The indiscriminate use of atrazine herbicide in Brazil and worldwide has several adverse effects on human health and ecosystems, and can be found in soil, ground and surface water, in the air and also in living beings. The biodegradation of this compound can occur through different redox conditions, with the participation of aerobic and anaerobic microbial consortia, generating different degradation metabolites intermediates. However, due to its leaching potential, it is more commonly found in deep soil layers under anaerobic conditions, which highlights the importance of studies in these conditions. This research was carried out with the enrichment of denitrifying microorganisms, sulfate reducing bacteria and methanogenic arches, in anaerobic reactors under different redox conditions (denitrifying, sulfetogenic and methanogenic). Our experimental procedure consisted of two distinct tests, the first being called pure anaerobic reactors (PAR) and the second called composite anaerobic reactors (CAR). The two assays differ in the inoculum used and the carbon sources available in the reactors. We made 6 reactors for each different redox condition, 3 biotic, 2 abiotic, and 1 blank (control). We observed in this study that the removal of atrazine depends on biotic and abiotic factors, which may occur in both ways, and that physicochemical factors such as adsorption and chemical hydrolysis may have significant effects on this process. The results of the tests indicate that there was no variation in atrazine removal between different redox media, 87% (± 7%) for the denitrifying condition, 88% (± 7%) for the sulfetogenic and 92% (± 7%). for methanogenesis, in biotic reactors with atrazine and soil organic content as the only carbon sources for bacteria in the reactors. However, the variation in the results found in RCA supplemented with complementary sources of acetate carbon for denitrifying reactors, lactate for sulfetogens and acetate and formate for methanogens, and reactors without this supplementation (RPA), indicates that high atrazine removal (100%) within 70 days of analysis for supplemented reactors should be done in shorter time periods.

Este artigo discute os principais tópicos ambientais relevantes ao contexto da pandemia pelo novo coronavírus. Por meio de pesquisas bibliográficas de trabalhos recentes e interdisciplinares, foi possível realizar uma abordagem sobre a relevância do saneamento básico no Brasil, assim como as relações entre a pandemia, poluição ambiental e biodiversidade, de forma que, perspectivas futuras puderam ser esboçadas a partir do conhecimento, recursos e conteúdo atual sobre sustentabilidade e qualidade de vida. O artigo também frisa a importância da propagação do conhecimento científico e da realização de projetos de Educação Ambiental visando o desenvolvimento do Brasil e bem-estar da população.

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O uso indiscriminado do herbicida atrazina no Brasil e no mundo apresenta diversos efeitos adversos a saúde humana e aos ecossistemas, podendo ser encontrado no solo, nas águas subterrâneas, no ar e também nos seres vivos, o que justifica pesquisas voltadas à biodegradação, impactos e características deste composto. O presente trabalho, por meio de uma revisão da literatura, mostra que a biodegradação da atrazina pode ocorrer através de diferentes condições de oxirredução, com a participação de consórcios microbianos aeróbios e anaeróbios, gerando diferentes intermediários metabólitos, como a hidroxiatrazina, N-isopropylammilide, ácido cianúrico, biureto, alofanato e uréia. Além disso, esta revisão mostra microrganismos que já foram detectados com o potencial de degradação deste composto utilizando a atrazina como fonte de carbono e/ou nitrogênio, e os seus intermediários metabólicos formados durante os processos aeróbios e anaeróbios de degradação, assim como os principais genes responsáveis pela síntese das enzimas envolvidas na degradação deste composto.

This study analyzes the correlation between the spread of COVID-19 and meteorological variables (air temperature, relative humidity, wind speed, and precipitation) in urban-rural cities located in southeastern Brazil. Spearman's correlation coefficients were used for the statistical analysis. Results show that air temperature and wind speed were positively correlated with COVID-19 cases, while air relative humidity showed negative correlation. As seen in several recent studies, climate factors and the spread of COVID-19 seem to be related. Our study corroborates this hypothesis for less densely populated and less polluted regions. We hope that our findings help worldwide scientific efforts towards understanding this disease and how it spreads in different regions.