Resumen en Inglés:

ABSTRACT The coffee industry and landfill leachate treatment produce waste: spent coffee grounds (SCG) and landfill leachate membrane concentrate (LLMC). Current disposal methods, such as open burning, incineration, and landfilling, waste resources and hinder sustainability. Due to their high pollution potential, cost-effective management solutions are urgently needed. This research explores the slow pyrolysis of SCG using potassium hydroxide (KOH) and LLMC as activating agents (1:1 weight ratio). LLMC’s high alkali and alkaline earth metal content may enhance char activation and improve char quality. Using LLMC as an activating agent offers an alternative to value SCG and landfill waste, potentially replacing industrial-scale activators like steam, CO2, and chemical additives. SCG had a low specific surface area (4.5 m2 g-1), contrasting with the notable surface areas observed in both activated chars. In particular, the KOH-activated char exhibited a higher surface area than the LLMC-activated char, measuring 1.960 m2 g-1 compared to 1.138 m2 g-1 - a difference of about 72%. On the other hand, the combustion enthalpy of the LLMC-activated material was estimated at 22.04 MJ kg-1. The combustion enthalpy of LLMC-activated char was about 21.7% and 19.8% higher than that of SCG and KOH-activated chars, which had values of 18.11 and 18.40 MJ kg-1, respectively. This work showed that both activated chars had superior energetic and morphological properties compared to non-activated chars made from SCG biomass. Among the activating agents, KOH led to better performance in terms of char yield and morphological properties. Meanwhile, utilizing LLMC as an activating agent highlights its potential for converting landfill waste into high-value material.

Resumen en Inglés:

ABSTRACT Extreme precipitation events (EPEs) are major drivers of natural disasters, often resulting in economic and social losses, infrastructure damage, and fatalities. In this context, advancing the understanding of their spatial behavior, frequency, and underlying atmospheric mechanisms is essential for improving preparedness and disaster risk reduction. This study examined EPEs across the state of São Paulo, the most populous region in Brazil, using daily rainfall data from 21 pluviometric stations for the period 1970–2022. Extreme events were defined using the 99th percentile (P99) threshold for each station. Results revealed a marked spatial contrast: the highest P99 values occurred in the northern and northwestern regions of the state, whereas the lowest thresholds were observed in the southern sector. On the other side, the frequency of days exceeding P99 showed the opposite pattern, with more EPEs recorded in southern São Paulo than in the north. Based on the days that exceeded P99, the atmospheric systems associated with EPEs were classified for the 1996–2022 period. Cold fronts accounted for 46% of the events, followed by the South Atlantic Convergence Zone (SACZ) at 28% and convective mesoscale systems at 26%. These findings highlight the distinct spatial and synoptic controls on extreme rainfall across São Paulo and underscore the need for region-specific monitoring and early warning strategies.

Resumen en Inglés:

ABSTRACT The present study used toxicity tests to investigate the effects of several toxicants on the growth of aerobic (activated sludge), anaerobic (sludge) (Upflow Anaerobic Sludge Blanket (UASB)), and algal (Chlorella vulgaris cultivation) biomasses. The toxicants analyzed are included in Brazilian water authorities’ regulations for the discharge of non-domestic wastewater (NDW) into sanitary sewage networks. First, the concentration ranges commonly reported as inhibitory for the three types of biomass were surveyed in the literature. Based on this survey and considering the limits established by the NDW discharge regulations in Brazil, three doses were defined for each substance, to be used in aerobic (dissolved oxygen consumption rate), anaerobic (methane production rate), and algal (cell growth rate) toxicity tests. The tests revealed that the biomasses exhibited quite variable minimum inhibitory concentrations (MIC); aerobic biomass appeared to be more tolerant (MIC in greater magnitude) than anaerobic and algal biomass, with the latter being the most sensitive. Aerobic sludge was particularly sensitive (toxicity observed at 1 mg.L-1) to lead, cobalt, total chromium, iron, zinc, and sulfide. In comparison, anaerobic sludge was more sensitive to tin and mercury (0.1 and 0.5 mg.L-1, respectively). Algal biomass was more sensitive to vanadium, cobalt, and sulfide (0.2, 0.5, and 0.5 mg.L-1, respectively). Arsenic, copper, total chromium, iron, phenols, and sulfate had minimum inhibitory doses (for all three biomasses) lower than the values proposed by some Brazilian water authorities, indicating the need for more in-depth studies on these substances to encourage future reviews of the currently established limits.

Resumen en Portugués:

RESUMO O gerenciamento de resíduos de equipamentos elétricos e eletrônicos tem ganhado relevância global, especialmente com o crescente volume de resíduos gerados e a necessidade de práticas sustentáveis. Este estudo propõe e aplica uma metodologia para analisar disparidade entre a legislação brasileira e a literatura no que tange à atribuição de responsabilidades aos stakeholders em cadeias de suprimentos reversas. A pesquisa, que inclui revisão sistemática da literatura e análise de conteúdo dos instrumentos legais brasileiros relacionados a responsabilidades de stakeholders em cadeias de suprimentos reversas de resíduos de equipamentos elétricos e eletrônicos, revela lacunas entre as responsabilidades teóricas e as abordagens legais. A comparação entre a literatura e os instrumentos legais brasileiros destaca a falta de regulamentações sobre práticas como o pagamento antecipado de taxas para gestão de resíduos e o papel de consumidores, varejistas e governos na cadeia de reciclagem. O estudo propõe um framework para designação e compartilhamento de responsabilidades em cadeias de suprimentos reversas que pode servir como base para proposição de políticas públicas e estratégias empresariais mais eficazes, visando a uma economia circular mais robusta. As conclusões reforçam a importância de uma maior integração entre políticas públicas e práticas de cadeias de suprimentos reversas no Brasil, além de sugerir atualizações nos instrumentos legais brasileiros para promover uma maior colaboração entre os diferentes stakeholders, garantindo a eficácia de sistemas de logística reversa e a sustentabilidade no gerenciamento de resíduos de equipamentos elétricos e eletrônicos.

