Banca de DEFESA: KATERÍN MANUELITA ENCINA OLIVA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : KATERÍN MANUELITA ENCINA OLIVA
DATE: 29/09/2023
TIME: 14:00
LOCAL: meet.google.com/ymh-iyrs-cht
TITLE:

Bed sediments for the assessment of contamination by potentially toxic elements in coastal watersheds from Pernambuco

KEY WORDS:

Heavy metals. Environmental risk. Ecological risk potential, Contamination indices 

PAGES: 122
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Ciência do Solo
SPECIALTY: Manejo e Conservação do Solo
SUMMARY:

An integrated study of soil and sediment quality is fundamental to understanding the impacts
of agricultural, urban, and industrial activities on water resources. Sediments are the link
between terrestrial and aquatic ecosystems. Therefore, changes in sediment quality reflect the
impacts of various anthropogenic activities. The objectives of this study were (1) to evaluate
the total levels of potentially toxic elements (PTEs) in bed sediments in the Ipojuca, Jaboatão,
and Beberibe watersheds, as well as the levels of these elements in soil samples from different
areas of the Ipojuca river basin, (2) determine the concentration of PTEs in the different
compartments of the sediment matrix using sequential extraction analysis, (3) evaluate the
influence of particle/sediment size on the retention of PTEs, (4) evaluate the degree of
contamination of the Beberibe and Jaboatão basins using contamination indices, as well as the
potential ecological risk posed by the contaminants. Soil samples were collected from Caatinga
areas, channel banks, and areas where sugar cane is grown in the Ipojuca River basin. Bed
sediment samples were collected from the first 5 cm of the three river basins aforementioned.
In the Riverjuca River basin, PTEs were evaluated in the 2 mm, 63µm, and 32µm fractions.
The PTEs were analyzed using ICP-OES. In the Ipojuca River basin, the average concentrations
of Mn (447 mg kg-1), Pb (49.39 mg kg-1) and Zn (64.85 mg kg-1) were higher upstream,
specifically in the Caatinga area. Downstream, the highest concentrations were of Cr (43.92 mg
kg-1), Fe (43969 mg kg-1), and Ni (17.60 mg kg-1), mainly in the channel bank. In the bed
sediment, Ni, Pb, and Zn concentrations were higher upstream, while Cr, Fe, and Mn were
higher downstream. The highest concentrations of PTEs were found in particles with diameters
< 32µm. Cr and Fe present the lowest ecological risk because they have a higher concentration
in the residual fraction, while Mn and No have a higher concentration in the exchangeable
fraction and therefore present a higher environmental risk. In the Beberibe River basin, the
averages for Mn, Pb, and Zn were higher in the first collection, while the levels of Cr, Cu, Ni,
and organic matter (OM) were higher in the second collection. In the Jaboatão River basin, Cr,
Cu, Mn, Ni, Zn, and OM were higher in the first sampling and only Pb was higher in the second
sampling. Both basins show high contamination by Cu, and considerable contamination by Zn,
while in the Beberibe basin, there was moderate contamination by Pb and in the Jaboatão basin
the same trend was observed for Cr, Mn, Ni, and Pb. The Beberibe basin presents a low to
considerable ecological risk, while the Jaboatão basin presents a low ecological risk. In the
Beberibe River basin, there was a higher environmental risk for Mn and Ni because it has a
considerable percentage of these elements in the exchangeable fraction. The greatest
environmental risk in the Jaboatão River basin is generated by Mn. In the Beberibe River, Mn
comes from natural sources, while the other metals come from anthropogenic sources. In the
Jaboatão river basin, Fe and Ni derive from natural sources and Mn, Zn, Pb, Cr, and Cu derive
from anthropogenic sources.

COMMITTEE MEMBERS:
Presidente - ***.385.794-** - YURI JACQUES AGRA BEZERRA DA SILVA - UFPI
Externa à Instituição - LILY TELLO
Externo à Instituição - JÚLIO CESAR AZEVEDO NOBREGA - UFRB
Externa à Instituição - JANE KELLY SILVA ARAUJO
Externa à Instituição - MARIA EUGENIA ORTIZ ESCOBAR