ANALYSIS OF METALS CONTENTS IN DOWSTREAM AND UPSTREAM SANITARY LANDFILL GROUNDWATER COLLECTED SAMPLES, RIBEIRÃO PRETO, BRAZIL

In Ribeirão Preto (Sao Paulo State, Brazil), a municipal landfill site (MLS) for urban waste disposal has been operating since 1989. It is integrated with the Medical Waste Treatment Plant (Microware System). This study aimed to estimate the metal levels in groundwater samples collected in downstream and upstream groundwater artesian wells of Ribeirão Preto Sanitary Landfill. It was estimated the presence of Ag+, Al3+, Ba2+, Ca2+, Cd2+, Cr°, Cu°, Mg2+, Mn°, Na+, Pb°, Hg°, K+, Se2- e Zn2+ through Espectrophotometric of Atomic Absorption. The points in upstream presented levels of Al3+, Mn°, Pb° and Se2- higher than the standard established by Regulation 518/2004 of the Ministry of Health, of Brazil, while in downstream points the values of Mn° and Pb° were higher than the allowed limits. A study carried out in 2000, which estimated the levels of Cd2+, Cr°, Cu°, Hg°, Mn°, Pb° and Zn2+ in the MLS area demonstrated Mn° and Pb° levels above the limits allowed by oficial regulations, in soil and sewage. However, groundwater samples collected in 2000 were not contaminated. The results obtained in the present study showed the need to adopt measures to protect the groundwater at the Sanitary Landfill Site Area, considering the detected levels of some metals that can affected the quality of the groundwater.