Banca de QUALIFICAÇÃO: MARCOS VINICIUS SANTOS PANTOJA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : MARCOS VINICIUS SANTOS PANTOJA
DATE: 26/02/2025
TIME: 10:00
LOCAL: Ufra - Sala virtual
TITLE:

ORGANIC COMPOUNDS AS CONDITIONERS OF CHEMICAL ATTRIBUTES OF BAUXITE MINING OVERWORTH IN THE AMAZON REGION.

KEY WORDS:

Organic waste, degraded areas, bauxite mining.

PAGES: 28
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Ciência do Solo
SPECIALTY: Fertilidade do Solo e Adubação
SUMMARY:

The mining sector plays a fundamental role in the Brazilian economy and society, especially in the state of Pará, which is the second largest producer of minerals in the country. Bauxite production, in particular, is significant in the region, where three of the largest mining operations in the country are located. However, mining has environmental and sociocultural impacts, such as loss of biodiversity and soil degradation. One of the main challenges is dealing with the waste generated by mining. After aluminum extraction, the surface is altered, leaving only a mixture of horizons B and C, called waste rock, which has low availability of nutrients and organic matter. A possible solution to mitigate these impacts is the use of organic compounds as chemical attribute conditioners. The objective of this study is to monitor the transformations in the chemical properties of waste rock from bauxite mining after the incorporation of organic compounds for the formulation of technosol. Additionally, it was evaluated which sources and doses of organic compounds presented greater stability over time. The experimental design is completely randomized with 13 treatments and 7 replicates, totaling 91 experimental units. The experiment was carried out in the Laboratory of Soil Genesis, Morphology and Classification, at the Federal Rural University of the Amazon, with mining waste and organic compounds distributed in 0.5 kg pots, at doses of 5, 10, 20 and 40 t/ha. The experiment is being conducted for six months, with periodic analyses to evaluate changes over time. Biochar was produced from açaí seeds, collected in the region, using the pyrolysis process at 400°C. In addition, organic compost from Ceasa, pruning residue and organic compost from açaí were used. The analyses performed include evaluation of soil fertility, cation exchange capacity, pH and phosphorus adsorption study, in addition to characterization of the residues. In the statistical analysis, the data were subjected to the normality and homogeneity test of residues (Shapiro-Wilk) and after that, the analysis of variance (ANOVA) and comparison of means were performed by the Tucker test at 5%. The açaí seed biochar presented a yield of 46%. Regarding the chemical characterization, the açaí organic compound had the highest ash content (66.34%), providing a greater amount of nutrients, while the biochar presented the lowest content (4.6%) and the highest fixed carbon content (56.57%), giving it greater stability. The content of volatile materials varied among the residues studied, with emphasis on the pruning residue, which presented the highest value (65.6%), while the açaí compound obtained the lowest (25.4%), influencing the emission of gases and the behavior during combustion.

COMMITTEE MEMBERS:
Interna - ***.148.002-** - EDNA SANTOS DE SOUZA - UFRA
Interno - 1552048 - NORBERTO CORNEJO NORONHA
Externo ao Programa - 1279582 - ERIC VICTOR DE OLIVEIRA FERREIRA - UFRA