Resumo

GARCIA VILLANUEVA, Luis Antonio  e  FERNANDEZ-VILLAGOMEZ, Georgina. Benzene and hydrocarbons profile from the soil light fraction of the environmental liability of the "18 de marzo" ex-refinery, Mexico City. Rev. Int. Contam. Ambient [online]. 2014, vol.30, n.2, pp.201-211. ISSN 0188-4999.

During the 58 years the "18 de Marzo" Refinery, owned by Petróleos Mexicanos (PEMEX), was in operation, its activities of refining, storage and distribution of hydrocarbons produced spills that impacted soil and water and resulted in the emergence of an environmental liability by the time the refinery closed. Remediation has been considered as an alternative to solve the presence of environmental liabilities. Taking into account these factors, the purpose of this research was to measure the mass of contaminants by determining a profile of the mass of soil for benzene and light petroleum fractions (HFL) in the environmental liability of the refinery, prior and after a process of remediation by depths. Mass discharges that were calculated prior to remediation were 10 139 kg for benzene and 437 090 kg for HFL; after remediation, they were 1092 kg for benzene and 34 992 kg for HFL, given a total of 642 samples in 122 profiles and a soil volume of 680 356 m³. The mass of benzene and HFL after remediation is considered at acceptable levels because the sample concentrations do not exceed the maximum permissible limits set by the OMS-138-SEMARNAT/SS-2003 regulation. The applied methodology can be used in large-size sites where environmental liabilities are present and a looming public health risk. The determination of the profile for the mass of soil is an option to follow up verification of the reports and the mitigation measures of the environmental impact, as it is possible to apply profiling prior and after remediation.

Palavras-chave : remediation; polluted soils; benzene; light-fraction hydrocarbons; sensitivity analysis; bulk density; clay.