Resumen en Inglés:

ABSTRACT The management of Waste Electrical and Electronic Equipment (WEEE), or e-waste, has gained global relevance, especially with the growing volume of waste generated and the need for sustainable practices. This study proposes and applies a methodology to analyze the disparity between Brazilian legislation and the literature regarding the assignment of responsibilities to stakeholders in the Reverse Supply Chain (RSC). The research, which includes a systematic literature review and content analysis of Brazilian Legal Instruments (BLIs) regarding stakeholders’ responsibilities concerning e-waste in the RSC, reveals gaps between theoretical responsibilities and legal approaches. The comparison between the literature and the BLIs highlights the lack of regulations on practices such as prepayment of waste management fees and the roles of consumers, retailers, and governments in the recycling chain. The study proposes a framework for assigning and sharing responsibilities in the RSC that can serve as a basis for more effective public policies and business strategies, aiming for a more robust circular economy. The conclusions reinforce the importance of greater integration between public policies and RSC practices in Brazil, as well as suggesting updates to the BLIs to promote greater collaboration among the different stakeholders, guaranteeing the effectiveness of reverse logistics systems and sustainability in WEEE management.

Resumen en Portugués:

RESUMO Este artigo teve como objetivos mapear e descrever boas práticas internacionais em logística reversa de embalagens pós-consumo, com foco nas experiências do Canadá, Alemanha e Japão, e discutir sua aplicabilidade no Brasil. A pesquisa foi conduzida por meio de revisão documental sistemática, utilizando a metodologia systematic search flow, com coleta de dados em websites oficiais de órgãos governamentais, entidades gestoras e associações internacionais relacionadas ao tema. Os resultados demonstram que o modelo canadense, com destaque para a província de British Columbia, é estruturado pela responsabilidade total do produtor, operado por uma única entidade gestora, com remuneração baseada em custos reais, contratos de desempenho e aplicação de penalidades em casos de descumprimento. Na Alemanha, o sistema dual impõe ao setor privado a responsabilidade operacional e financeira pela coleta, triagem e reciclagem das embalagens. O modelo alemão destaca-se pela digitalização da rastreabilidade, modulação de taxas por reciclabilidade, educação ambiental estruturada e aplicação de sanções rigorosas. No Japão, o sistema baseia-se na responsabilidade compartilhada com financiamento obrigatório, diferenciação de obrigações conforme o porte das empresas, educação ambiental obrigatória desde o ensino básico, modulação de taxas por desempenho ambiental e regulamentação rigorosa para plásticos descartáveis. Com base nos resultados obtidos, concluiu-se que a replicação parcial e adaptada dessas boas práticas pode contribuir para superar as fragilidades atuais do sistema brasileiro, como a baixa integração institucional, a ausência de padronização nacional, a limitação da fiscalização e a falta de internalização sistemática dos custos ambientais pelos produtores.

Resumen en Inglés:

ABSTRACT This article aimed to map and describe international best practices in reverse logistics for post-consumer packaging, focusing on the experiences of Canada, Germany, and Japan, while discussing its applicability to Brazil. The research was conducted through a systematic document review, using the Systematic Search Flow (SSF) methodology, with data collected from the official websites of local government agencies, management entities, and international associations related to the topic. The results show that the Canadian model, especially in the province of British Columbia, is structured with the full responsibility of the producer, operated by a single management entity, with remuneration based on real costs, performance contracts, and application of penalties in cases of non-compliance. In Germany, the Dual System imposes operational and financial responsibility on the private sector for the collection, sorting, and recycling of packaging. The German model stands out for its digital traceability, modulation of fees for recyclability, structured environmental education, and application of strict sanctions. In Japan, the system is based on shared responsibility with mandatory funding, differentiation of obligations according to the size of the company, mandatory environmental education from primary school onwards, modulation of fees for environmental performance, and strict regulation of disposable plastics. Based on the results obtained, it can be concluded that the partial and adapted replication of these good practices can aid in the current weaknesses of the Brazilian system, such as low institutional integration, the lack of national standardization, limited monitoring, and the lack of systematic internalization of environmental costs by producers.

Resumen en Portugués:

RESUMO O presente trabalho teve como objetivo avaliar a relação do consumo de água com a geração de resíduos sólidos. Para alcançar essa meta, foi utilizada uma abordagem distinta do que é usualmente apresentada. Foi estimado um modelo de regressão quantílica para dados em painel com efeitos fixos por meio do método dos momentos generalizados. Os resultados encontrados mostram que a relação entre o consumo de água e a geração de resíduos extrapola os resultados de modelos de média condicional (regressão linear múltipla convencional). O modelo estimado também identificou efeitos heterogêneos entre os quantis de distribuição da variável dependente, indicando que a associação entre as variáveis é mais forte na parte superior da distribuição. Esses resultados permitem um melhor planejamento da construção da estrutura tarifária pelas agências reguladoras que, se combinado com outros fatores, pode tornar o modelo proposto aperfeiçoado para qualquer município.

