Banca de DEFESA: ROBSON DA COSTA LEITE

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : ROBSON DA COSTA LEITE
DATE: 31/08/2022
TIME: 08:00
LOCAL: Sala do google meet
TITLE:

BAUXITE AND PALM OIL RESIDUES: AGRONOMIC AND ENVIRONMENTAL POTENTIAL FOR THE CONDITIONING OF ACID SOILS

KEY WORDS:

Bayer process, Circular economy, Mining sustainability, Soil conditioners, Waste management

PAGES: 97
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Ciência do Solo
SPECIALTY: Manejo e Conservação do Solo
SUMMARY:

Agribusiness has been one of the pillars for the positive result of the GDP (gross domestic product) in recent years in Brazil. In view of this, the linear growth of this sector has generated greater demand for soil correctives, conditioners and fertilizers, which are inputs that directly affect crop productivity. The use of alternative sources to these inputs has been constantly studied, thus mining and agro-industry can contribute to the alternative development of new inputs for use in soils. In this sense, the state of Pará has the largest aluminum production chain, coming from bauxite mining and, in addition, has a broad agro-industrial development through the cultivation of oil palm, coconut, cocoa, açaí, among others. Occasionally, these chains are potential generators of waste, considered environmental liabilities, which, after chemical characterization, may present potential as soil conditioners and reduce environmental liabilities. The incorporation of oil palm residues that are sources of organic matter and nutrients to bauxite residues (RB), with alkaline properties, high content of organic matter and nutrients, can constitute a product with soil conditioning characteristics, that is, does not compromise the environment and improves soil quality and increases crop productivity. The first chapter of this work aimed to evaluate the physicochemical properties (total N, organic carbon, water holding capacity, cation exchange capacity, carbon-nitrogen ratio, granulometry, macronutrients, micronutrients and PTEs) as well as the ecological risk potential (PERI) of conditioners generated by BR increment under different organic residues of oil palm. For this, we defined a factorial with three doses of BR (25, 50 and 75%) and incorporated in two types of organic wastes from palm oil production (1- fiber, bush and dregs in ideal proportions for composting; 2- mature compost of organic waste from oil palm) in 60 L containers as experimental units and we evaluated after 90 days. The second chapter aimed to evaluate the leaching of chemical elements, estimation of soil and groundwater contamination, soil physicochemical characteristics and agronomic efficiency of Brachiaria grown under soil with application of formulation containing BR and oil palm residues. In this case, we selected the formulations considering the MAPA parameters for soil conditioners, on them we simulated precipitation for 60 days. The columns were composed of PVC pipes filled with 5 kg of medium-textured soil with bottles adapted with hoses to facilitate drainage and collection of leachates. After 60 days, the hoses and bottles were removed and the columns were used as pots for growing Brachiaria. The results indicated that the use of 25% BR associated with oil palm residues constituted a formulation that meets the requirements for soil conditioning. The higher the concentration of organic residues in the formulation the higher the values of cation exchange capacity, water retention capacity, organic carbon, total N, macro and micronutrients, as well as lower sodicity and content of potentially toxic elements (PTEs). The PERI was considered low even with the use of 50% RB. After application of the formulations in the soil the leaching of nine chemical elements was detected, without the presence of EPTs. The treatments neutralized Al3+ in the highest doses of residues and RB and also increased V (55.6%) in relation to native forest soil (10.8%), as occurred with limestone (83%). They also raised soil pH (5.5) in relation to native forest soil (4.7). The production of Brachiaria increased with the use of waste and compared to the native forest soil. Therefore, formulation containing BR and oil palm residues can be classified as soil conditioner without impact on soil and groundwater contamination, besides increasing soil physicochemical parameters and grass production.

BANKING MEMBERS:
Interno - 6388356 - ANTONIO RODRIGUES FERNANDES
Externo à Instituição - ENIO TARSO DE SOUZA COSTA
Externo à Instituição - ANTONIO CLEMENTINO DOS SANTOS - UFT
Externo à Instituição - LEÔNIDAS CARRIJO AZEVEDO MELO - UFLA
Externo à Instituição - SILVIO JUNIO RAMOS - ITV