A DEWATS (decentralized wastewater treatment system) is an alternative for expanding sanitation. In Brazil, DEWATS is acknowledged by law and is part of the National Sanitation Plan strategy for achieving the treatment of 85.6% of all the generated wastewater by 2033, improving the current treatment index of 49%. This review's aim is to identify DEWATS studies in Brazil and to verify their potential for narrowing the national wastewater treatment deficit. Hence, aspects such as cost, maintenance, and efficiency were assessed. The archival research method (ARM) was used to identify papers published in the last 20 years through the scientific databases of Scopus, Science Direct, and Web of Science. Data regarding the general characteristics of each study were collected and compared to Brazilian environmental regulation and sanitation status. The results showed the evaluation of different technologies such as DEWATS, highlighting their flexibility and potential use in 79% of Brazilian counties. However, although 81% of the studies conducted performance analysis, none covered the main parameters required by Brazilian law. Although legal gaps for DEWATS improvement and consolidation have been identified and the interest in studying DEWATS has been increasing in the last five years, many barriers to their widespread use remain.

An equitable sanitation coverage promotes sustainability, economic prosperity, and public health protection. This study examined factors affecting sanitation coverage and the potential of selected countries across three income levels (Low-Income, Lower-Middle, and Upper-Middle Income Countries) to meet Sustainable Development Goal 6.2 by developing a Sanitation Coverage Index (SCI). Nine developing countries were selected based on the following sets of criteria: income level, population, and geographical region. Twenty years (2000–2020) of sanitation coverage data were extracted from the JMP database and visualized. The SCI was developed using the service level criteria and examined the local drivers of poor sanitation coverage. Findings show that all countries studied made good progress and have commendable current status, except Ethiopia, Rwanda, and Nigeria. Nigeria has the highest open defecation coverage and may not meet the 2030 target. The SCI result shows that Turkey, Ukraine, and China have excellent coverage (scoring: 44, 43, and 40). Brazil, Bangladesh, and DPR Korea have satisfactory performances (36, 31, and 31), while Nigeria, Rwanda, and Ethiopia recorded unsatisfactory progress (28, 27, and 16). The strongest factors influencing poor coverage include population, high socioeconomic inequalities, and socio-political challenges. Therefore, the institutionalization of minimum acceptable standards, adequate sensitization, and funding could improve sanitation coverage in the countries assessed.

Water treatment sludge (WTS) is the residue produced during water treatment processes for public use. Exploring the reintroduction of these wastes into the production chain to generate new, value-added materials presents a current challenge. This could promote their reuse and reduce the negative environmental impacts associated with their disposal. This study assessed the technical feasibility of using aluminum-based WTS to partially replace silty sand soil in mixtures that include two stabilizers (hydrated lime and Portland cement), potentially for use in road pavements. After conducting a thorough physical, chemical, and geotechnical characterization of both the soil and the sludge, bench-scale experiments were carried out to test the mixtures’ resistance, with WTS proportions of 5%, 8%, 10%, 15%, and 20%, stabilized with either lime or cement. The findings confirm that WTS does not contain potentially toxic elements, according to Brazilian standards, and all tested composites appear suitable for paving. However, the mechanical resistance of the soil–sludge–cement mixtures decreases as the WTS content increases, with an optimum California bearing ratio (CBR) of 41.50% achieved at a 5% WTS addition. Meanwhile, incorporating 15% WTS into soil–sludge–lime mixtures resulted in the highest CBR value of 21.25% for this type of mixture. It is concluded that incorporating stabilizers into soil–WTPS mixtures for road construction allows for an increased percentage of WTPS in silty-sandy soils. Further studies are recommended with different soil types and the addition of fibers to the mixes, to assess the long-term performance of the structure, along with economic and environmental analyses.

Na última década, verificou-se, no Brasil, o aumento do número de programas de Pagamento por Serviços Ambientais (PSA) voltados à conservação quanti-qualitativa de águas nos territórios. Entre as principais demandas de aprimoramento desses programas, está a necessidade de comprovação dos serviços ecossistêmicos prestados. É nesse contexto que o presente trabalho foi desenvolvido com o objetivo de avaliar as diretrizes norteadoras do monitoramento da qualidade das águas em bacias contempladas por PSA, bem como verificar a aplicabilidade dessas medidas para a microbacia do Ribeirão das Couves, em São José dos Campos, São Paulo. Para a realização desta pesquisa, utilizou-se, além da pesquisa bibliográfica exploratória sobre a temática, investigação histórica dos documentos da Secretaria Municipal de Meio Ambiente e análise dos dados mensais de qualidade de água fornecidos pela concessionária municipal. A partir dos resultados foi possível verificar que, na atualidade, as águas do Ribeirão das Couves não atendem aos limites da Classe 1 para o parâmetro Escherichia coli. Em suas diferentes fases, o PSA demanda condições de monitoramento diferenciadas em relação ao número de pontos de amostragem e à frequência das análises. Por fim, mesmo entendendo como essencial a caracterização de todos os parâmetros que compõem o Índice de Qualidade de Águas (IQA), este trabalho evidenciou um conjunto mínimo de indicadores para a avaliação dos incrementos de qualidade de águas em bacias contempladas por PSA.

The management of municipal solid waste (MSW) is a global challenge of a complex nature. The organic fraction of rapidly degrading MSW, which can be recycled via composting provided it is segregated at the source, is an incipient or non-existent practice in low- and middle-income countries. This study aimed to identify the barriers and opportunities for composting MSW based on the perception of local stakeholders through a qualitative and quantitative exploratory case study in the municipality of São José dos Campos (SP). The study identified and interviewed local stakeholders engaged in composting in the territory, surveying the local market for organic agricultural inputs. Education, infrastructure, and social influence were the main factors that led to the decision to start composting. For home composting, the efficiency of generated waste diversion is from 42% to 59%, and management difficulties at the beginning of the practice are recurrent. Engaging people is the main challenge of community initiatives and 32% ended their composting activities due to the COVID-19 pandemic. Vermicomposting can be an opportunity to value organic waste in the local market. The insights gleaned from the perceptions of local stakeholders provide valuable input for more effective planning within a municipal composting scheme.