Resumen en Inglés:

ABSTRACT This study aims to evaluate the relationship between water consumption and the generation of solid waste. A different approach was used to achieve this goal, through a quantile regression model for panel data with fixed effects, estimated using the generalized method of moments. The results show that the relationship between water consumption and waste generation extrapolates the results of conditional mean models (conventional multiple linear regression). The estimated model also identified heterogeneous effects among the distribution quantiles of the dependent variable, indicating that the association between the variables is stronger in the upper part of the distribution. These results allow for better planning of the construction of the tariff structure by regulatory agencies, which, if combined with other factors, can improve the proposed model for any municipality.

Resumen en Inglés:

ABSTRACT Eco-friendly septic tanks (green pits), a domestic sewage treatment option, represent a social technology based on a decentralized system that promotes the universalization of environmental sanitation. In the Brazilian semiarid, where only 7% of the rural households have an adequate sewage solution, green pits serve the most vulnerable population of the rural settlements. In order to implement this social technology as a social policy, financing institutions demand an investigation on faecal sludge treatment. The present work aims to evaluate the process of sanitizing faecal sludge from green pit systems under the conditions of the Brazilian Semiarid. The study area is the rural settlement ‘25 de Maio’ (Ceará, Brazil), where the sanitation system has been implemented since the mid-2010s and provides zero liquid discharge. The sanitizing process of sludge addressed here was carried out through sun exposure in uncovered drying beds during the dry period of 2020. The analysed faecal sludge samples presented solid consistency and can be considered a stable material with volatile solids to total solids ratio (VS/TS) of under 0.40. Within 45 days of sun exposure, all faecal sludge samples reached a microbiological criterion of E. coli below 3 log MPN/g TS, showing that the hygiene process is efficient, obtaining Class A biosolids in the Brazilian semiarid. It meets the microbiological criteria set by Resolution No. 498/2020 of the National Environmental Council and is, therefore, suitable for safe agricultural use.

Resumen en Inglés:

ABSTRACT Contaminants of emerging concern, which frequently come from pharmaceuticals, personal care products, and industrial waste, pose a significant risk to water quality. Among them, caffeine stands out for being widely used in numerous products in the beverage, food, and supplement industries, and for being frequently detected in surface waters. This work aims to evaluate caffeine adsorption in a fixed-bed column using activated carbon modified with graphene oxide (GO) as an adsorbent. Characterization analysis indicated slight caffeine deposition on the material’s surface after adsorption. The effect of changing caffeine inlet concentration, flow rate, and packed bed height was investigated throughout fixed-bed adsorption tests. The experimental breakthrough curves were modeled using the Thomas and Yoon–Nelson models, exhibiting R2 > 0.96. Results with better removal efficiencies were obtained for a higher caffeine inlet concentration (45 mg L-1) and lower inlet flow rate (4 mL min-1). Overall, the adsorbent exhibited satisfactory results, with caffeine removal over 60% and a maximum experimental adsorption capacity of approximately 93 mg g-1, confirming that activated carbon modified with graphene oxide can be a prominent option for continuous water treatment processes.

Resumen en Portugués:

Resumo Este estudo investigou a resistência mecânica de blocos de terra comprimida incorporando diferentes porcentagens de resíduos de polipropileno/polietileno (PP/PE), até 30%, e poliestireno expandido (EPS), até 7,5%, ao longo de diferentes períodos de cura (7, 14 e 28 dias). Uma análise estatística, incluindo análise de variância multifatorial, foi realizada para avaliar os efeitos da composição do solo e do teor de resíduo na resistência à flexão. Os resultados mostraram que tanto o tipo de solo (A e B) (p < 0,001) quanto o teor de resíduo (p = 0,000) influenciaram significativamente a resistência dos blocos, enquanto o tempo de cura não teve efeito significativo (p = 0,637). O tipo de resíduo polimérico também teve impacto significativo, pois a resistência à flexão dos blocos com EPS foi consideravelmente maior do que a dos blocos com PP/PE (p = 0,002). Especificamente, a formulação de solo T2, que continha 80% de solo B, resultou em uma resistência à tração significativamente menor em comparação com as formulações T0 e T1 (p < 0,001 e p = 0,020, respectivamente). Além disso, a inclusão de 30% de resíduo de PP/PE levou à redução significativa da resistência, enquanto a adição de 5 e 7,5% de resíduo de EPS resultou em aumento significativo da resistência à flexão. Esses achados destacam o papel crucial da formulação de materiais no desenvolvimento de produtos de construção sustentáveis.

Resumen en Inglés:

Abstract This study investigates the mechanical strength of compressed earth blocks (CEBs) incorporating varying percentages of polypropylene/polyethylene (PP/PE) up to 30%, and expanded polystyrene (EPS) up to 7.5%, residues across different curing periods (7, 14, and 28 days). Statistical analysis was performed to evaluate the effects of soil composition and residue content on flexural strength, including a multi-factor Analysis of Variance (ANOVA). The results showed that both soil (A and B) types (p < 0.001) and residue content (p = 0.000) significantly influenced the blocks’ strength, while curing time did not have a significant effect (p = 0.637). The type of polymeric residue also had a significant impact, as the flexural strength of blocks with EPS was significantly higher than those with PP/PE (p = 0.002). Specifically, the T2 soil formulation, which contained 80% of Soil B, resulted in a significantly lower tensile strength compared to the T0 and T1 formulations (p < 0.001 and p = 0.020, respectively). Furthermore, the inclusion of 30% PP/PE residue led to a significant reduction in strength, while the addition of 5% and 7.5% EPS residue resulted in a significant increase in flexural strength. These findings highlight the critical role of material formulation in the development of sustainable construction materials.

