Biblioteca Digital

O processamento têxtil gera grande quantidade de despejos altamente poluidores, contendo valores elevados de carga orgânica, cor acentuada e compostos químicos tóxicos ao homem e ao meio ambiente. Os efluentes têxteis apresentam uma variação muito grande na sua composição devido aos vários tipos de corantes e produtos químicos utilizados e isto faz o seu tratamento ser um problema complexo. Devido a estas implicações, novas tecnologias têm sido buscadas para a degradação ou imobilização destes compostos em efluentes têxteis dentre os quais a combinação de processos oxidativos avançados, redutivo e separação por membranas. Os processos de separação por membranas têm sido cada vez mais aplicados para separação, purificação e concentração de constituintes industriais, principalmente pelo desenvolvimento e eficiência da técnica e redução de custos com o passar dos anos. O processo redutivo utilizando Fe0 é bastante promissor, em função do custo relativamente baixo do ferro metálico e da sua elevada efetividade na degradação de contaminantes ambientais, sendo que após a oxidação do Fe0 a íons Fe2+ e Fe3+ estes íons podem ser aproveitados em sequência nos Processos Oxidativos Avançados (POAs). Os processos oxidativos avançados são tecnologias extremamente eficientes para destruição de compostos orgânicos de difícil degradação. Podem ser consideradas tecnologias limpas...

Os processos industriais são geradores de uma ampla variedade de contaminantes que estão presentes nas águas residuarias. A seleção de processos de tratamento baseia-se nas características do efluente a ser tratado. Neste trabalho investigou-se um efluente tóxico da fabricação de resinas de poliéster. Existem poucas informações na literatura sobre este tipo de água residuaria. Procedeu-se a caracterização do efluente, efetuando-se a avaliação e identificação de constituintes tóxicos presentes no mesmo por meio de uma abordagem orientada por toxicidade. Foi utilizado bioensaio respirometrico em lodo ativado para avaliar a toxicidade do efluente bruto. Então, foram efetuados tratamentos físicos e químicos para fracionamento do efluente, e apos cada um deles, realizou-se o mesmo bioensaio. Dessa maneira, avaliou-se qual técnica de fracionamento foi a mais efetiva na redução da toxicidade. A maior redução de toxicidade foi observada apos o fracionamento do efluente por arraste com ar em pH 11 (62,5 %). Este resultado demonstrou que uma fração significativa da toxicidade do efluente para lodos ativados era causada por compostos orgânicos volatilizados em pH 11. Isso indica que o tratamento do efluente por arraste com ar em pH básico pode ter impacto positivo em um tratamento biológico aeróbio subseqüente. Uma vez determinado o tipo de compostos no efluente que provocam efeitos tóxicos (Compostos Organicos Volateis - COVs)...

This report provides a complete and comprehensive analysis of industrial wastewater management in industrial estates and craft villages in Vietnam. The analysis was conducted in three separate stages: 1) a detailed inventory of industries and industrial activities responsible for the pollution of the Nhue-Day river basin, including industrial zones, industrial clusters, industrial points, craft villages and large-scale stand alone industries. In the Dong Nai river basin, an inventory of the industrial parks is all that exists for now; 2) an institutional and regulatory analysis in the Nhue-Day and Dong Nai river basin provinces; and 3) identification and determination of appropriate interventions for industrial estates and craft villages.

This report provides a complete and comprehensive analysis of industrial wastewater management in industrial estates and craft villages in Vietnam. The analysis was conducted in three separate stages: 1) a detailed inventory of industries and industrial activities responsible for the pollution of the Nhue-Day river basin, including industrial zones, industrial clusters, industrial points, craft villages and large-scale stand alone industries. In the Dong Nai river basin, an inventory of the industrial parks is all that exists for now; 2) an institutional and regulatory analysis in the Nhue-Day and Dong Nai river basin provinces; and 3) identification and determination of appropriate interventions for industrial estates and craft villages.

