Luiz Antonio Daniel

O Guia Brincadeiras e Interações com água na Educação Infantil tem como objetivo sugerir Práticas Educativas, nas Ciências Ambientais, respeitando os princípios éticos, políticos e estéticos previstos nas Diretrizes Curriculares Nacionais de Educação Infantil (2009) e na Base Nacional Comum Curricular (2018), com a experiência da água por meio de brincadeiras e interações, abordando o tema de maneira contextualizada e significativa, trazendo questões ainda pouco abordadas pelos professores de Educação Infantil, conforme dados levantados na pesquisa de origem. O material foi planejado para que os professores, a partir dele, propiciem às crianças a descoberta, a investigação e a ampliação do conhecimento sobre a água, seus estados, características e transformações. O mesmo traz informações sobre os conteúdos abordados e 5 experiências com a água que poderão ser feitas com as crianças com faixas etárias entre 4 e 5 anos, abarcando suas interfaces por meio de brincadeiras e interações. Este guia oferece experiências em busca de uma mudança efetiva, capaz de promover reflexão e sensibilização através de sua mediação com aprendizagens significativas, sobretudo em um momento em que a preservação do meio ambiente encontra-se em risco.

Eutrophication in water reservoirs releases algal organic matter (AOM), a key precursor to the formation of disinfection by-products (DBPs) during the disinfection process. Typical drinking water treatment is not efficient for AOM removal, and advanced treatments are necessary for the removal of residual AOM before chlorination. UV-based technology with PS and TiO₂ is widely used as a pre-oxidation step in water treatment; however, no publications have focused on them for AOM degradation. In this context, this work investigated the effect of oxidant concentration (0.1 to 0.5 g∙L⁻¹) and pH (6 to 10) on AOM degradation with TiO₂/UV and persulfate (PS)/UV using response surface methodology. In general, PS/UV was more effective in removing protein, while TiO₂/UV was more effective in carbohydrate degradation. TiO₂/UV removals varied from 27 to 57% for protein and from 48 to 86% for carbohydrates. The optimal condition (57% for protein and 86% for carbohydrates) was obtained using 0.5 g∙L⁻¹ TiO₂ at pH 10. PS/UV removals varied from 33 to 81% for protein and from 24 to 53% for carbohydrates. The optimal condition (81% for protein and 53% for carbohydrates) was obtained using 0.5 g∙L⁻¹ PS concentration at pH 8. Degradation kinetics showed a good fit to the pseudo-first-order model (R² > 95%) for both processes. The DBP formation reductions observed with TiO₂/UV—trihalomethane (THM) (85 to 86%) and chloral hydrate (CH) (94 to 96%)—were similar to the efficiencies observed for PS/UV—THM (87 to 89%) and CH (83 to 88%). These results show the efficiency of UV-based technology for AOM degradation and the control of DBP formation.

Algal organic matter (AOM) is a major precursor of disinfection by-products (DBPs) during disinfection. The goal of this study was to critically review available literature about DBP formation from AOM chlor(am)ination. Fifty-six documents from 2010 to 2022 were selected from Web of Science and Scopus databases for further analysis. Previous AOM characterization can indicate DBP formation, but there are no universal predictive parameters and extensive characterization is beneficial. Disinfection parameters (e.g., disinfectant type, dose and contact time), AOM characteristics (e.g., algal species and growth phase), and water quality (e.g., pH, temperature, concentrations of bromide and iodide) all impact DBP yields. Formation of DBPs from AOM is often dominated by trihalomethanes (THMs) and haloacetic acids (HAAs), which reached maximum yields of THMs 177 and 52 μg mg DOC⁻¹, respectively, during formation potential tests. However, yields of haloacetonitriles (HANs) and haloacetamides (HAcAms) can be notably high on occasion, as indicated by respective maximum yields of 103 and 160 μg mg DOC⁻¹ during chlorination of Synechococcus sp. of algae. AOM treatment methods require careful evaluation, considering that some can increase DBP formation, notably ozone (22–781%) and UV (5–95%). Conventional treatment processes resulted in AOM removal typically <65%, thus additional processes, such as ultrafiltration and/or adsorption, downstream of clarification are likely required to effectively control DBP formation from AOM.

