Teores semitotais de metais pesados na fração orgânica de solos da região de Ibiapaba, Ceará

• Ano de defesa: 2020
• Autor(a) principal: Barbosa, Francisco Luan Almeida
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Palavras-chave em Português: Poluição; Elementos traço; Fracionamento da MOS
• Link de acesso: http://www.repositorio.ufc.br/handle/riufc/56229

In the Ibiapaba-CE region, agriculture is prominent in the cultivation of flowers. In these, the use of pesticides is common, contributing with the addition of heavy metals to the soil, present in the molecular composition or in impurities of the products. The objective was to study the dynamics of heavy metals resulting from the use of pesticides in the organic fraction in soils, with contrasting textures, from the region of Ibiapaba, CE. Four areas were selected, two areas cultivated with flowers in sandy texture soil (A1) and another with clay texture (A2) and their respective areas of native forest (MN1) and (MN2), and soil samples were collected in the layers of 0-10 and 10-20 cm. The chemical and physical fractionation of the MOS was carried out, obtaining the fractions humine+mineral (H+M), humic acid (AH), fulvic acid (AF), particulate organic matter (MOP) and organic matter associated with minerals (MOAM). The levels of total organic carbon (TOC) and C in the fractions of MOS were determined and the determination of Fe, Zn and Cu present in the different fractions. The results were analyzed using descriptive statistics and multivariate methods, such as principal component analysis(PCA) and cluster analysis (CA). In A2, higher levels of TOC were observed when compared to MN2, only in the 0-10 cm layer. In A1, the TOC levels do not show any significant difference when compared to MN1, in any of the layers. The contents of COT and C in humic substances were higher in A2, except for C-HU in 10-20 cm, in relation to MN2, due to the addition of organic residues in large quantities, and a lesser soil turnover in the system. of cultivation. The levels of Fe, Zn and Cu in area A2, present higher concentrations in relation to their respective native forest (MN2) and sandy soil (A1), and that the chemical fraction (H + M) and the physical fraction (MOAM) are responsible for the greater adsorption of heavy metals in the soil. It was concluded that the concentration of heavy metals from pesticides in soils was altered due to the higher levels of MOS and the clay fraction, in A2, in comparison with A1 and that the fractions that most contributed to the adsorption of metals in the soil were to the fractions H + M and MOAM.