Adsorção de contaminantes emergentes e o ambiente aquático: estrutura fitoplanctônica na presença de sulfametoxazol e diclofenaco
Nenhuma Miniatura disponível
Data
2022-12-15
Autores
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Federal de Goiás
Resumo
Chemical products from anthropogenic activities have been one of the main sources of groundwater contamination. They can enter the aquatic environment through domestic sewage, leaching of pesticides and inadequate disposal of chemical products. One of the processes used to remove these contaminants is adsorption, in which different adsorbent materials can be subjected to chemical treatments to improve efficiency in operation. However, environmental analyses are rarely performed with post adsorption effluents. Thus, this study investigates the adsorption process for the emerging contaminants, the anti-inflammatory drug diclofenac (DCF) and the antibiotic sulfamethoxazole (SMX), as well as to evaluate the effects of these drugs on the aquatic environment evaluating the phytoplankton community structure. So, the coconut shell of dendê (Elaies guineenses Jacq) activated carbon was submitted to different chemical treatments and the same were tested in batchs in the removal of DCF and SMX. Kinetic and equilibrium data were obtained for the two contaminants using the best adsorbent. This data was best fitted to Freundlich pseuso-second order models and the best adsorbent was the one treated with phosphoric acid (CDAF), resulting in 80.63% removal for diclofenac and 91.49% removal for sulfamethoxazole. A microcosm experiment was conducted with 16 sampling units, each one with 500 mL of water sample containing phytoplankton exposed to these drugs at different concentrations (0.1, 0.5, and 1.0 mg.L-1). The experiment lasted 15 days, and samples were collected on days 0, 3, 5, 7, and 14 to evaluate the phytoplankton community, the concentrations of the drugs, and the nutrients in the samples. Using the filtered samples from the adsorption assay, representing the effluent from the adsorption process diluted to reach a concentration of 1.0 mg.L-1, plus the acclimated reservoir water containing microalgae, we performe a similar experiment as above, also lasting 15 days. It was identified 6 groups of microalgae, cyanobacteria, diatoms, green algae, myxotrophic flagellates, desmids and xanthophyceans, among them, diatoms and green algae were the most diverse and abundant groups for both experiments. In the first experiment, without containing the effluent, there were significant differences with the use of different concentrations in the samples with DCF in the cyanobacteria groups and significant differences for the desmids group containing SMX. In the post-adsorption effluent experiment, only the desmids group with DCF was significant for the use of the different adsorbents, but by ANOVA the total phytoplankton abundance was significant for the different adsorbents, while in the first experiment the time of duration/exposure to the drugs was significant. In conclusion, this study identified differences in the composition of phytoplankton groups for the two contaminants in the two experiments and in a short period there was a significant response to the interaction between microorganisms and exposure time, and between the different adsorbents used, showing a tendency to decrease the concentration of the drugs in the presence of these microorganisms. Then, the more resistant groups of algae develop more easily, the more sensitive ones decrease or stop developing.
Descrição
Citação
DUARTE, J. A. P. Adsorção de contaminantes emergentes e o ambiente aquático: estrutura fitoplanctônica na presença de sulfametoxazol e diclofenaco. 2023. 85 f. Dissertação (Mestrado em Engenharia Química) - Universidade Federal de Goiás, Goiânia, 2022.