Wastewater use in agriculture is a growing practice worldwide. Drivers include increasing water stress, in part due to climate change; increasing urbanization and growing wastewater flows; and more urban households engaged in agricultural activities. The problem with this trend is that in low-income countries, but also in many middle-income countries, it either involves the direct use of untreated wastewater or the indirect use of polluted waters from rivers that receive untreated urban discharges. This poses substantial risks, in particular microbial risks to public health. To address these risks, the World Health Organization in 2006 issued new guidelines for the safe use of wastewater.This paper aims to highlight the growing importance of improving wastewater use in agriculture across the spectrum from lower to high-income countries. It presents an innovative approach linking key issues related to different aspects of wastewater irrigation to a country s level of economic development. Based on data presented in the World Bank s World Development Report...

Vietnam is facing the challenge of trying to keep pace with increasing environmental pollution associated with rapid urbanization, especially in the larger cities. Over the past 20 years, the Government of Vietnam has made considerable effort to develop urban sanitation policies, legislations and regulations, and to invest in urban sanitation including wastewater treatment systems. This study is one of three country studies conducted in the emerging countries of Vietnam, the Philippines, and Indonesia as part of the East Asian urban sanitation review. It reviews the effectiveness of the wastewater sector in Vietnam and makes recommendations to the Government on actions to scale up the sector to improve its performance. Lessons that emerge from this study can be considered for the on-going and or the next generation of wastewater systems.

Vietnam is facing the challenge of trying to keep pace with increasing environmental pollution associated with rapid urbanization, especially in the larger cities. Over the past 20 years, the Government of Vietnam has made considerable effort to develop urban sanitation policies, legislations and regulations, and to invest in urban sanitation including wastewater treatment systems. This study is one of three country studies conducted in the emerging countries of Vietnam, the Philippines, and Indonesia as part of the East Asian urban sanitation review. It reviews the effectiveness of the wastewater sector in Vietnam and makes recommendations to the Government on actions to scale up the sector to improve its performance. Lessons that emerge from this study can be considered for the on-going and or the next generation of wastewater systems.

This report analyzes the progress and challenges of 16 countries in the Danube watershed in delivering sustainable water and wastewater services to all, while meeting the European Union environmental acquis communautaire. After putting the services that are being delivered into context, the report analyzes the organization of services in the region and the level of access to services, that is, how well countries are doing in terms of providing access to water and wastewater services for the entire population. It then looks at the performance of the sector, including the quality of services provided and customer satisfaction with it. It also draws a picture of the efficiency of services, including whether they reflect accepted good practices. Finally, it analyzes the financing of services, looking at whether the financing of operation, maintenance, and investments is secured and affordable. The report draws largely from existing public data sources at the national and regional level, and consolidates them into a coherent...

To evaluate and reflect the sustainability of services in the region, an overall sector maturity assessment was done taking into account four main dimensions: access to services, quality of services, efficiency of services, and financing of services. Each of these dimensions is measured through three simple and objective indicators. For each indicator, best practice values are established by looking at the best performers in the region, and countries closest to those best performers are deemed to have a more mature sector. A more complete description of the methodology to assess the sector maturity is included in the annex of the state of the sector regional report from the Danube Water Program. The outcomes of this assessment for the Austrian water sector are presented, which also shows average and best practices in the Danube region. The Austrian sector maturity score is 96, which is significantly higher than the Danube average maturity of 64, and the highest score in the region. The assessment shows that...

To evaluate the sustainability of services in the region, an overall sector assessment has been done taking into account four main dimensions: access to services, quality of services, efficiency of services, and financing of services. Each of these dimensions is measured through three simple and objective indicators. For each indicator, best practice values are established by looking at the best performers in the region, and the countries closest to those best performers are deemed to have a more mature sector. A more complete description of the methodology to assess sector sustainability is included in the annex of the state of the sector regional report from the Danube Water Program. The outcomes of this assessment for the Serbian water sector are presented, which also shows average and best practices in the Danube region. The Serbian sector sustainability score is 61, which is below the Danube average sustainability of 64. The assessment shows that, on average, the country performs well in terms of access to piped water and flush toilets...

