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| Author(s): |
Gabriela Cristina Fonseca Almeida
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Limeira, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Faculdade de Tecnologia |
| Defense date: | 2023-08-30 |
| Examining board members: |
Gisela de Aragão Umbuzeiro;
Amanda dos Santos;
Clarice Maria Rispoli Botta
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| Advisor: | Gisela de Aragão Umbuzeiro |
| Abstract | |
The discharge of domestic, municipal and industrial effluents is often the main source of aquatic toxicity observed in surface waters. According to Brazilian legislation CONAMA Resolution nº 430/11, effluents must not have the potential to cause an impact on the receiving body and, to evaluate this impact, toxicity tests are necessary. The assessment of the potential impact of effluents must be carried out based on the average of effluent releases and in reference to the respective receiving bodies, in accordance with CONAMA Resolutions 430/11 and SMA 03/2000. In this work, the ecotoxicity of final effluents from different Wastewater Treatment Plants (WWTP) in the State of São Paulo, Brazil (named A, B, C, D) were evaluated. Each WWTP uses a different type of treatment. WWTP A uses UASB reactors followed by activated sludge and decantation; WWTP B uses batch activated sludge followed by chlorination; WWTP C uses UASB reactors followed by an anoxic chamber, submerged aerated biological filter, secondary decanter and chlorination. WWTP D uses biological reactors and ultrafiltration (Membrane Bio Reactor, MBR). Six monthly campaigns were evaluated. All samples were tested for acute toxicity with Daphnia similis. Two samples from each WWTP, which did not show acute toxicity to D. similis, were selected for chronic evaluation with Ceriodaphnia dubia. In addition, two samples from each WWTP were analyzed for acute toxicity with Danio rerio (FET). The results were expressed in EC/LC50, IC10 and in Toxic Units (TU). All ETE B effluents showed acute toxicity for D. similis with EC50 between 60.8% to 25% mortality in the 100% sample. The effluents from WWTPs A and C showed acute toxicity in at least one campaign and chronic toxicity was detected in the two evaluated samples of each WWTP with IC10 from 3 and 45%. D. rerio was less sensitive than D. similis for ETEs A and C, but for a sample from ETE B it was more sensitive. For WWTPs A, B and C, ammonia was the main probable cause of the acute toxicity detected with D. similis. WWTP D did not show any toxic samples for D. similis or C. dubia but, showed signs of acute for D. rerio. WWTP C effluents have the potential to cause an impact on the receiving body. Although WWTP B showed acute toxicity for most samples and signs of toxicity in a one sample for D. similis and two toxic samples for D. rerio, it did not sshow potential to cause impact on the receiving body due to the effluent high dilution in the receiving body. The treatment that uses biological reactors and ultrafiltration was the one that presented better quality effluents in terms of toxicity when compared to the other types of treatment adopted by the three WWTP evaluated. The use of toxicological tests proved to be a good tool to complement chemical analyzes in evaluating the quality of final effluents. In addition, the results can help in the choice of better treatments, contributing to the improvement of the quality of the receiving water bodies (AU) | |
| FAPESP's process: | 21/01204-5 - Sewage ecotoxicity treated as an operational parameter in WWTPs and evaluation of the possible impact on the receiving bodies |
| Grantee: | Gabriela Cristina Fonseca Almeida |
| Support Opportunities: | Scholarships in Brazil - Master |