This work evaluated the level of heavy metals contamination of a sanitary landfill area in Belo Horizonte, Minas Gerais, Brazil. This landfill is situated at the edge of the BR-040 highway, and is close to the Belo Horizonte-Contagem borderline. Samples of free-of-waste soils and soils covered by urban waste of different ages were analyzed by physical and chemical means. The same analysis was performed on superficial and underground water samples, and leachate samples. The physical analyses included textural, mineralogical, and micro-morphological analyses. Chemical analyses determined the cationic change capacity of the different soils. Several ways of metal retention in the soils were investigated by sequencial extraction procedures in the following fractions: (1) total fraction, (2) exchanged fraction, (3) bound to organic matter fraction, (4) bound to Fe oxides fraction, and (5) bound to Mn oxides fraction using samples from 07 soil profiles, and 02 trenches that were opened in the waste pile. Nine samples were taken, including leachate samples for water analysis. Physical and chemical analyses of the soils allowed the understanding of the mobility of the heavy metals, and their dispersion in the profiles. The sanitary landfill area is essentially composed of young soils of acid pH, and clayey to clayey loamy sandy texture. The mineralogy of these soils is composed by minerals from acid rocks (gneiss) and basic rocks (gabbro and micro gabbro). Kaolinite is the main minerals of the clay fraction. These studies show that the superficial layers of soil retain part of the heavy metals that come from solid waste piles. In addition, superficial and underground waters in the sanitary landfill are contaminated by organic and inorganic compounds.
sanitary landfill; heavy metals and organics substances contamination; water and soils contamination in sanitary landfill
