Qualidade ambiental do solo no lixão desativado de Cidade Nova, Natal-RN

Abstract

The lack of technical criteria, as well as measures to protect the environment and public health, associated with the exponential generation of waste composed by a diversity of raw material, mainly petroleum based, makes the landfill a potential source of contamination. Even so, the city of Natal has inappropriately sent all types of waste (hazardous and non-hazardous) produced within its limits, for more than three decades, to the Cidade Nova dumping ground. Therefore, the present study aimed to verify if the irregular disposition of solid waste in the Cidade Nova dumping ground is causing degradation of the soil quality of the area. Soil samples were collected in the landfill area and in native forest as a benchmark of quality. In the analyzes are included physical attributes (particle density, bulk density, particle size distribution and total porosity), chemical attributes (pH, K+, Na+, Ca2+, Mg2+ and Al3+ exchangeable, potential acidity, available phosphorus, CEC, base saturation and total nitrogen), as well as the total concentrations of heavy metals (Mn, Pb, Zn, Cr and Ba). The studied environments are distinguished in relation to the granulometric composition, due to the use of different substrate in the coverage of the residues. In addition, they showed good saturation per base, but CEC and potential acidity were low. The native forest had a higher content of organic matter than the dump. The metals presented concentrations lower than the values of preemption of the current norm, even in the dump being evidenced more Pb and Zn than in the native forest. Both environments showed inadequate waste disposal characteristics. However, it was found that the dump has caused changes in the natural characteristics of the soil, which in turn has acted as a diffuse source of contamination.