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- Evaluation of the potential use of water treatment sludge (WTS) as a waterproofing material for waste containment earthworksPublication . Marchiori, Leonardo; Studart, André; Morais, Maria Vitoria; Albuquerque, António; Cavaleiro, VictorIndustrial wastes’ incorrect disposal can cause groundwater and soils contamination. In this aspect, the water treatment sludge (WTS) appears as a potential residue to be valorized within soils in order to enhance wastes’ stabilization while mitigating its environmental impacts. Therefore, geotechnical and chemical evaluations were conducted for assessing WTS’s potential as a waterproofing agent for earth works, considering their impacts on the properties of the analyzed clayey soil for assessing possible soil’ reinforcement through a further investigation. Found results on the WTS characterization have shown a high percentage of fines, which contributes for the reduction of the soil’s plasticity. In addition, its chemical composition is compatible with pozzolanic characteristics while being possible to associate the analyzed WTS with materials already used in earth works. These results indicate a solid beginning for a complete characterization of the WTS and its stabilization within soils as they indicate possible reinforcement of clayey soils and use for liners application, which have yet to be confirmed by in-depth investigations around resistance and permeability properties.
- Urban water reuse in tourism areaPublication . Albuquerque, António; Matos, J.Over the past decades, treated wastewater (reclaimed water) has been used as an alternative to potable water for a range of uses such as irrigation (landscapes, golf courses, and agricultural fields), aquifer recharge, industry applications, stream flow feed- ing, and nonpotable urban applications. In that period, there have been significant advances in reuse technologies, and an increase in the implementation of either rules or guidelines for water reuse. Tourism generates one of the biggest pressures on water needs that coincides with the necessity to manage decreasing water resources more efficiently. As tourism areas continue to grow, pressure on local water sources will continue to increase and significant environmental, economic, and social impacts can arise where local freshwater supplies are limited or are available only with large capital investment. The integration of water reuse in water management strategies will contribute to reducing discharges to receiving waters and reducing reliance on natural water sources to meet water demands. In tourism areas, there are several opportunities for reusing reclaimed water produced from domestic wastewater, stormwater, and graywater. Urban waters can be treated through a variety of physical, chemical, and biological processes in order to produce final reclaimed water for dis- charging into a water stream or for reuse.
- Potential for reuse of tungsten mining waste-rock in technical-artistic value added productsPublication . Gomes, João Castro; Silva, Abílio P.; Peralbo Cano, Rafael; Durán Suárez, Jorge Alberto; Albuquerque, AntónioMining and quarrying activities in Europe generate approximately 55% of total industrial wastes, according to a recent Eurostat report. Most of these wastes are directly dumped on land or deposited in landfill sites. The first solution may lead to negative environmental impacts on land (removal of vegetation, deforestation, land slope changes and increased risk of erosion), water (pollutant transport through surface runoff, soil infiltration and contamination of water resources), may lead to the contamination of agricultural goods and may impose risks on human health. In Portugal, about 20% of industrial waste produced originates from mines and quarries, particularly from Panasqueira mining, one of the largest tungsten mines in the world. Currently, Panasqueira mining generates almost 100 tonnes of waste-rock, per day. Such waste-rock have accumulated over a number of years into very large heaps and it is desirable to seek new economic solutions that can contribute towards their reuse. In this context, this work discusses the potential for reuse of waste-rock piles of Panasqueira tungsten mine, which may be a case statement to be followed. The proposed solution described in this paper consists in developing innovative polymer-based composite materials, obtained from non-contaminated waste-rock tailings. Such materials must have suitable properties for technical-artistic value added applications, such as conservation, restoration and/or rehabilitation of historic monuments, sculptures, decorative and architectural intervention, or simply as materials for building revetments.
