Banca de DEFESA: MARIA DENISE BARBOSA GOMES

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : MARIA DENISE BARBOSA GOMES
DATE: 02/04/2025
TIME: 08:30
LOCAL: híbrido (link:meet.google.com/hse-qxrm-nas e sala de aula do LARHISA)
TITLE:

Phosphorus sorption by oxidic soil: Strategies for mitigating eutrophic waters in the Brazilian semiarid region

KEY WORDS:

pH; Humic Substances; Geoengineering; Iron and Aluminum Oxides; Dystroferric Red Nitosol.

PAGES: 56
BIG AREA: Engenharias
AREA: Engenharia Sanitária
SUBÁREA: Saneamento Ambiental
SPECIALTY: Controle da Poluição
SUMMARY:

Eutrophication compromises the water quality of lakes and reservoirs, impacting aquatic biota and ecosystem services. Mitigation involves everything from reducing external sources to blocking internal fertilization. Geoengineering is a technique that can be used to mitigate eutrophic waters by using materials with phosphate adsorption affinity. Natural adsorbents, such as soils, bauxites, and zeolites, emerge as viable alternatives to commercial and more sustainable products. Among them, oxidic soils, rich in Fe and Al oxides, stand out for their high degree of weathering and sorption capacity. This study investigated the potential for P sorption by a tropical oxidic soil to mitigate the eutrophication of aquatic ecosystems in the semiarid region of northeastern Brazil. The experiment was carried out with water from three eutrophic reservoirs (Gargalheiras, Boqueirão de Parelhas and Dourado), using 0.1 g of Dystroferric Red Nitosol, collected at the base and top of a toposequence in the Cabo Basin/PE. After application of the soil (sorbent), the samples were shaken at 200 rpm for 24 hours. The concentrations of phosphate and humic substances, as well as the pH, were evaluated. The tested soils showed P sorption potential, especially at initial concentrations up to 2.5 mg L-1, with P removals reaching above 90% in Gargalheiras and Boqueirão at the initial concentration. The maximum capacity was 3.38 Base and 4.13 mg g⁻¹ Top (Gargalheiras), 2.08 Base and 2.34 mg g⁻¹ Top (Boqueirão) and 1.74 Base and 1.24 mg g⁻¹ Top (Dourado). The sorptive behavior can be attributed to Fe and Al oxides and soil characteristics, such as low pH and organic matter content and high clay fraction. In addition, water properties can also influence sorption, even favoring precipitation. Humic substances reduced after the experiment; however, pH exerted a greater influence on sorption compared to them. Sorbents appear to be a promising strategy for mitigating eutrophic waters, especially in the semiarid region, since both were able to remove P under conditions close to those found in reservoirs.

COMMITTEE MEMBERS:
Presidente - 1764855 - VANESSA BECKER
Interna - 1662859 - KARINA PATRICIA VIEIRA DA CUNHA
Externa à Instituição - FERNANDA MONICELLI CÂMARA BRITO
Externa à Instituição - NATÁLIA PESSOA NOYMA