coli-forms, very good removal rates were achieved in al columns packed with the three types of carbon in the first few days. However, the removal rates decreased signaling the breakthrough conditions. In conducting the present study, one of the objectives was to statistically determine the significance of activated carbon types (24-hr acid soaked pits, 12-hr acid soaked pits and commercial activated carbon) and the depth of the ports within each column (bottom, 5-cm and 10-cm) in terms of the removal of various pollutants from wastewater. The statistical analysis of the data confirmed that both the activated carbon types and the ports depth had significant effect on organics removal, whereas only the activated carbon types were found to have significant effect on the removal of total coli-forms considering 8% level of significance.