- The influence of evapotranspiration on wastewater constructed wetland treatment efficiencyPublication . Albuquerque, António; Bialowiec, Andrzej; Randerson, PeterOwing to low investment and maintenance costs, there has been a growing interest in applying plants in wastewater treatment. Plants commonly used in constructed wetlands (CW) include: cattail, reed, rush, yellow flag, manna grass, and willow. In a CW, application of plants brings several benefits: creating aerobic conditions in the otherwise anaerobic rhizosphere, providing carbon compounds into the rhizosphere, uptaking pollutants (e.g. nutrients and heavy metals) from treated wastewater; improving the hydraulic conditions of wastewater flow through CW beds, and also increasing the available surface for growth of microbial biofilms. Hydrophytes also have great transpiration potential. Numerous studies have shown the importance of evapotranspiration during hot periods in natural wetlands and also in constructed wetlands. Evapotranspiration affects treatment efficiency in CWs: it increases the concentration of dissolved compounds due to decreasing water volume. Therefore, having regard to the mode of operating (VSSW or HSSW), temperature and influent characteristics (e.g. HLR and wastewater influent loads), the removal efficiency calculated as a comparison between initial and final concentration is lower, than expected from mass balance. Given results from systems in colder (Poland) and warmer (Portugal) climate conditions shows that the difference in methodology of removal efficiency calculation is significant, even if the CWs are operating in different modes. Usually, in the literature removal efficiency is expressed on the basis of concentrations, mostly due to lack of flow rate monitoring. Unfortunately, this may seriously underestimate treatment performance of CWs. This study suggests the need for routine monitoring of flow rate, or evaluation of potential evapotranspiration, to estimate removal efficiency of a CW based on mass balance.
- Ambiente e recursos naturaisPublication . Albuquerque, António; Costa, Jorge Cruz; Saraiva, Jorge Gil; Liça, JorgeA queima de combustíveis fósseis (por exemplo carvão, petróleo e gás natural) e outras atividades antropogénicas têm levado a elevadas emissões de monóxido de carbono, dióxido de carbono, óxidos de azoto, dióxido de enxofre, metano e clorofluorcarbonos, gases que, em elevadas concentrações na atmosfera, têm sido responsáveis pelo aumento da temperatura média do globo e consequentes alterações climáticas. Simultaneamente, a desflorestação à escala mundial impede que o carbono em excesso na atmosfera possa ser removido e os incêndios libertam também elevadas quantidades de dióxido de carbono para a atmosfera. A forma mais consensual de enfrentar o problema é através da adoção de medidas mitigadoras, para reduzir as emissões dos gases com efeito de estufa, ou absorver os já emitidos, e de medidas de adaptação para reduzir as consequências futuras das alterações climáticas. O futuro acesso a tecnologias de produção de eletricidade renovável, de pequena potência e a custos competitivos, permite prever a constituição próxima de unidades de mini e microprodução que satisfaçam as necessidades próprias de pequenos consumidores e permitem produzir excedentes que podem ser vendidos localmente através das redes regionais. A relevância do tema e as pressões globais de controle das alterações climáticas, permitem prever modelos de organização da atividade de distribuição de eletricidade acessíveis a produtores locais de energia que, em competição aberta, possam oferecer os seus excedentes às redes locais. Não deixa de ser interessante notar que as barreiras mais importantes a uma implementação maior e mais rápida das energias renováveis e ao recurso de estratégias energéticas baseadas em baixas emissões de carbono sejam políticas e não tecnológicas.
- Hydroponic System: A Promising Biotechnology for Food Production and Wastewater TreatmentPublication . Prazeres, Ana R.; Albuquerque, António; Luz, Silvana; Jerónimo, Eliana; Carvalho, FátimaSeveral regions of the world are suffering from water scarcity and available water pollution. Mediterranean countries (such as Portugal, Spain, Italy, Greece, Tunisia, Israel, and Jordan) do not meet the requirements in terms of quantity that have been increasing in the last decades for the various sectors, due to lack of water resources, winters with low rainfalls, and summers with hot and dry conditions. Agriculture is the leading water-consuming sector (70%–80%), followed by industry and domestic use. However, industrial and domestic uses are considered priorities, conditioning the amount of accessible water for the agriculture sector. the use of reclaimed water should be considered in the integrated water management system to avoid damages to the environment (surface and underground water, soil, fauna, and flora) and public health. The use of wastewater for irrigation should be carefully investigated and planned in terms of proper treatment, treated wastewater quality, volume of treated wastewater used, application method, physicochemical characterization of soil, nutritional needs of plants, distance to existing water sources, risk of animal and human contamination, and others. Environmental and economic gains can be achieved by reusing wastewater if the study, planning, and application are performed in a sustainable basis.
