Banca de DEFESA: JÉSSICA PAPERA DE OLIVEIRA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : JÉSSICA PAPERA DE OLIVEIRA
DATA : 29/04/2019
HORA: 14:00
LOCAL: Sala de videoconferência 03 - SINFO/UFRN
TÍTULO:

SEDIMENT PHOSPHORUS RELEASE IN A TROPICAL SHALLOW LAKE UNDER THE PRESENCE OF OXYGEN

PALAVRAS-CHAVES:

Phosphorus release. Fractionation. Sediments. Aerobic. Temperature.

PÁGINAS: 33
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Sanitária
RESUMO:

Phosphorus (P) is a key nutrient in the eutrophication of freshwater. External nutrient sources are considered one of the main causes of eutrophication. However, even if external loading is reduced, P accumulated in the sediment can be cycled back into the water, due to the process of internal loading. Not every form of P in the sediment is likely to be released into the water column, and its release from sediment is influenced by several factors, such as temperature, dissolved oxygen concentration, organisms, pH, and sediment resuspension. P release under anoxic conditions is largely discussed, but, it can still be released in oxygenated environments. Lake Extremoz is a shallow environment with mixed water column that has been suffering increasing eutrophication. The quality of its water is relevant as it is used for human consumption. During the experiment, the temperature varied up to 3.2°C, what led to Lake Extremoz’s releasing sediment P into the water column, regardless of the aerobic conditions. By the end of the experiment, the majority of the P in the water overlying the sediment was organic (P-Org). That is, in the beakers that had filtered lake water over the sediment, 58.00 µg.L^-1 were of P-Org out of 58.25 µg.L^-1 total P. And, in the beakers that had deionised water overlying the sediment, total P concentration was of 32.83 µg.L^-1, of which 30.74 µg.L^-1 were organic. Most of the P flux into the water after the increase in temperature was composed by organic phosphorus. The change of P concentrations in the water following the change in temperature and the relevance of P-Org, imply that the effects of temperature and organisms on the P cycle control internal loading in the presence of oxygen.

MEMBROS DA BANCA:
Interna - 052.716.174-83 - FABIANA OLIVEIRA DE ARAUJO SILVA - UFRN
Externo à Instituição - JOSÉ NEUCIANO PINHEIRO DE OLIVEIRA - IFCE
Externa à Instituição - MARCELA APARECIDA CAMPOS NEVES MIRANDA - INPE
Presidente - 1764855 - VANESSA BECKER