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Resumo A contaminação por antibióticos em ecossistemas de água doce é uma preocupação crescente. Este estudo avaliou os efeitos da ampicilina e da oxitetraciclina, individualmente e em combinação, na atividade respiratória microbiana em amostras de água do Rio Coreaú, Ceará, Brasil. Microcosmos respirométricos foram incubados por 28 dias sob exposições de 5, 10 e 25 mg.L-1. Baixas concentrações de antibióticos estimularam a respiração microbiana, indicando uma possível adaptação microbiana e metabolização dos compostos. Em contrapartida, a concentração mais alta de oxitetraciclina suprimiu a atividade microbiana. Em contraste, a mesma concentração de ampicilina aumentou em 88%, sugerindo a presença de cepas resistentes. Misturas dos antibióticos produziram majoritariamente efeitos antagônicos, com frequência estimulando a atividade microbiana além dos níveis observados nos tratamentos individuais. O tratamento A5 × O25 (5 mg.L-1 de ampicilina + 25 mg.L-1 de oxitetraciclina) resultou em um aumento de 262% na captura de CO2 em comparação com o controle, refletindo uma forte resposta hormética. Esses achados demonstram que mesmo concentrações subletais de antibióticos podem influenciar a dinâmica e a resiliência microbiana. Embora as concentrações testadas tenham sido mais altas do que as normalmente reportadas em águas superficiais, os resultados contribuem para a compreensão das potenciais respostas microbianas à exposição a antibióticos e destacam a complexidade das interações dose-resposta em ambientes aquáticos.

Resumen en Inglés:

Abstract Antibiotic contamination in freshwater ecosystems is a growing concern. This study assessed the effects of ampicillin and oxytetracycline, individually and in combination, on microbial respiratory activity in water samples from the Coreaú River, Ceará, Brazil. Respirometric microcosms were incubated for 28 days under exposures of 5, 10, and 25 mg.L-1. The lowest concentrations of antibiotics stimulated microbial respiration, indicating possible microbial adaptation and metabolism of the compounds. Conversely, the highest concentration of oxytetracycline suppressed microbial activity. In contrast, the same concentration of ampicillin enhanced it by 88%, suggesting the presence of resistant strains. Mixtures of the antibiotics generally produced antagonistic effects, often stimulating microbial activity beyond the levels observed in individual treatments. The A5 × O25 treatment (5 mg.L-1 ampicillin + 25 mg.L-1 oxytetracycline) yielded a 262% increase in CO2 capture compared to the control, reflecting a strong hormetic response. These findings demonstrate that even sublethal concentrations of antibiotics can influence microbial dynamics and resilience. Although the concentrations tested were higher than those usually reported in surface waters, the results help understand potential microbial responses to antibiotic exposure and highlight the complexity of dose-response interactions in aquatic environments.

Resumen en Portugués:

RESUMO Nas regiões semiáridas, a ausência de tratamento adequado da água para consumo humano frequentemente dá origem a distúrbios intestinais e, em casos mais graves, a infecções microbianas severas. Nesse contexto, muitas famílias dependem da água de cisterna para suprir suas necessidades de água potável. Este projeto teve como objetivo desenvolver um sistema composto de uma lâmpada emissora de radiação UV-C acoplada a uma bomba de recirculação de água, a fim de garantir a segurança bacteriológica da água de cisternas. O sistema de recirculação foi operado por 6, 12 e 24 horas, e os testes foram realizados com amostras ambientais ou com Escherichia coli ATCC 25922. Os resultados demonstraram que o sistema foi capaz de alcançar 100% de inibição do crescimento de coliformes totais e coliformes termotolerantes após 6 horas de operação. O sistema de baixo custo apresenta potencial para atuar como uma tecnologia social, garantindo a segurança hídrica em regiões semiáridas onde não há sistema público de distribuição de água.

Resumen en Inglés:

ABSTRACT In semi-arid regions, the lack of adequate water treatment for human consumption frequently gives rise to intestinal disorders and, in more severe cases, severe microbial infections. In this context, many households depend on cistern water for their potable needs. This project aimed to develop and use a system composed of an ultraviolet C radiation-emitting lamp coupled to a water recirculation pump to ensure the bacteriological safety of cistern water. The recirculation system was operated for 6, 12, and 24 h, and tests were conducted using environmental samples or with E. coli ATCC 25922. The results demonstrated that the system could achieve 100% inhibition of the growth of total coliforms and thermotolerant coliforms after 6 h of operation. The low-cost system can potentially be a social technology, thereby ensuring water security in semi-arid regions that do not have public water distribution systems.

Resumen en Portugués:

RESUMO Este trabalho teve como objetivo contribuir para a discussão sobre disponibilidade física e acessibilidade econômica dos serviços de abastecimento de água (SAA) para residências localizadas em capitais brasileiras. A base de dados utilizada foi a Pesquisa Nacional por Amostra de Domicílios Contínua realizada pelo Instituto Brasileiro de Geografia e Estatística, referente ao ano de 2022. Disparidades entre regiões foram perceptíveis e famílias chefiadas por mulheres e pessoas não brancas foram as majoritariamente excluídas quanto à conexão física. Parcela significativa de beneficiários de programas de transferência de renda também foi excluída do acesso à água por meio de rede geral. Das famílias conectadas em capitais brasileiras, 16% compromete mais de 3% da renda familiar efetiva com SAA. Por meio da modelação de regressão dos microdados da pesquisa, utilizada a escala do agregado familiar, foi confirmado que famílias chefiadas por mulheres têm maior chance de problemas de acessibilidade econômica. Mesmo com as limitações quanto às bases da pesquisa de renda utilizada, visto que não é específica para os objetivos do trabalho conduzido, ela mostrou-se relevante e oportunizou a coleta de dados, podendo auxiliar o acompanhamento de metas de universalização e de realização do direito humano à água por reguladores e formuladores de políticas.

