Determination of appropriate method for estimating of MTBE absorption coefficient by the soil of Tehran oil refinery (Ray city)

Methyl Tertiary-Butyl Ether (MTBE) is one of the gas additives that can be more effective in increasing the octan rating of fuel. EPA (Environmental Protection Agency) has labeled MTBE in carcinogen compounds.This compound can leak into the soil from underground fuel tanks and its chemical and physical properties affords rapid influence.Sorption ability of soil, is so effective in influence of MTBE into the soil and “distribution Coefficient (Kd)” can show this ability. Kd is one of the important effectives that recently lionizes in Environmental Geotechnics and its range is so wide in as much as it can be “0” or “1000” and more; This wide range is important in using numerical models for underground water and contaminant trasformation modeling.In this study, the real value of sorption has been determined by several sorption tests on MTBE and the soil of Ray city and according this value, various isotherm models were studied to find the most accurate model for MTBE and this soil.In this study, all of the tests have done according to ASTM standards.
Finally, it’s concluded that all of studied models are appropriate for calculating Kd but in similar cases,  we can offer foloing models sequently: Dubinin-Radushkevich Model; Langmuir Model; Freundlich Model; Linear Model.