Removal of Detergents from Treated Wastewater by Activated Carbon produced from Olives Crushed Seeds

Abstract

The objective of this study is to study the possibility of removing the residual detergent from the treated wastewater by using the available materials (Olives Crushed Seeds) that resulted from Olive’s mills, which contribute in contaminating the environment. The effluent of treatment plants once treated from pollutants and detergents, it can be directed to either infiltration basins to recharge the aquifer or natural water wadis to revival the natural reserves along these wadis. The infiltrated water will be recovered and reused for irrigation. To achieve this objective, through this research the olives crushed seeds has been carbonized at 500 - 550 oC at inert environment by flowing Nitrogen (300-500 cm3/min) in the rector for 1hour and been activated by microwave with assistance of KOH 1:2 w/w, the resulted AC has a surface area 540 m2/g and ash content of 1.08%. Produced activated carbon has been used in removing detergents from synthetic and real wastewater by adsorption process under different conditions such as adsorption time, initial concentration, pH and adsorbent quantity. It has been found that the removal of LAS from synthetic solution is affected by the contact time positively as in the first 20 hours a 35% of the 10 mg/l concentrated is removed and at the equilibrium (5 days) 98% of the LAS was removed. pH within the range of 5 to 9, has no effect on the percentage removal, Initial concentration within the range of (5 to 25 mg/l) has minimal effect on the removal at equilibrium stage, while at the range greater that 25 to 200 mg/l a serious effect is clear and removal dropped from 98% to 65%. As the adsorbent quantity increases, the percentage of removal increases, however, the amount adsorbed by unit mass decreases. Freundlich and Langmuir Isotherms, are describing the relationship between the amount of LAS adsorbed and its equilibrium concentration. Freundlich isotherm describe the relation at the range of 5 to 25 mg/l concentration while Langmuir isotherm describe the relation at the range of 50 to 200 mg/l. Results from the isotherms prove that LAS is a favorable for removal by activated carbon from aqueous solutions. The research proof that detergent can be removed from real wastewater in addition to other substances available at wastewater such as COD and TKN.