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ABSTRACT This study aimed to discuss the physical availability and affordability of water supply services (WSS) for households in Brazilian capitals. The database from the Brazilian National Household Sample Survey, conducted by the Brazilian Institute of Geography and Statistics in 2022, was used. The findings reveal significant regional disparities, particularly highlighting that households headed by women and non-white individuals are disproportionately excluded from physical water connections. Additionally, a significant proportion of beneficiaries of cash transfer programs lack access to water through WSS. Approximately 16% of households connected to water services allocate more than 3% of their effective family income to WSS. Regression modeling of the survey’s microdata at the household aggregate level confirms that female-headed households are more likely to face affordability problems. The conclusions guide regulators and policymakers in achieving universal water access goals and promoting the human right to water.

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Abstract The presence of deionized chemical contaminants in waterways poses significant threats to aquatic ecosystems and human populations. This research investigates the efficacy of banana peel (Musa spp.) as a natural adsorbent for treating textile dye-contaminated water. Isotherm and kinetic model types showed that chemisorption was the rate-limiting phase in monolayer adsorption. The maximum adsorption was 28.7 mg/g. Hydroxyl, amine, and carboxyl functional groups detected in the FTIR spectrum provide active sites that promote the adsorption of dye molecules onto the adsorbent. The usual solution eliminated 92.8% of dyes under optimal conditions. The experimental results identified optimal treatment parameters of 0.5 g adsorbent dosage, 7.0 pH, 100 mg/L initial dye concentration, and 60 min contact time. Under these conditions, the system achieved 83.9% dye removal efficiency. While the low dye adsorption capacity in industrial effluent (83.9%) compared to synthetic solutions (92.8%) reflects matrix complexity, banana peels remain effective for real-world textile wastewater treatment. Significantly, a simple acid–base process enables 95% dye recovery, demonstrating both the adsorbent’s reusability and circular economy potential for sustainable water treatment.

Resumen en Portugués:

RESUMO Este estudo investiga as principais barreiras que dificultam a Gestão Integrada e Sustentável de Resíduos (GISR) na Amazônia Brasileira. Empregando uma metodologia estruturada em quatro etapas — (a) revisão sistemática da literatura, (b) desenvolvimento de um instrumento, (c) validação quantitativa utilizando o método Lawshe e (d) interpretação dos resultados — a pesquisa identifica e valida obstáculos-chave específicos para esta região complexa. Uma revisão inicial da literatura identificou 13 barreiras comuns à gestão de resíduos em países em desenvolvimento. A validação por especialistas, utilizando o método Lawshe no contexto amazônico, confirmou 11 como significativamente relevantes, demonstrando um consenso entre pesquisadores locais, profissionais do setor privado e agentes públicos. As duas barreiras restantes apresentaram opiniões divergentes entre os especialistas, possivelmente refletindo percepções diferenciadas dos fatores contextuais e das limitações regionais. Estes resultados destacam a necessidade de compreender os desafios únicos enfrentados pela gestão de resíduos na Amazônia, onde as condições locais impactam diretamente a eficácia das potenciais soluções. As barreiras validadas oferecem insights essenciais para a formulação de políticas públicas e estratégias direcionadas que promovam a sustentabilidade e práticas eficazes de gestão de resíduos adaptadas ao contexto amazônico.

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Abstract This study investigates critical barriers hindering Sustainable and Integrated Solid Waste Management (S-ISWM) in the Brazilian Amazon. Employing a four-stage methodology - (a) systematic literature review, (b) instrument development, (c) quantitative validation using Lawshe’s method, and (d) results interpretation - the research identifies and validates key obstacles specific to this complex region. An initial review of the literature identified 13 common barriers to waste management in developing countries. Expert validation using Lawshe’s method in the Amazonian context confirmed 11 as significantly relevant, demonstrating consensus among local researchers, private-sector professionals, and public-sector agents. The remaining two barriers exhibited divergent expert opinions, potentially reflecting nuanced perceptions of contextual factors and regional limitations. These findings underscore the need to understand the unique challenges involving waste management in the Amazon, where local conditions directly impact the effectiveness of potential solutions. The validated barriers offer essential insights for formulating targeted public policies and strategies that promote sustainability and effective waste management practices tailored to the Amazonian context.

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RESUMO A gestão do lodo de esgoto representa um desafio ambiental significativo na região de Puno, onde o descarte direto nos ecossistemas aquáticos leva à sedimentação, à deterioração da qualidade da água e à redução da eficiência no tratamento de águas residuais. Este estudo teve como objetivo avaliar e comparar a qualidade dos biossólidos produzidos com o lodo de esgoto tratado em lagoas de estabilização nas cidades de Puno, Juliaca e Ilave, utilizando a digestão anaeróbica termofílica. O lodo foi processado em biodigestores durante 30 dias sob temperaturas controladas entre 50 e 60 °C, e foram realizadas análises físico-químicas e microbiológicas para determinar o teor de macronutrientes (nitrogênio, fósforo, potássio), matéria orgânica e a redução de patógenos. Os resultados mostraram as maiores concentrações de nitrogênio (28.336 mg kg-1) e fósforo (7.200 mg kg-1) em Puno, enquanto Juliaca registrou o maior nível de potássio (4.447 mg kg-1). Houve redução significativa de coliformes fecais e ovos de helmintos, atingindo o índice de 2,68 HH/4gST. Os biossólidos dos três locais foram classificados como Classe B, com teores comparáveis de nitrogênio e matéria orgânica, mas com perfis nutricionais específicos de cada local. Conclui-se que a digestão anaeróbica termofílica representa um método sustentável e eficaz para o gerenciamento do lodo de esgoto em áreas alto-andinas, com potencial para produzir biossólidos ricos em nutrientes, adequados para aplicação agrícola.