To evaluate and reflect the sustainability of services in the region, an overall sector sustainability assessment was done, taking into account four main dimensions: access to services, quality of services, efficiency of services, and financing of services. Each of these dimensions is measured through three simple and objective indicators. For each indicator, best practice values are established by looking at the best performers in the region, and countries closest to those best performers are deemed to have a more mature sector. A more complete description of the methodology to assess sector sustainability is included in the Annex of the State of the Sector Regional Report from the Danube Water Program. The outcomes of this assessment for the Ukraine water sector are shown in Figure 10, which also shows average and best practices in the Danube region. The Ukrainian sector sustainability score is 54, which is below the Danube average sustainability of 64. The assessment shows that, on average, the country performs well in terms of collection ratio and affordability. The main deficiencies of the Ukraine water sector identified through the sector sustainability assessment are investment level...

To evaluate and reflect the sustainability of services in the region, an overall sector sustainability assessment was conducted taking into account four main dimensions: access to services, quality of services, efficiency of services, and financing of services. Each of these dimensions is measured through three simple and objective indicators. For each indicator, best practice values are established by looking at the best performers in the region, and countries closest to those best performers are deemed to have a more mature sector. A more complete description of the methodology to assess sector sustainability is included in the annex of the state of the sector regional report from the Danube water program. The outcomes of this assessment for the Kosovo water sector are presented, which also shows average and best practices in the Danube region. As a result, the Kosovo sector sustainability score is 63, which is close to the Danube average sustainability of 64. The assessment shows that, on average, the country performs well in terms of access to piped water and flush toilets...

In order to evaluate and reflect the sustainability of services in the region, an overall sector sustainability assessment has been established taking into account four main dimensions: access to services, quality of services, efficiency of services, and financing of services. Each of these dimensions is measured through three simple and objective indicators. For each indicator, best practice values are established by looking at the best performers in the region, and countries closest to those best performers are deemed to have a more mature sector. A more complete description of the methodology to assess the sector sustainability is included in the Annex of the State of the Sector Regional Report from the Danube Water Program. The outcomes of this assessment for the Montenegro water sector are displayed, which also shows average and best practices in the Danube region. As a result, the Montenegro sector sustainability score is 59, which is below the Danube average sustainability of 64, and is among the lower scores in the region. The assessment shows that...

Technology and economic development has led to the growth of megacities and urban centres with populations in the millions. Such population expansion and densification increases the strain on wastewater collection and treatment infrastructure, which has been largely based on an end-of-line centralised model. However, in megacities new challenges arise, because provision of suitable sanitation is expensive and it requires infrastructure expansion through construction of extensive sewer networks and larger capacity wastewater treatment plants, which consume more energy. Alternative disposal techniques for solid and liquid waste generated during the treatment process are required, because disposal solutions are decreasing as landfill costs rise and environmental standards are tightened, the latter reducing opportunities for land reuse. Additionally, mass wastewater discharge can have a detrimental impact on the ecology of water bodies and on the health of downstream populations, and requires suitable treatment before disposal. These challenges have the potential to offset the savings that the economies of scale offered by the traditional wastewater collection and treatment systems can impart. The need for affordable and effective wastewater systems in megacities requires the re-evaluation of traditional systems and the re-engineering of water and wastewater transport and resource concepts. Alternative concepts in wastewater collection and treatment...

Conventional biological wastewater treatment generates large amounts of low value bacterial biomass. The treatment and disposal of this excess bacterial biomass, also known as waste activated sludge, accounts for about 40-60% of the wastewater treatment plant operation cost. A different form of biomass with a higher value could significantly change the economics of wastewater treatment. Fungi could offer this benefit over bacteria in wastewater treatment processes. The biomass produced during fungal wastewater treatment has, potentially, a much higher value than that from the bacterial activated sludge process. The fungi can be used to derive valuable biochemicals and can also be used as a protein source. Various high-value biochemicals are produced by commercial cultivation of fungi under aseptic conditions using expensive substrates. Food-processing wastewater is an attractive alternative as a source of low-cost organic matter and nutrients to produce fungi with concomitant wastewater purification. This review summarizes various findings in fungal wastewater treatment, particularly focusing on byproduct recovery during wastewater treatment. This review also provides an overview on performance of fungal treatment systems under various operational conditions. Important factors such as pH...

