Banca de DEFESA: SHARA SONALLY OLIVEIRA DE SOUSA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : SHARA SONALLY OLIVEIRA DE SOUSA
DATE: 12/12/2022
TIME: 14:30
LOCAL: https://meet.google.com/rcb-rzfv-jgy
TITLE:

ECOTOXICOLOGICAL EVALUATION OF THE SLUDGE FROM THE WATER TREATMENT STATION

KEY WORDS:

Solid waste; aluminum, toxicity; bioindicators.

PAGES: 95
BIG AREA: Engenharias
AREA: Engenharia Sanitária
SUMMARY:

The disposal of sludge with a high concentration of aluminum in the environment has as a
consequence the contamination of the environment and the biota present there. An important
environmental issue that is currently being researched is the disposal of WTP waste. In the
scope of international policies, there is the Global Agenda 21; the MDGs, which covered
specific actions with a deadline of 2015; a new agenda for sustainable development, the SDGs,
has been established. Considering the national panorama, there is the environmental issue
mentioned in the Federal Constitution; Law No. 6938, which establishes the National
Environmental Policy This project aims to evaluate the effect of aluminum in the terrestrial
ecosystem through the test of bioindicators of germination using different plant species such as
seeds of tomato, lettuce, chives, cabbage, cucumber and arugula and the Leak test with
earthworms E. andrea and in the aquatic ecosystem through organisms such as microcrustacean
Daphnia similis. The seeds were exposed to different concentrations of the aluminum present in
the sludge and were evaluated for germination and growth inhibition parameters. To evaluate
the toxicity of aluminum-contaminated soils, the escape behavior of earthworms was analyzed.
The principle of the method consists of exposing the organisms to crude samples and to culture
water for control purposes. The test with Daphnia similis was based on the NBR 12713
standards. All seeds when exposed to aluminum sulfate showed total inhibition of germination.
The highest LC50 was 77.82% for lettuce seeds. The seed with the lowest LC50 was chive, with
2.95%. The concentrations 50%, 75% and 100% showed avoidance rates of 80% each,
indicating limited habitat function. It was observed that the (EC-50) of species I Dapnhia is
80.45%, in a confidence interval of 79.95 to 80.94%. As for the mortality of the species to
elutriate exposure, no 100% mortality of the test organisms was observed at any of the
concentrations used in the definitive test. Therefore, since it is still a terrestrial ecosystem, the
WTP sludge presented itself as a toxic effluent to the living organisms present in the soil. The
species Dapnhia similis, used as a reference for aquatic ecosystems, showed toxicity at high
concentrations of aluminum, causing adverse effects. The risk would be in the disposal of
sludge to aquatic fauna in concentrations above 80%. This study showed that the bioindicators
used are suitable for ecotoxicological tests on water treatment plant sludge, since all presented
the sludge as toxic to the aquatic and terrestrial environment. One of the species most often used
as a reference in the aquatic environment is the puffer fish (Danio rerio). Thus, it is suggested
the use of this species to evaluate the toxicity of the WTP sludge in the aquatic environment.

COMMITTEE MEMBERS:
Externa à Instituição - ELISANGELA MARIA DA SILVA
Presidente - ROSANGELA GOMES TAVARES
Interno - VALMIR CRISTIANO MARQUES DE ARRUDA