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ABSTRACT Sewage sludge management is a significant environmental challenge in the Puno region, where direct discharge into aquatic ecosystems leads to sedimentation, deteriorating water quality, and reducing wastewater treatment efficiency. This study aimed to evaluate and compare the quality of biosolids produced from sewage sludge treated in stabilization ponds in the cities of Puno, Juliaca, and Ilave, using thermophilic anaerobic digestion. The sludge was processed in biodigesters for 30 days under controlled temperatures of 50–60°C. Physicochemical and microbiological analyses were performed to determine macronutrient content (nitrogen, phosphorus, potassium), organic matter, and pathogen reduction. Results showed the highest nitrogen (28,336 mg kg-1) and phosphorus (7,200 mg kg-1) concentrations in Puno, while Juliaca recorded the highest potassium level (4,447 mg kg-1). A significant reduction in fecal coliforms and helminth eggs was achieved, reaching an index of 2.68 HH/4gTS. Biosolids from all three sites were classified as Class B, with comparable nitrogen and organic matter content, but with site-specific nutrient profiles. It is concluded that thermophilic anaerobic digestion represents a sustainable and effective method for sewage sludge management in high Andean areas, with the potential to produce nutrient-rich biosolids suitable for agricultural applications.

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Abstract Biological and physicochemical methods are commonly used to remove phosphorus (P) from wastewater; however, these can present limitations. Therefore, this study aimed to evaluate the effectiveness of water treatment plant sludge from the Federal University of Lavras campus and natural zeolite. The chemical composition and pH were analyzed. Two experimental adsorption assays were conducted in phosphate solutions at concentrations of 25, 50, 75, and 100 mg.L-1 P-PO43-, designated as P25, P50, P75, and P100, respectively. In the first test, sludge and zeolite were used in both powdered and granular forms. The second test evaluated combinations of adsorbents: S10Z40, S20Z30, S25Z25, S30Z20, and S40Z10. All experiments were performed in triplicate using 0.5 g of adsorbent in 50 mL of P-PO43-solution, agitated at 70 rpm for four hours in a Wagner agitator. The sludge and zeolite samples consisted mainly of iron (Fe), silicon dioxide (SiO2), and aluminum oxide (Al2O3), and the pH of both ranged from 7.5 to 8.0. The granular sludge adsorbent achieved approximately 97% removal at phosphate concentrations (P75 and P100) in the first assay, while zeolite efficiency was consistent across forms, reaching 96% for P75.The second assay showed reduced efficiency, with approximately 20% removal for P25 (p < 0.05) in both S30Z20 and S40Z10 conditions and 14% for P50. For P75 and P100, combined removal did not exceed 10%. These findings highlighted the individual adsorptive capacities of sludge and zeolite under different particle size conditions when applied independently.

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ABSTRACT This study assesses the impact of a 2015 public–private partnership on sewage system management in a large city in Brazil’s SoutheastRregion, using 14 performance indicators from the National Sanitation Information System for 2007–2014 and 2015–2022. Interrupted Time Series models and complementary tests detected no statistically significant immediate level change at the public–private partnership initiation for ten indicators, while eight indicators improved in the post-intervention trend — most notably treated sewage volumes and urban/total service coverage rates. After adjusting for official inflation, the average sewage tariff increased by 32 percentage points in 2015–2022 compared with 25 percentage points in 2007–2014, alongside higher sector investment, indicating tariff and investment dynamics consistent with service expansion.

Resumen en Portugués:

RESUMO A análise de risco é amplamente reconhecida por sua simplicidade e eficácia na identificação e categorização de ameaças potenciais. Baseia-se em dois critérios essenciais, probabilidade e consequência, permitindo a priorização dos riscos e a adoção de medidas preventivas. Nesse contexto, o presente estudo aplica a metodologia de análise de probabilidade e consequência (P&C), combinada com a interpolação geoespacial, como ferramenta para a avaliação da qualidade da água e a garantia da segurança hídrica no município de Conceição do Araguaia, Pará. Para isso, as etapas metodológicas incluíram a identificação de parâmetros, coletas in loco, quantificação do risco, modelagem geoestatística e validação cruzada. Os resultados identificaram 19 pontos de amostragem classificados entre risco alto e crítico. A análise de validação revelou alta heterogeneidade local, demonstrando que a contaminação é governada por fatores microlocais. Apesar dessa variabilidade, o mapa mostrou-se eficaz na identificação de zonas macroscópicas de vulnerabilidade, otimizando a alocação de recursos ao concentrar as inspeções em aglomerados críticos. A análise demonstrou que os parâmetros pH, nitrito, coliformes totais e E. coli foram os principais fatores de risco na região estudada. Dessa forma, este estudo contribui para o fortalecimento da segurança hídrica ao propor uma abordagem de gestão por zonas, fornecendo subsídios para a implementação de estratégias preventivas voltadas à proteção dos recursos hídricos e da saúde pública.

