Wastewater Treatment Using Activated Carbon Produced from Oil Shale

In recent years, many researchers have expressed interest in wastewater treatment using activated carbon produced from cheap raw materials. In this work, an activated carbo-aluminosilicate (ACS) – supported zero-valent iron (ZVI) composite was produced from Um AL-Rasa oil shale mine and examined to eliminate Chromium (VI) from contaminated water. Activation of raw oil shale fine particles (< 212 μm) was chemically performed using 95 and 5% wt of H2SO4 and HNO3, respectively, as activating agents. The activated material was further treated with caustic soda, named ACS, and modified with fine zero-valent iron particles < 212 μm), called ZVI/ACS composite. Kaolin was added to the composite with the ratio: (50 % wt. light kaolin: 50 % wt. ACS), named as ZVI/ACS/K. The XRD analysis for both composites confirmed iron dispersion at 45°. Adsorption experiments were carried out using the two adsorbents ZVI/ACS & ZVI/ACS/K under different values of pH, and adsorbent dosage. The results indicated that the reduction of Chromium was maximum under the 3 pH value and 2.0 gm amount of ZVI/ACS/K. Furthermore, it was found the removal rate was enhanced by 17% and 24.7% when ZVI/ACS & ZVI/ACS/K adsorbents were used, respectively, compared to that when only ACS adsorbent was used alone. Finally, the dependency of Chromium removal on its initial concentration by ZVI/ACS/K adsorbent was also investigated at two different temperatures of 27° and 50°. The results indicated a decrease in the removal rate of the Chromium as the concentration increased at 27°; however, the removal rate previously enhanced at 50° at all initial concentrations.