Eutrophication in water reservoirs releases algal organic matter (AOM), which is an important precursor of disinfection by-products (DBPs) formed during water treatment. Chlorella sorokiniana is a microalgae which flourishes under conditions of high light intensity and temperature, thus its prevalence in algal blooms is expected to increase with climate change. However, Chlorella sorokiniana AOM has not been previously investigated as a DBP precursor. In this context, this study evaluated the effect of AOM concentration, humic acid (HA), and pH on DBP formation from chlor(am)ination of AOM Chlorella sorokiniana. DBP yields determined by linear regression for trichloromethane (TCM) and chloral hydrate (CH) were 57.9 and 46.0 µg·mg DOC⁻¹ in chlorination, while the TCM, CH, dichloroacetonitrile (DCAN), 1,1,1-trichloropropanone (1,1,1-TCP), and chloropicrin (CPN) concentrations were 33.6, 29.8, 16.7, 2.1, and 1.2 µg·mg DOC⁻¹ in chloramination. Chloramination reduced the formation of TCM and CH but increased CPN, DCAN, and 1,1,1-TCP yields. AOM Chlorella sorokiniana showed a higher DBP formation than 9 of 11 algae species previously investigated in the literature. At basic pH, the concentration of TCM increased while the concentration of other DBP classes decreased. Bromide was effectively incorporated into the AOM structure and high values of bromine incorporation factor were found for THM (1.81–1.89) and HAN (1.32) at 1.5 mg Br·L⁻¹. Empirical models predicted successfully the formation of THM and HAN (R² > 0.86). The bromide concentration had more impact in the model on the DBP formation than AOM and HA. These results provide the first insights into the DBP formation from AOM chlor(am)ination of Chlorella sorokiniana.

Nutrient availability plays a crucial role in microalgae growth in domestic wastewater. In this study, we investigated the impact of different nitrogen and phosphorus ratios (5:1, 10:1, and 20:1, m∙m⁻¹), and the addition of inorganic carbon on microalgae growth and nutrient uptake from domestic wastewater. Microalgae biomass achieved values ranging from 0.54 to 1.41 g·L⁻¹. The cultivation process had maximum removal efficiencies of 83.7% for soluble chemical oxygen demand (sCOD), 74.0% for total Kjeldahl nitrogen (TKN), and 100.0% for ammonia (NH₃) and orthophosphate (PO₄³⁻). All the NH₃ and PO₄³⁻ concentrations from domestic wastewater without supplementation were completely removed on the fourth day of cultivation. Moreover, no significant differences in microalgae growth, and NH₃ and PO₄³⁻ removals were observed between the conditions with and without nutrient supplementation on the fourth day of cultivation. This study has shown the feasibility of growing microalgae in domestic wastewater without any nutritional supplementation. Further investigations are required to check the long-term performance, energy requirements, and economic viability of this system for wastewater treatment and the production of nutrient-rich biomass for agricultural applications.