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ABSTRACT Risk analysis is widely recognized for its simplicity and effectiveness in identifying and categorizing potential threats. It is based on two essential criteria, probability and consequence, allowing for risk prioritization and the adoption of preventive measures. In this context, the present study applies the Probability and Consequence (P&C) analysis methodology, combined with geospatial interpolation, to assess water quality and ensure water security in the municipality of Conceição do Araguaia, Pará. To achieve this, the methodological steps included parameter identification, on-site sampling, risk quantification, geostatistical modeling, and cross-validation. The results identified 19 sampling points classified between high and critical risk. The validation analysis revealed high local heterogeneity, indicating that micro-local factors drive contamination. Despite this variability, the map proved effective in identifying macroscopic zones of vulnerability, optimizing resource allocation by focusing inspections on critical clusters. The analysis showed that pH, nitrite, total coliforms, and E. coli were the main risk factors in the studied region. Thus, this study contributes to strengthening water security by proposing a zonal management approach, providing support for implementing preventive strategies to protect water resources and public health.

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Resumo A gestão adequada do uso do solo em áreas de mananciais evita custos adicionais com o tratamento de água. No entanto, os benefícios econômicos de curto prazo são relativamente modestos, o que frequentemente desestimula os gestores a investir na conservação das bacias hidrográficas. A literatura ainda carece de uma explicação sobre como a qualidade da bacia pode afetar os custos de tratamento da água a longo prazo. Nesse contexto, este estudo utiliza dados operacionais e de qualidade da água de cinco sistemas de tratamento de água localizados em Caxias do Sul, RS, para definir, quantificar e ilustrar o chamado “efeito de curto prazo” sobre a segurança hídrica. Esse efeito refere-se a situações em que pequenas variações de curto prazo nos custos de tratamento escondem altos riscos econômicos no longo prazo. Os resultados revelam que, em um horizonte de curto prazo, uma melhoria de uma unidade no índice de qualidade da água resulta em uma diminuição marginal de apenas 0,0002 USD·m-3 nos custos de tratamento. No entanto, no longo prazo, o efeito cumulativo da degradação da qualidade da bacia hidrográfica pode exigir a implementação de tecnologias de tratamento mais sofisticadas, como a filtração por membranas, aumentando os custos em aproximadamente 83 a 242%. A dependência em apenas dados econômicos de curto prazo pode comprometer o planejamento em segurança hídrica, evidenciando a necessidade de incorporar custos de tratamento de longo prazo na gestão de bacias de captação.

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Abstract It is widely acknowledged that appropriate land use management within watersheds can prevent additional water treatment costs. However, the short-term economic benefits are relatively modest, often discouraging administrators from committing resources to watershed conservation. The existing literature lacks a comprehensive explanation of how watershed quality affects water treatment costs in the long term. Within this context, this study employs operational and water quality data from five drinking water treatment plants in Caxias do Sul, southern Brazil, to define, quantify, and illustrate the “short-term blurring effect” on water security. This effect refers to situations in which small short-term variations in treatment costs mask substantial long-term economic risks. In the short term, results show that a one-unit improvement in the water quality index yields an average reduction of only 0.0002 USD·m-3 in chemical treatment costs. Nevertheless, in the long term, the cumulative effect of watershed quality deterioration may require the adoption of more sophisticated treatment technologies, such as membrane filtration, ultimately augmenting costs by approximately 83 to 242%. These findings demonstrate that reliance on short-term economic indicators can distort water security planning and highlight the need to incorporate long-term treatment costs into watershed management decisions.

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RESUMO O crescente volume de resíduos tem se tornado uma preocupação global, com destaque para os resíduos agroindustriais, como a vinhaça, um efluente gerado em grande escala pela indústria sucroalcooleira. Seu uso contínuo e descontrolado no solo pode causar lixiviação de minerais para corpos hídricos e saturar a capacidade de retenção de água do solo. O processo Fenton tem se consolidado mundialmente no tratamento de efluentes complexos como a vinhaça, devido ao seu baixo custo, eficácia e alinhamento com os Objetivos de Desenvolvimento Sustentável da ONU (ODS). Neste estudo, a reação de Fenton foi aplicada com modelagem estatística, e a proporção ideal de reagentes [Fe2+]:[H2O2] foi de 50%: 75%, alcançando remoção de 78,14% da DQO, 100% da turbidez e significativa redução de nitrogênio, fósforo, potássio e outros contaminantes. A vinhaça tratada também proporcionou aumento da umidade e correção do pH do solo, sem provocar lixiviação, favorecendo a retenção de nutrientes e sua absorção pelas plantas.

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ABSTRACT The increasing volume of waste has become a global concern, with agro-industrial residues, such as vinasse, standing out. Vinasse is a byproduct generated on a large scale by the sugarcane industry. Its continuous and uncontrolled use on soil can cause the leaching of minerals into water bodies and saturate the soil's water retention capacity. The Fenton process has gained prominence worldwide for treating complex effluents like vinasse due to its low cost, efficiency, and alignment with the United Nations Sustainable Development Goals (SDGs). In this study, the Fenton reaction was applied using statistical modeling, and the ideal reagent ratio of [Fe2+]:[H2O2] was determined to be 50%: 75%, achieving 78.14% chemical oxygen demand removal, 100% turbidity reduction, and significant decreases in nitrogen, phosphorus, potassium, and other contaminants. Treated vinasse also improved soil moisture and pH correction without causing leaching, thus enhancing nutrient retention and plant absorption.

