Avaliação de HPA e BTEX no solo e água subterrânea, em postos de revenda de combustíveis: estudo de caso na cidade de Natal -RN

摘要

The retail fuel stations are partially or potentially polluters and generators ofenvironmental accidents, potentially causing contamination of underground andsurface water bodies, soil and air. Leaks in fuel retail stations´ underground storagesystems are often detected in Brazil and around the world. Monoaromatichydrocarbons, BTEX (benzene, toluene, ethylbenzene and xylenes) and polycyclicaromatic hydrocarbons (PAHs) are an indication of the presence of contamination dueto its high toxicity. This paper presents a case study of contamination in a Fuel RetailStation by petroleum derivative products in the city of Natal. For identification andquantification of the hydrocarbons, EPA analytical methods were used. The values ofbenzene quantified by EPA method 8021b CG-PID/FID, ranged from 1.164 to 4.503mg.Kg-1 in soil samples, and from 12.10 to 27,639 μg.L-1 in underground watersamples. Among the PAHs, naphthalene and anthracene showed the most significantresults in soil samples, 0.420 to 15.46 mg.Kg-1 and 0.110 to 0,970 mg.Kg-1,respectively. In underground water samples, the results for Naphthalene variedbetween 0.759 and 614.7 μg.L-1. PAHs were quantified by EPA Method 8270 for GCMS.All of the results for the chemical analysis were compared with the values for theCONAMA 420/2009 resolution. The results for benzene (27,639 μg.L-1) showed levelshighly above the recommended by the CONAMA 420 resolution, wherein themaximum permissible for underground water is 5 μg.L-1. This is a worrying factor,since underground water makes up 70% of the city of Natal´s water supply