- Analysis of hydrodynamic characteristics of a horizontal subsurface flow constructed wetlandPublication . Albuquerque, António; Bandeiras, RodrigoHorizontal subsurface flow (HSSF) constructed wetlands are widely used for wastewater treatment but there’s still a lack of information on flow characteristics changes throughout the porous bed over time. The continuous growth of roots, the adsorption, sedimentation and precipitation of wastewater compounds and the biofilm release over operation time leads to the development of stagnated areas, the appearance of hydraulic short-circuiting and variations in dispersion conditions, which affect substrate distribution throughout the bed and, therefore, may worsen the overall performance of the system. In order to enable a better understanding of the transport mechanisms throughout the bed, two series of tracer tests were performed in a laboratory HSSF system at the hydraulic loading of 4.7x10-3 m3 m-2 h-1. The first series was executed with the bed without vegetation and the second with the bed already colonized with Phragmites australis after an operation period of eight months at an average organic loading of 12 g m-2 d-1 COD. The magnitude of longitudinal dispersion was estimated both by a curve- fitting technique using the non-linear least square optimization method (LSOM) and using the moment method (MOM) over the advection-dispersion-reaction equation. The flow regime and the extension of dead volumes were estimated by the same curve-fitting technique over the multiple tanks in series model (MTS). The results showed that the development of plants and biomass did not contribute for a significant amount of longitudinal dispersion in the overall media length. However, the dispersion was very strong in the inlet section, where the dead volumes increased approximately 65% within the colonized bed. The flow regime may be considered as plug flow throughout the overall length and the tracer retention was associated with dispersion and internal recirculation and, additionally, for Series II it was associated with the occurrence of clusters of biomass and roots. The MTS better explain the tracer results for the overall media length. The MOM seems to be inadequate for estimating Pe leading to underestimated values when compared with the ones calculated by LSOM.
- Evaluation of the simultaneous removal of organic matter, nitrogen and suspended solids in a SSHF constructed wetland in Capinha, PortugalPublication . Arendacz, Mirosława; Obarska-Pempkowiak, Hanna; Albuquerque, António; Correia, Maria; Borges, MiguelComparing with other countries there is still a lack of experience in applied constructed wetlands for wastewater treatment in Portugal. Among all Mediterranean countries only France and Italy established the guidelines on Constructed Wetlands (CWs). In most of those countries as well as in Portugal there are no specific regulations and design criteria of CWs for the treatment of wastewater [1]. Most of the CWs applied in Mediterranean countries were designed basing on northern countries experience; therefore there is a great need to establish regulations suitable for warm climate conditions. Additionally, the extending popularity of CW systems and a need to make more researches is forced by the Urban Wastewater Treatment Directive (91/271/EEC) and Water Framework Directive (2000/60/EEC), which set the goals to achieve certain standards of discharge water in Europe by the 2015 year. The advantages of CWs application in Portugal are unquestionable: low energy and maintenance requirements, low cost and appropriateness for domestic wastewater treatment for small and rural communities. Moreover, the land availability and temperature are not the limiting factors. As almost 25% of 5 Mirosława Arendacz, Hanna Obarska-Pempkowiak, Antonio Albuquerque, Maria Correia, Miguel Borges the population of central Portugal lives in small and rural agglomerations CWs seem to be very attractive solution. The majority of constructed wetlands in Portugal are designed as surface horizontal flow systems for secondary treatment of municipal and domestic sewage [2, 3]. There is very little date on the treatment efficiency of CWs in Portugal so far, however it had been reported that they show good performance in terms of BOD5 , TSS and lower effectiveness for total P and N removal. High capacity to remove low concentration of organic substances was also observed [2]. Data obtained on the treatment efficiency of CWs in Mediterranean countries also proved good potential of CWs to organic removal (COD, BOD5, and TSS) as well as to ammonia removal, which enabled meeting discharge criteria set by governments [1]. The survey conducted for CWs in Spain reported that the loadings applied for horizontal flow systems were in range of 0.8÷20.3 g BOD5 /m2day and 3÷17 g TSS/ m2day [4]. Data obtained in Spain showed that the average load applied to horizontal flow constructed wetlands is higher that ones cited in the literature and proved that those systems perform very well in terms of organic matter removal comparing to the other European countries [4]. This conclusion could also apply to Portugal due to similar climate conditions, close localization and similar regulations and criteria taken into account for sizing. However, more accurate data must be provided in order to approve it and to establish the most guidelines criteria. The objective of the paper was to evaluate the performance of the subsurface horizontal flow (SSHF) submerged constructed wetland in Capinha, located in the central Portugal, mostly in terms of organic matter (COD), nitrogen forms (total N, ammonia and nitrate) and suspended solids (TSS). The aim of the work was also to study the effect of loads on the removal of above pollutants.