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ABSTRACT This study presents an exploratory hydrogeochemical and hydrogeological assessment of arsenic occurrence in groundwater from the municipalities of Carlos Reyles (Durazno Department) and Sarandí Grande (Florida Department), Uruguay. The objective was to characterize local geological, hydrogeochemical, and operational conditions potentially associated with arsenic mobilization in groundwater systems and to generate site-specific baseline information. The research was conducted in two stages: first, secondary data from public supply wells were analyzed together with geological profiles and physicochemical parameters to identify preliminary patterns. In the second stage, groundwater samples from 16 wells were collected and analyzed to support the exploratory assessment. The results indicated that arsenic concentrations above 10 μg/L were associated with different hydrogeological settings in the two study areas, involving Cretaceous sedimentary formations in Carlos Reyles and crystalline basement aquifers in Sarandí Grande. The analysis of secondary data allowed the identification of site-specific hydrogeochemical patterns, including associations between arsenic concentrations and pH, alkalinity, sodium, and nitrate in Carlos Reyles, as well as between arsenic, pumping flow rates, depth, and alkalinity in Sarandí Grande. The results from sampling and physicochemical analyses indicated consistency with the identified patterns in 40–80% of the sampled wells. The findings highlight the complexity of local aquifer systems and the need for detailed, site-specific investigations to understand arsenic mobilization processes. This study provides baseline environmental data and contributes to future research, monitoring, and groundwater management strategies in arsenic-affected regions of Uruguay.

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RESUMO O tratamento de efluentes é uma preocupação contínua. As soluções baseadas na natureza, como wetlands construídos e lagoas de lemnas, têm sido pesquisadas para solucionar esse e outros problemas. Entretanto, não são encontrados estudos que conectem essas duas opções, dadas as suas demandas de implementação. Com isso, o objetivo deste estudo foi avaliar o potencial de utilização do efluente de WC para o cultivo de biomassa proteica de lemnas. A metodologia utilizada foi revisão bibliográfica para caracterizar o efluente dos WC e teste matemático com variação de profundidade e tempo de detenção das lagoas de lemnas. O tempo de detenção hidráulica (TDH) de 15 dias e a profundidade de 0,50 m foram os fatores que apresentaram condições mais favoráveis para a produção de lemnas. Nessa condição, foi possível estimar que 1 g de proteína bruta de lemna corresponde à recuperação de 2.63 L de água virtual por meio do tratamento de efluente. Finalmente, foi possível concluir a viabilidade dos WC como fonte sustentável de nutrientes necessários para o cultivo de proteína de lemnas.

Resumen en Inglés:

ABSTRACT Wastewater treatment is an ongoing concern. Nature-based solutions, such as constructed wetlands and duckweed ponds, have been researched to address this and other issues. However, no studies have been found that connect these two options due to their implementation demands. Thus, the objective of this study is to evaluate the potential of using constructed wetland effluent to produce protein-rich duckweed biomass. The methodology involved a literature review to characterize the effluent from constructed wetlands and a mathematical test that varied the depth and retention time of the duckweed ponds. A hydraulic retention time of 15 days and a depth of 0.50 m were found to provide the most favorable conditions for duckweed production. Under these conditions, it was possible to estimate that 1 g of crude protein corresponds to the recovery of 2.63 L of virtual water through effluent treatment. Finally, it was possible to conclude that constructed wetlands are a feasible, sustainable source of the nutrients necessary for duckweed protein cultivation.

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RESUMO Este artigo apresenta uma análise sistemática e crítica sobre jardins de chuva no cenário global e brasileiro. Uma revisão sistemática de literatura foi conduzida, seguindo o protocolo Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), com análise de 43 artigos publicados entre 2014 e 2024, recuperados das bases ScienceDirect, Web of Science e SciELO. A síntese quantitativa evidencia que a eficiência hidrológica é diretamente proporcional à profundidade do perfil do solo: sistemas otimizados (> 1,2 m) alcançam retenção de volume superior a 80% (contra 44% em perfis rasos), enquanto as taxas de infiltração no Brasil apresentam média de 312 mm/h. Apesar da comprovada eficácia na remoção de poluentes e no controle de escoamento, a revisão identificou lacunas objetivas: a colmatação prematura por sedimentos, a seleção de vegetação por critérios estéticos em detrimento da capacidade radicular de tratamento e a replicação indevida de parâmetros de design de climas temperados para tropicais. O estudo conclui que o Brasil se encontra em estágio de validação experimental, distinto da aplicação consolidada em políticas públicas internacionais. O principal avanço científico deste trabalho reside na proposição de uma agenda de tropicalização das diretrizes de engenharia, enfatizando a necessidade de monitoramento de longo prazo e a integração de ferramentas de modelagem para alcançar resultados técnicos mais robustos.

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ABSTRACT This article presents a systematic and critical analysis of rain gardens in both global and Brazilian contexts. A systematic literature review was conducted, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol, with analysis of 43 articles published between 2014 and 2024, retrieved from the ScienceDirect, Web of Science, and SciELO databases. Quantitative synthesis indicates that hydrological efficiency is directly proportional to soil profile depth: optimized systems (> 1.2 m) achieve volume retention exceeding 80% (compared to 44% in shallow profiles), while infiltration rates reported in Brazil average 312 mm/h. Despite their proven effectiveness in pollutant removal and runoff control, the review identified clear gaps, including premature clogging caused by sediment accumulation, vegetation selection based on aesthetic criteria rather than root-mediated treatment capacity, and the inappropriate replication of design parameters from temperate to tropical climates. The study concludes that Brazil remains at an experimental validation stage, in contrast to the consolidated application of rain gardens in international public policies. The primary scientific contribution of this work lies in proposing a tropicalization agenda for engineering guidelines, emphasizing the need for long-term monitoring and the integration of modeling tools to achieve more robust technical outcomes.