Banca de DEFESA: LOHANA SILVA TORQUATO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : LOHANA SILVA TORQUATO
DATE: 27/02/2025
TIME: 14:00
LOCAL: Sala de Salinidade do Solo
TITLE:

Heavy metals in mangrove soils of Bahia and Pernambuco states

KEY WORDS:

Contamination. Estuary. Trace elements.

PAGES: 58
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Ciência do Solo
SPECIALTY: Química do Solo
SUMMARY:

The growing contamination of the mangrove ecosystem has highlighted the need to understand the environmental impacts resulting from human action. The states of Bahia and Pernambuco hold 25% and 7.27%, respectively, of the total mangrove area in northeastern Brazil. These states have areas of intense industrial and urban activity surrounding the mangroves, which are part of important water supply systems for metropolitan regions. However, assessments of risks associated with anthropogenic interference in these environments are still scarce. Therefore, this study aims to expand the research on heavy metal contamination in the mangroves of Bahia and Pernambuco. To characterize the area, soil samples were collected from mangrove areas with a history of contamination in the Botafogo River and Santa Cruz Channel in Pernambuco, and Subaé, São Paulo, and Paraguaçu Rivers in Bahia. In each estuary, three collection points were selected: lower, middle, and upper estuary, totaling 15 georeferenced areas. In each area, three composite samples were collected at 10 m from the shore and three at 30 m from the shore, totaling 6 plots, at depths of 0-5 and 5-10 cm. The samples were prepared and analyzed to determine the levels of environmentally available heavy metals such as cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), nickel (Ni), and zinc (Zn) using the USEPA 3051a method, with microwave digestion and ICP-OES dosing. Soil granulometry was also performed using the micropipette method after pretreatment to remove salts and organic matter. In Bahia, Cd was identified as the main contaminant of the Subaé River, reaching 2.83 mg/kg-1, exceeding VRQ, VP, TEL, and ERL at all collection points, demonstrating the need for investigation and monitoring of the area. The São Paulo and Paraguaçu Rivers showed safe toxicity levels determined by CETESB and international environmental agencies. However, there is a need for monitoring as these are study areas related to contamination by anthropogenic sources such as domestic and industrial sewage and are part of the Todos os Santos Bay, which plays a crucial role in the state's water supply. The average levels of metals obtained in the Botafogo River at the highest concentration point were: Cd (0.10 mg/kg-1), Cr (35.3 mg/kg-1), Cu (10.80 mg/kg-1), Ni (8.88 mg/kg-1), Pb (18.80 mg/kg-1) and Zn (31.50 mg/kg-1), however, they do not indicate a probable toxic effect from any of the metals, remaining within VRQ and TEL limits and below the other reference values. The Santa Cruz Channel showed lower levels than those found in the Botafogo River, indicating low contamination at the collection points.

COMMITTEE MEMBERS:
Presidente - CAROLINE MIRANDA BIONDI
Interno - YGOR JACQUES AGRA BEZERRA DA SILVA
Externo ao Programa - ***.572.444-** - GABRIEL HENRIQUE MÁXIMO CLARINDO SILVA - UFRPE
Externa ao Programa - ***.044.794-** - PAULA RENATA MUNIZ ARAUJO - UFPE