Removal of Hydrocarbon from Sludge of Diesel Storage Tanks by Semnan Zeolite

Disposal of storage tanks’ sludges due to the high concentration of hydrocarbon involved in them and environmental hazards are a major concerns in oil depots. In this study, reducing concentration of hydrocarbon in petroleum sludge by applying a low cost absorption was investigated. For this purpose, natural zeolite of Semnan zone was applied. In the first stage, modification of the zeolite surface was performed by different acids and the modified zeolites efficiencies were studied. According to obtained results, modification of zeolite surface improves hydrocarbon adsorption, so that HCl-modified zeolite provides maximum adsorption. In the second stage, the influence of physical and chemical parameters on the process was studied using Taguchi methods at two levels. The results show that contact time, the amount of adsorption and temperature are effective on the adsorption process. In the last stage, adsorption isotherm of process was examined, and it was found that the hydrocarbon adsorption on the modified zeolite follows the Temkin isotherm. Finally, the results of this study show that hydrocarbon concentration of sludge can be reduced to 83% using just 0.28 gr of low cost zeolite per 1 gr of sludge.