Banca de DEFESA: MATEUS AUGUSTO DE CARVALHO SANTANA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : MATEUS AUGUSTO DE CARVALHO SANTANA
DATE: 27/02/2025
TIME: 14:00
LOCAL: Google Meet
TITLE:

WATER AND SEDIMENT QUALITY IN URBAN WATERSHEDS IN THE EASTERN AMAZON

KEY WORDS:

Environmental contamination; potentially toxic elements; human health risks; environmental risks.

PAGES: 50
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Ciência do Solo
SPECIALTY: Química do Solo
SUMMARY:

Several cities in the Amazon have been impacted by urbanization and industrialization, increasing the inappropriate discharge of effluents and domestic waste, which compromise water quality and may cause contamination by potentially toxic elements (PTEs) in urban watersheds. The objectives of this study were to characterize the properties, determine the concentrations of PTEs, and assess the risks related to these contaminants in water and sediments from watersheds in Belém, eastern Amazon. Samples were collected and analyzed at 81 points, including 76 in anthropized watersheds (ARM, ENO, ICO, MTF, MUR, PCR, TAM, TUC, UNA, and VAL) and five in a reference area (CHR). Collection was performed using Van Dorn bottles for water and an Ekman-Birge sampler for sediments. The physicochemical properties of the water were measured in situ with a multiparameter probe, determining temperature, pH, dissolved oxygen (DO), total dissolved solids (TDS) and electrical conductivity (EC). The PTEs in the water and sediments were extracted by acid digestion and quantified by microwave-induced plasma atomic emission spectrometry. The results were interpreted based on resolutions 357/2005 and 454/2012 of the National Environmental Council (CONAMA) and statistically analyzed by the Kruskal-Wallis and Dunn tests (p < 0.05). The results indicated that cadmium (Cd) and vanadium (V) presented values above the recommended for CONAMA class II freshwaters, while cobalt (Co) and copper (Cu) exceeded the limits in some basins. Water quality varied between the anthropized basins and the reference area, with differences in DO, pH, EC and TDS, evidencing anthropic impacts. For sediments, Cd concentrations reached level 1 in most basins, indicating possible ecotoxicological risk. The ARM, ICO and TAM basins presented high values of Cu and Zn, while only TAM exceeded level 1 for Pb. No PTE exceeded level 2 according to CONAMA resolution 452/2012. The ecological risk assessment revealed low risk for Ba, Co, Cr, Mn and Zn, while Cd, Pb, V, Ni and Cu presented moderate risk in some basins. The results show contamination in the urban basins of Belém by toxic elements. Public policies should focus on effluent treatment and control of disorderly urbanization. Effective measures can reduce environmental impacts and protect water quality.

COMMITTEE MEMBERS:
Presidente - 6388356 - ANTONIO RODRIGUES FERNANDES
Externo à Instituição - Gerson Moreira Barros - IFPA
Externo à Instituição - MARCIO SOUSA DA SILVA - ITV
Externo à Instituição - SILVIO JUNIO RAMOS - ITV