Banca de DEFESA: IRANILTON FERREIRA DE SOUSA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : IRANILTON FERREIRA DE SOUSA
DATE: 09/04/2025
TIME: 09:00
LOCAL: Sala de aula do LARHISA
TITLE:

APPLICATION OF CALCIUM HYDROXIDE AS A TECHNIQUE FOR MITIGATION OF EUTROPHICATION IN RESERVOIRS IN THE BRAZILIAN SEMI-ARID REGION

KEY WORDS:

hydrated lime, phosphorus sorption, precipitation, alkalinity, humic substances, mitigation.

PAGES: 65
BIG AREA: Engenharias
AREA: Engenharia Sanitária
SUBÁREA: Saneamento Ambiental
SPECIALTY: Qualidade do Ar, das Águas e do Solo
SUMMARY:

Eutrophication is a process of increased primary production caused by increased input of limiting nutrients and represents a serious threat to aquatic ecosystems. This study investigated the potential of hydrated lime used in construction as a phosphorus sorbent using water from four reservoirs in the Brazilian semiarid region. Through microscale experiments in the laboratory, the sorption capacity of hydrated lime in natural water samples was evaluated. The results demonstrated that hydrated lime presented a high capacity for phosphorus removal in natural waters through P sorption and calcium phosphate precipitation, with maximum sorption capacity (qmax) of 176.1 mg.P.g-1 (Dourado), 160.6 mg.P.g-1 (Gargalheiras), 130.3 mg.P.g-1 (Boqueirão) and 111.5 mg.P.g-1 (Armando Ribeiro Gonçalves). Furthermore, hydrated lime was shown to be effective in removing humic substances, contributing to improving water quality. Linear regression analyses showed that increased hardness and humic substances help to increase the qmax of the sorbent material, while the presence of sulfate ions reduces the qmax. Furthermore, the application of lime increased the pH of the medium, a phenomenon that helps in the main sorption mechanism of the material and cancels out the inhibitory effects of calcium phosphate precipitation caused by humic substances. However, this fact requires attention when applying this compound to natural waters. It is concluded that hydrated lime used in civil construction presents itself as a promising and low-cost alternative for controlling eutrophication in reservoirs.

COMMITTEE MEMBERS:
Presidente - 1362202 - JOSE LUIZ DE ATTAYDE
Interna - ***.716.174-** - FABIANA OLIVEIRA DE ARAUJO - UFRN
Externa à Instituição - FERNANDA MONICELLI CÂMARA BRITO - UFRN
Externo à Instituição - JOSÉ NEUCIANO PINHEIRO DE OLIVEIRA - IFCE