This thesis study aimed to develop multi-functional nano-catalyst and porous adsorbents from low-cost and locally available materials, and then implement this into an Adsorption-Photocatalysis hybrid system for wastewater reclamation. The project involves two major technological practices for wastewater treatment: adsorption and photocatalysis. For each technology, a specific functional nanomaterial has been developed and investigated regarding their removal capability for a pilot-scale water treatment process. The experimental studies include: 1) evaluation and characterisation of the natural clay minerals that deliver the most suitable properties for adsorption performance and immobilisation of titanium dioxide (TiO₂); 2) synthesis, modification, and characterisation of the clay mixtures as alternative adsorbents, and titania immobilised onto modified porous kaolin as the photocatalyst; 3) evaluation and optimisation of their removal capability, kinetics and mechanisms toward different surrogate indicators of both nanomaterials via the batch and continuous water treatment system; and 4) integration of the adsorption-photocatalysis hybrid system as a major technical outcome for the treatment and reclaimantion of wastewater. Three Australian natural clay minerals...

Effective management of sanitation and wastewater is a growing challenge in dense urban settlements. Rapidly increasing urbanization and, along with that, rising settlement densities in low-income urban and peri-urban areas highlight the need for sanitation technologies and management systems that are robust and affordable, and which lessen the pollution load on local water sources. In many developing countries, centralized sewerage and wastewater treatment systems cover only a portion of larger urban areas, and are often not yet planned for smaller towns and densely populated, low-income areas of cities. On-site sanitation is often inappropriate in the denser settlements and slum areas, thus requiring intermediate and complementary solutions. Decentralized wastewater treatment systems (DEWATS) connected to simplified sewer systems or communal sanitation centers have the potential to close the gap between on-site and centralized systems. Community-managed DEWATS offer the possibility of swift sanitation improvements in high priority neighborhoods that communities can manage themselves...

This primer is concerned with energy use and efficiency of network-based water supply and wastewater treatment in urban areas. It focuses on the supply side of the municipal water cycle, including the extraction, treatment, and distribution of water, and collection and treatment of wastewater-activities which are directly managed by Water and Wastewater Utilities (WWUs). The main challenges to scaling up Energy Efficiency (EE) in municipal water and wastewater services stem from sector governance issues, knowledge gaps, and financing hurdles. Utility governance affects the overall performance of individual WWUs and influences decision making, incentives and actions for energy management. This is likely the most significant barrier to WWU EE in many developing countries. Addressing knowledge gaps requires efforts to systematize data collection, training, and capacity building at utilities, supported by local and national governments. Financing hurdles can be reduced by introducing dedicated EE funds to address large but disaggregated investment needs and by promoting third-party financing through energy/water savings performance contracts. This primer is part of Energy Efficient Cities Initiative's (EECI's) knowledge clearinghouse function to inform World Bank (WB) staff working in urban water supply and wastewater management...

The volume of wastewater generated by domestic, industrial and commercial sources has increased with population, urbanization, improved living conditions, and economic development. The productive use of wastewater has also increased, as millions of small-scale farmers in urban and peri-urban areas of developing countries depend on wastewater or wastewater polluted water sources to irrigate high-value edible crops for urban markets, often as they have no alternative sources of irrigation water. Undesirable constituents in wastewater can harm human health and the environment. Hence, wastewater irrigation is an issue of concern to public agencies responsible for maintaining public health and environmental quality. For diverse reasons, many developing countries are still unable to implement comprehensive wastewater treatment programs. Therefore in the near term, risk management and interim solutions are needed to prevent adverse impacts from wastewater irrigation. A combination of source control, and farm-level and post-harvest measures can be used to protect farm workers and consumers. The WHO guidelines revised in 2006 for wastewater use suggest measures beyond the traditional recommendations of producing only industrial or non-edible crops...