Multi-taxon trends and the application of genotoxic biomarkers in the analysis of effluents from sewage treatment plant.

Sewage is a significant source of many contaminants, and the effectiveness of sewage treatment plants (STPs) is fundamental to ensure that the effluents produced by these plants have a minimal impact on aquatic environments and guarantee their long-term sustainability. The present study is based on a global scientometric survey of the published research on the application of genotoxicity biomarkers for the analysis of the effects of the contaminants found in the effluents and residues produced by STPs. The literature search focused on the Web of Science and Scopus databases. Research trends were investigated based on the year of publication of each study, the country in which it was developed, the type(s) of genotoxic assay applied, the model organism(s), the type of study (experimental or field study), the physicochemical parameters analyzed, and the principal findings of the genotoxic assays. A total of 134 papers, published between 1988 and April 2023, were selected for analysis. The studies were conducted in a total of 33 different countries, but primarily in Brazil, China, Germany. These studies employed 16 biomarkers to assess genotoxicity, of which, the micronucleus test was the most used. The studies reported on a number of genotoxic substances, such as pollutants, including pesticides, microplastics, metals, and drugs. The data produced by these studies provide important insights into the genotoxic effect of the xenobiotic agents found in STP effluents, which are capable of damaging the DNA of a range of different organisms.

Environmental performance of an integrated water supply and wastewater system through life cycle assessment - A Brazilian case study.

The objective of this study was to evaluate the environmental performance of an integrated water supply and wastewater system that employs a system of ponds at the wastewater treatment system. Additionally, this study aimed to understand the contribution of each stage of the system to the analyzed impact categories, and to evaluate alternative scenarios that consider the reduction of water losses in distribution, as well as the operation of an upflow anaerobic sludge blanket (UASB) reactor in the wastewater treatment plant (WWTP). The evaluation was performed through life cycle assessment (LCA) that considered the stages of water withdrawal, treatment, and distribution along with wastewater collection and treatment. The system was modeled in the OpenLCA software using the Ecoinvent 3.7.1 database. Environmental impacts were assessed using the ReCiPe method and cumulative energy demand. The results show that the water withdrawal stage is the potential source of the greatest environmental impacts. There are exceptions in the categories of climate change and photochemical oxidant formation, which are most impacted by the WWTP. Analysis of alternative scenarios revealed that the decrease in water loss rates during distribution contribute to a linear reduction in potential environmental impacts of the analyzed categories. The operation of a UASB reactor in the WWTP leads to a reduction in impacts on the categories of climate change (41.4%) and formation of photochemical oxidants (11.6%), and to increases in impacts on the other categories analyzed. The data presented provide important information for the improvement of public policies aimed at sanitation in developing countries.

Uso do modelo HEC-RAS com base em informações de LiDAR para avaliação de inundações urbanas / Use of the HEC-RAS model based on LiDAR information for urban flood assessment

RESUMO O crescimento desordenado das cidades e o excesso de impermeabilização são problemáticas dos grandes centros urbanos, tendo como consequência principal a ocorrência de inundações e alagamentos. Nesse contexto, a modelagem hidrodinâmica pode ser uma importante ferramenta para a determinação de áreas inundáveis, permitindo estimar as cotas de inundação para diferentes cenários de tempos de retorno (TR) e chuvas de projetos, permitindo, assim, representar mais fielmente a realidade e minimizar erros decorrentes de projetos hidráulicos. Trabalhando em conjunto com o Sistema de Informações Geográficas (SIG), em que a geometria do canal é extraída por meio do Modelo Digital do Terreno (MDT) de alta precisão gerado por levantamento com técnica LiDAR (Light Detection and Ranging) e software de modelagem hidrodinâmica (Hydrologic Engineering Center — River Analysis System — HEC-RAS), foi possível avaliar diferentes cenários de inundações no trecho canalizado em concreto, no córrego Botafogo, em Goiânia, Goiás. Com os resultados da modelagem hidrodinâmica foi possível avaliar o comportamento da propagação das vazões geradas, constatando-se que para precipitações com TR de 50 anos ou mais, os limites da canalização não suportam os volumes gerados e transportados, provocando inundações em seis trechos críticos. Os dados obtidos pelo HEC-RAS puderam ser validados a partir de registros fotográficos divulgados pela imprensa local e levantamento topográfico dos locais inundados, de modo que a integração entre o SIG e a modelagem hidrodinâmica se mostrou eficiente para o estudo de áreas inundáveis.

ABSTRACT The disordered growth of cities and the excessive waterproofing are problematic of the large urban centers, having as a main consequence the occurrence of floods and overflows. Within this context, hydrodynamic modeling can be an important tool for the determination of floodable areas, allowing the estimation of flood quotas for different scenarios of return periods (TR) and project rainfall, thus allowing to more accurately represent reality and minimize errors arising from hydraulic designs. Working with Geographic Information System (GIS), where the channel geometry is extracted using the high precision Digital Terrain Model (DTM) generated by LiDAR (Light Detection and Ranging) survey and hydrodynamic modeling software (HEC-RAS), it was possible to evaluate different flood scenarios in the channeled concrete section, in the Botafogo Stream in Goiânia, Goiás. With the results of hydrodynamic modeling, it was possible to evaluate the propagation behavior of the generated flows, finding that for precipitation with TR 50 years or older, the plumbing limits do not support the generated and transported volumes, causing flooding in six critical stretches. The data obtained by HEC-RAS could be validated from photographic records released by the press and topographic survey of flooded sites, so that the integration between GIS and hydrodynamic modeling proved to be efficient for the study of floodable areas.

