Banca de DEFESA: MARIANA DE AGUILAR SANTOS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : MARIANA DE AGUILAR SANTOS
DATE: 25/08/2022
TIME: 14:00
LOCAL: Auditório do Campus VI - Belo Horizonte
TITLE:

EVALUATION OF CHEMICAL AND BIOLOGICAL ATTRIBUTES OF CONSTRUCTED NICHES USING IRON ORE TAILING: an alternative for the revitalization of degraded areas.

KEY WORDS:

Constructed niche, iron ore tailings, bentonite clay and fungi biocomposite.

PAGES: 70
BIG AREA: Outra
AREA: Multidisciplinar
SUMMARY:

The iron ore extraction industry is one of the important sectors for the Brazilian economy, especially in the Quadrilátero Ferrífero region, Minas Gerais. This activity generates a significant environmental impact on the Campo Rupestre ecosystem and the disposal of the generated tailings is a recurring socio-environmental problem, especially after the failure of two tailings dams in the state. The use of Constructed Niche (CN) is a recently presented technique, which has as its constituent iron ore tailings, topsoil, and binder. The application of the NC technique aims to mimic pre-existing ecological niches in areas degraded by mining activities, by bringing biotic components from the place of interest. This study aimed to characterize the topsoil of a non-degraded area of CR in terms of chemical and mineralogical composition and fertility; to evaluate the effects of new CN constituents (such as bentonite clay and fungal mycelium biocomposite) on its mechanical property and on its biological attributes, such as: microbial biomass carbon (MBC), basal respiration (BR) and metabolic quotient (qCO₂ ) and observe the presence of photobiont organisms during the incubation period from 7 and 180 days. The CNs were made by adding different proportions of topsoil from CR of the Serra da Piedade, iron ore tailings (30%), cement (5%), clay (10%) and biocomposite (10%). XRD and XRF analyzes of topsoil identified minerals such as hematite, quartz and goethite and high proportions of Fe oxide and silicon dioxide. Fertility analyzes showed low concentration of nutrients, including Ca, K, P, and CEC (cation exchange capacity), as well as low content of organic matter, C, N and acidic pH. These observed features are typical of ferruginous CR topsoil. The new binders used in the manufacture of CNs did not provide strength to the material, making it necessary to test new proportions in future studies. Only the cement conferred resistance to the CN, as it is a good binder, promoting the cohesion of the constituent particles of the module (topsoil + tailings). The MBC between the controls and the treatments showed no significant difference when compared between the two incubation times, except for the NC containing the biocomposite. The BR results were low for the controls and topsoil + tailings, but in the treatments containing clay and biocomposite the results were significant. The growth of photobionts such as bryophyte gametophytes, pteridophyte prothallus, angiosperm seedlings and algae were observed in topsoil and topsoil+tailings. For CNs containing cement and clay there was the appearance of fungi during the incubation period and, in the time of 180 days, in addition to fungi, the development of angiosperm was observed on the surface of the CN containing the biocomposite. The analyzes of the present study indicate that the CN made with biocomposite has greater potential to act as life development stimulators.

BANKING MEMBERS:
Presidente - ANDREA RODRIGUES MARQUES
Interna - PATRICIA SUELI DE REZENDE
Interna - FERNANDA BADOTTI
Interna - ANGELA DE MELLO FERREIRA
Externa ao Programa - VALERIA CRISTINA PALMEIRA ZAGO
Externa ao Programa - FABIANA DA CONCEICAO PEREIRA TIAGO