A eutrofização de recursos hídricos causada por lançamento de esgoto com compostos nitrogenados tem se tornado uma preocupação cada vez maior na área de saneamento. Desta forma, diversos sistemas de tratamento foram criados e estudados para promover a remoção de matéria orgânica e compostos nitrogenados de efluentes com baixa relação C/N – característico de esgoto sanitário e efluentes de tratamento anaeróbio – por meio de diferentes vias de conversão da amônia em gás nitrogênio. Assim, por meio de buscas em sites de pesquisas acadêmicas com palavras-chave do tema, esta revisão tem por objetivo descrever as principais vias de conversão de amônia em gás nitrogênio em sistemas de tratamento e levantar experiências e aplicações reais de 7 sistemas de tratamento diferentes, sendo eles: Modified Ludzack-Ettinger (MLE), Processo Wurmann (PW), University Cape Town (UCT), Bardenpho (BDP), Alimentação distribuída (AD), Nitrificação Parcial seguida de Anammox (NP-Amx) e Desnitrificação Parcial seguida de Anammox (DP - Amx). A análise dos diferentes estudos e aplicações demonstrou que a remoção de nitrogênio pode ser otimizada ao ajustar parâmetros de projeto e promover condições favoráveis aos microrganismos de interesse. Por fim, certos aspectos devem ser considerados na proposição de novos sistemas para remoção biológica de nitrogênio (RBN), como economia de energia, favorecimento das comunidades bacterianas de interesse, conciliar com a geolocalização dos sistemas e otimizar processos para serem operados de forma simples e eficaz. Palavras-chave: Pós-tratamento. Tratamento terciário. Remoção biológica de nitrogênio. Esgoto sanitário. Aplicações reais.

Algal organic matter (AOM) in water reservoirs is a worldwide concern for drinking water treatment; once it is one of the main precursors for disinfection by-products formation (DBPs). In this context, this study investigated the ecotoxicity of DBPs from chlorination of AOM to Ceriodaphnia silvestrii and Daphnia similis (Crustacea, Cladocera). The bioassays evaluated three scenarios, including the AOM extracted from Chlorella sorokiniana, the quenching condition used in the tests, and the DBPs formed after the chlorination of the two test waters with AOM (with and without bromide presence). The results showed that AOM has no toxic effects for the tested species under typical environmental concentration (5 mg∙L⁻¹). However, since AOM is a potential precursor of DBPs, the toxicity of two test waters (TW-1 and TW-2) after the chlorination process (25 mg Cl₂·L⁻¹, for 7 days, at 20 °C) was tested. The sample with higher toxicity to the tested species was TW-1, in which chloroform and chloral hydrate were quantified (615 and 267 µg∙L⁻¹, respectively). However, TW-2 showed lower concentration of chloroform and chloral hydrate (260 and 157 µg∙L⁻¹, respectively), although bromodichloromethane, dibromochloromethane, and bromoform were also detected (464, 366, and 141 µg∙L⁻¹, respectively). Although free chlorine is highly toxic to the tested species, the quenching conditions also affected the organisms’ survival due to the use of ascorbic acid and the presence of reaction intermediates. Nonetheless, both species were more affected by TW-1 and TW-2 than the quenching condition. These results endorse the importance of removing the AOM before the disinfection process to avoid the formation of DBPs. In addition, ecotoxicological analyses could provide a more comprehensive assessment of water quality, especially considering the challenges of quantifying DBPs and other emerging contaminants. Graphical abstract

Biological reactors with immobilized biomass on free carriers have provided new perspectives for wastewater treatment, once they reduce the system size and increase the treatment capacity. In this study, the performance of three Moving Bed Biofilm Reactors (MBBRs) using different carriers (with and without protected surface area) were evaluated for domestic wastewater treatment in continuous flow. Each MBBR (i.e., R1, R2, and R3) was filled at a ratio of 50% with high-density polyethylene (HDPE) carriers with different characteristics: both R1-K1 and R2-Corrugated tube with protected surface and R3-HDPE flakes without protected surface. Chemical oxygen demand (COD) removal of 80 ± 5.0, 80 ± 3.5, and 78 ± 2.4% was achieved by R1, R2, and R3, respectively. The oxygen uptake by biofilm attached on the carriers was 0.0079 ± 0.0013, 0.0033 ± 0.0015, and 0.0031 ± 0.0026 μg DO·mm−2 for the K1, corrugated tube, and HDPE flakes, respectively. No significant differences were observed between the performance of the three MBBRs in terms of physico-chemical parameters (alkalinity, pH, and dissolved inorganic carbon) and COD removal. Results showed that the carrier type and its characteristics (total area and with/without protected area) did not affect the organic matter removal. Thus, the carrier without a protected surface in MBBR could be a promising low-cost option for domestic wastewater treatment.