Banca de DEFESA: PAULA RAÍZA ALVES CAVALCANTE

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : PAULA RAÍZA ALVES CAVALCANTE
DATE: 30/01/2024
TIME: 14:00
LOCAL: meet.google.com/efw-wnxu-ohm
TITLE:

Evaluation of the ecotoxicity of wastes generated in the laundry of the textile polo of Agreste de Pernambuco using the zebrafish (danio rerio)

KEY WORDS:

Textile industry; effluent; sludge; toxicity; aquatic animals.

PAGES: 76
BIG AREA: Engenharias
AREA: Engenharia Sanitária
SUMMARY:

Laundries are part of the textile process and generate significant amounts of effluents (liquid waste) that must undergo treatment before disposal into water bodies. The physical-chemical treatment generates textile sludge, classified as non-hazardous solid waste. The disposal of treated effluent into water bodies is subject to physical-chemical analyses and ecotoxicity tests to determine the compound's harmfulness in the environment. In this sense, the present study aims to analyze the ecotoxicity of residues generated in the Effluent Treatment Station (ETE) of a laundry facility in the Textile Hub of the Agreste region of Pernambuco, located in the city of Caruaru. Mapping scientific publications on the topic allowed for the classification of the zebrafish as a promising model for ecotoxicological analyses of textile effluents, particularly in embryonic and larval analyses, due to their low cost, short period requirement, and adherence to an internationally imposed standard (OECD 236). Thus, the impact of effluents and textile sludge on the embryonic and larval stages of zebrafish was evaluated. For the sludge, solubilization was carried out to obtain the eluate. The effluents and sludge were characterized through physicochemical analyses, including pH, color, turbidity, alkalinity, chloride, COD, total hardness, solids, and metals. For ecotoxicological analyses, embryonic development was initially assessed at 8 hours post-fertilization (hpf) through epiboly. This analysis allowed for the determination of ideal dilutions for each effluent and sludge, considering low coagulation (mortality) and developmental delay. Based on these principles, the dilutions established for ecotoxicity tests until 144 hpf were: ET 6.3%, ET 12.5%, EB 6.3%, ELU 6.3%. Despite all tests conducted, ELU 6.3% exhibited higher toxicity, causing developmental retardation and high mortality in all studied periods, indicating the high toxicity of the sludge. Affected animals exposed to EB 6.3%, ET 12.5%, and ET 6.3% displayed spinal deformities, tail deformities, yolk sac edema, and pericardial edema. There were alterations in heart rate among animals exposed to ET 12% and EB 6.3%. All effluents affected touch sensitivity and thigmotaxis, indicating neurotoxicity. Thus, it is observed that although the treatment of raw effluent proved efficient in reducing some parameters and the NBR 10004/2004 classifies sludge as non-hazardous class II waste, when subjected to more complex ecotoxicological analyses such as the study of animal development and behavior, these residues are found to be toxic even in diluted samples. Some parameters evaluated in this study are not mentioned in regulations but may affect aquatic life. Among these, COD presented high values in all samples evaluated, particularly in the eluate of the sludge, suggesting this parameter as a possible toxic agent. Likewise, Al was the second most abundant metal in all samples evaluated; studies demonstrate that Al can cause toxic effects on the nervous, reproductive, and cardiovasculares systems. Aligning with the neurotoxic responses and cardiovascular changes found in this study, indicating this metal as a possible toxic agent. These ecotoxicological responses indicate that textile effluent and sludge contain compounds that induce ecotoxicity, particularly causing developmental delays, teratogenic damage, cardiovascular, and neurological effects.

COMMITTEE MEMBERS:
Interno - ALEX SOUZA MORAES
Externo à Instituição - ANDRE SOBRAL
Presidente - ROSANGELA GOMES TAVARES
Externa à Instituição - THAMIRIS PINHEIRO SANTOS