Genotoxic effect of heavy metals on Astyanax lacustris in an urban stream.

Uncontrolled urbanization growth contributes to the pollution of aquatic environments. Heavy metals released by domestic and industrial effluents can negatively affect aquatic organisms. This study aimed to evaluate the effect of environmental pollutants, such as metals, on fish DNA damage, in stretches of an urban stream. Specimens of the Neotropical fish, Astyanax lacustris, were exposed in situ for 96 h along the Antas stream, a Brazilian aquatic system deteriorated by anthropogenic factors. Water and sediment samples were collected simultaneously for physicochemical and heavy metal analyses. The comet assay was performed as a biomarker of genotoxicity. Fish located downstream had a higher frequency of DNA damage than in the reference site. We found concentrations of Cr and Ni above acceptable levels in sediment samples. Generally, Ba, Mn, Mg, Zn, Cr, and Ni were the elements most associated with genotoxic damage. Water and sediment of the Antas stream showed genotoxic potential in A. lacustris according to the urbanization gradient, demonstrating the importance to prevent the release of environmental pollutants, especially heavy metals in urban areas.

Calibração do Storm Water Management Model (SWMM) utilizando algoritmos evolucionários multiobjetivo / Storm Water Management Model calibration using multiobjective evolutionary algorithms

RESUMO O estudo teve por objetivo a realização da calibração do modelo hidrológico Storm Water Management Model (SWMM) para a Bacia Hidrográfica do Arroio Cancela, localizada em Santa Maria, Rio Grande do Sul, utilizando o algoritmo evolucionário multiobjetivo R-NSGA. Para tanto, foram realizadas modificações na estrutura do SWMM, de modo que permitisse seu acoplamento como Evolucionary Reference Point Based Non-Dominated Sorting Genetic Algorithm (R-NSGA) em ambiente de programação MATLAB. As funções objetivo utilizadas foram o Coeficiente de Eficiência de Nash-Sutcliffe (COE), o Erro da Vazão de Pico (EQP) e o Erro do Volume Escoado (EVOL) aplicadas simultaneamente na calibração do modelo. Foi proposto um método para determinação da maior compatibilidade de modo a elencar as melhores soluções. Os resultados dos parâmetros calibrados do SWMM foram próximos aos valores físicos da bacia, com exceção dos valores relativos à equação de Horton. As soluções de maior compatibilidade apresentam um melhor comportamento para os eventos de validação, evidenciando a importância da otimização multiobjetivo.

ABSTRACT This paper focused on the calibration of Storm Water Management Model (SWMM) for the Cancela River Basin, located in Santa Maria, Rio Grande do Sul, Brazil, using the multi-objective Evolucionary Reference Point Based Non-Dominated Sorting Genetic Algorithm R-NSGA. Modifications were made in SWMM structure to allow its linking with R-NSGA in MATLAB. The objective functions proposed were the efficiency coefficient of Nash-Sutcliffe (eNS), the Peak Flow Error (EQ) and Runoff Volume error (EVOL), which were applied simultaneously to the model calibration. A method for determining the maximum compatibility to rank the best solutions is proposed. The parameters estimated by SWMM calibration were close to physical values of the basin, except those relating to the Horton equation in the most compatible solutions have a better behavior for the validation event, highlighting the importance of multi-objective optimization.

Modelos de análise hidráulica de redes de distribuição de água considerando demanda dirigida pela pressão e vazamentos / Water distribution networks analysis considering leakage and pressure driven demand modeling

As ferramentas para análise hidráulica são componentes importantes na avaliação do funcionamento das redes de distribuição de água para abastecimento. Existem diversos métodos que podem ser utilizados para essa análise, no entanto, os modelos que procuram resolver o sistema de equações correspondente através do método Newton-Raphson ou por meio de linearizações sucessivas são os mais eficientes. Quatro formulações baseadas nestes esquemas são avaliadas neste trabalho. O objetivo deste trabalho é fazer uma comparação dos métodos Newton-Raphson, Teoria Linear, Híbrido e Gradiente para a análise de redes de distribuição de água em regime permanente, considerando a demanda dirigida pela pressão e os Vazamentos. Para tanto, foi utilizado um layout de rede frequentemente empregado na literatura dotado de válvulas. O método do Gradiente foi o que convergiu em um número menor de iterações para redes mais simples, o Método Híbrido foi o que mais se adaptou para sistemas mais complexos.

The hydraulic analysis tools are important in the performance evaluation of water distribution networks. Various methods are available for such analysis. However, the hydraulic models that solve the system of equations describing the flow problem through Newton-Raphson or through its successive linearizations are the most efficient. It is the purpose of this paper to compare Newton-Raphson, Linear Theory, Hybrid and Gradient methods for steady-state hydraulic network analysis, considering leakage and pressure driven demand modeling. The network layout with hydraulic components frequently used in the literature was employed for this analysis. The Gradient method was found to produce best results in terms of number of iterations for the more simple networks, whereas the Hybrid method was better for more complex networks.