- Tratamento de águas residuais – Operações e processos de tratamento físico e químicoPublication . Monte, Helena Marecos do; Santos, M. T.; Barreiros, Ana Maria; Albuquerque, AntónioA engenharia do tratamento de águas residuais conta já com numerosas obras de vulto em Portugal, como o atestam as grandes ETAR das maiores cidades do país e também as de menor dimensão, que tanto têm contri- buído para a recuperação da qualidade da água dos rios e praias do país. A maioria destas obras cumpre cabalmente a sua função, evidenciando a maturidade dos profissionais deste setor e do ensino nesta temática minis- trado nas escolas de ensino superior portuguesas. É, por isso, um pouco paradoxal, que não exista um livro português sobre o tratamento de águas residuais, obrigando os estudantes e os profissionais do setor a socorrer-se de bibliografia de outros países, nomeadamente em língua inglesa. A presente publicação, inserida na série “Cursos Técnicos” publicada pela ERSAR vem, de certa forma, preencher esta falta. A sua elaboração resulta de um protocolo de colaboração técnico-científica celebrado entre a ERSAR e o ISEL e de outro protocolo celebrado entre o ISEL e a UBI. Trata-se de um texto de caráter eminentemente didático, alicerçado no ensino da unidade curricular de “Estações de Tratamento de Águas Residuais”, ministrada no Curso de Mestrado em Engenharia Civil / Área de Especialização de Hidráu- lica, do ISEL, e que embora mais completo do que aquilo que é possível lecionar numa unidade curricular semestral, procura ser uma obra concisa e bastante prática, que tanto pode ser útil a um estudante como a um pro- fissional que procure recordar ou clarificar conceitos já aprendidos. O tratamento de águas residuais não se cinge apenas ao tratamento da chamada fase líquida, mas inclui também o tratamento das lamas e a deso- dorização da atmosfera de zonas de cheiros mais ofensivos. A panóplia de operações e processos unitários de tratamento de águas residuais é, assim, bastante vasta, resultando em mais de uma trintena de capítulos. Por tal motivo, optou-se por organizar esta publicação em três volumes: o primeiro dedicado a operações unitárias de tratamento, o segundo aos processos de tratamento biológico, tanto os mecanizados como os naturais e o terceiro focado no tratamento de lamas e desodorização de atmosferas com odor desagradável.
- Cork Boiling Wastewater Treatment in Pilot Constructed WetlandsPublication . Gomes, A.C.; Stefanakis, Alexandros; Albuquerque, António; Simões, Rogériomost studies published on the topic of cork boiling wastewater (CBW) treatment or valorization used physico-chemical treatment options rather than biological processes. However, the related costs are high and above those of the biological treatment alternative for wastewaters with similar organic loads but from different sources. Thus, con- structed wetland systems (CWs) can be an alternative to conventional biological treatment systems, namely to activated sludge systems, with the prominent virtues of low construction and operation costs. Until today, there is no study or research published for the treatment of CBW using CW systems. Thus, this investigation is a novelty and included the monitoring over a period of four years of the operation of a horizontal subsurface flow constructed wetland (HSF CW) microcosm-scale system planted with common reeds (Phragmites australis) and filled with light expanded clay aggregates (LECA), as support media for the plants and for biofilm development. The contribution of plants to the treatment was assessed by the comparison with an identical wetland unit without plantation (control bed). After this extended period of operation intended to maximize biomass development and acclimatization, which included stepwise increase of the organic load rate (OLR) up to 8.9 g COD/m2/d, the assessment of the treatment capacity of the system was done by doubling the OLR to 16.4 g COD/m2/d during 200 days.