Marina Sangoi de Oliveira Ilha

Comparação de desempenho hidrológico de sistemas de infiltração de água de chuva: poço de infiltração e jardim de chuva

A ocupacao de areas urbanas produz impactos significativos no equilibrio do balanco hidrico das cidades. Como consequencia da impermeabilizacao de areas edificadas tem-se o aumento do escoamento superficial, que ocasiona maior frequencia de cheias urbanas. Visando diminuir o impacto ocasionado pela ocupacao, solucoes tecnicas compensatorias, fundamentadas em tecnicas de infiltracao de agua pluvial, vem sendo amplamente propostas para os projetos de sistemas prediais. Este trabalho objetiva comparar o desempenho hidrologico de dois sistemas de infiltracao no lote: um jardim de chuva e um poco de infiltracao. Para tanto, foram monitoradas as vazoes de entrada, o volume infiltrado e o volume extravasado durante eventos de chuva simulados. Os sistemas de infiltracao de agua foram implantados em uma area experimental, e o monitoramento dos parâmetros foi feito por meio de sensores de nivel de agua e medidores de vazao de alta precisao. Assim, foi possivel construir os hidrogramas de saida dos sistemas e mensurar a parcela de infiltracao de agua durante a operacao deles. Como resultado avaliou-se a relevância de se considerar a parcela de infiltracao no dimensionamento dos sistemas de infiltracao de agua de chuva. Alem disso, observaram-se um melhor desempenho de amortecimento de pico de vazao do hidrograma no jardim de chuva e maior eficiencia de reducao de volume escoado por parte do poco de infiltracao.

Qualidade da água residuária de usina de concreto para fins de aproveitamento

Efficient water use is one of the most important requirements of cleaner production, and the use of the wastewater from concrete production can be an important means to this end. However, there are no Brazilian studies on the quality of concrete plant wastewater and the activities in which such water can be used. This paper aims to evaluate the quality of concrete plant wastewater and to propose guidelines for its treatment for non-potable applications. Wastewater samples were collected from three points in the studied treatment system, and tests were later performed in the laboratory to evaluate the water quality. The results obtained were compared with the limit values for the quality parameters that have been used for the analysis of the non-potable water supply in Brazil. The results indicate a need to at least add coagulation and pH correction processes to the treatment system.

Qualidade de investimentos no uso de água pluvial: Particles Swarm Optimization para a maximização do valor presente líquido

Analysis of the quality of investments should be part of decision-making for implementing rainwater-harvesting systems in order to evaluate whether investments in environmental impacts mitigation are also attractive from the point of view of investors. Considering discounted cash flow methods, net present value is the best indicator for this analysis, because it allows deciding which is the best between two mutually exclusive projects, and it also presents a simple calculation routine and is easily understood by users. This work aimed at presenting a decision-making analysis tool for rainwater-harvesting systems, which is based on the maximization of net present value, using the Particles Swarm Optimization technique. The decision tool was used to evaluate the quality of the investments for implementing a rainwater-harvesting system, considering a building of the public tax category. Three scenarios of the water bill were considered: current rate structure and increases of 100%, 150% and 200%. All scenarios contemplate two alternatives: with sewage rate corresponding to the rainwater use and no fee. Results illustrate opportunities for investments in rainwater-harvesting systems.

Advanced metering in buildings: strategies for increasing its use

Implementacion de medicion avanzada del consumo de gas y de agua es un desafio permanente en algunos paises en desarrollo. Despues de una revision de la literatura, se identificaron cinco estrategias de medicion avanzada que se podrian implementar para aumentar el uso de la medicion avanzada, considerando a Brasil como un estudio de caso: la transferencia de la propiedad de los instrumentos de medicion de los servicios publicos para los demas usuarios, creacion de un proveedor de servicios de medicion, el desarrollo de un agente de la inspeccion de los sistemas de medicion, el uso de sistemas de prepago operados por condominios e implementar metodos para la transmision de datos de las instalaciones a traves de lectura remota de medidores. Para evaluar la viabilidad de cada estrategia, se entrevisto a catorce expertos de las empresas de servicios publicos y las empresas que participan en la implementacion de sistemas de medicion remotos e individuales. Despues de un analisis de contenido y la validacion de las respuestas de los expertos, se propone estrategias para la implementacion de la medicion avanzada que impliquen acciones relativamente simples y que pueden ser realizadas por los agentes locales que estan participando directamente en las actividades de medicion.

Determination of the Storage Volume in Rainwater Harvesting Building Systems: Incorporation of Economic Variable

Rainwater harvesting has been used as a technique to promote water conservation in buildings, as it substitutes the potable water in activities where the use of potable water is not required. In spite of the surge in interest over recent years, some questions still remain regarding to these systems, mainly what involves the reservoir sizing. There are many methods for this purpose that use different inputs such as: rainwater demand, catchment area, roof material, rainy data (daily or monthly) and dry periods. Even in the Brazilian Standard (ABNT, 2007), there is no consensus as to which method should be used. Table 1 shows the main methods found in the literature and their respective inputs. Mainly in developing countries, actions that promote water conservation must be economically feasible so it can raise the interest in investments. Moreover, urban lots are progressively smaller and more expensive. These variables can restrict the size of the reservoirs used in a rainwater system and this should be considered in their design. This article proposes the use of an optimization technique to find the most adequate volume of rainwater reservoirs i.e. the optimal economical result measured by the Net Present Value (NPV): the Particle Swarm Optimization (PSO). PSO is a population-based technique of stochastic nonlinear functions. Its use was inspired by social behavior in flocking birds or school of fishes (Boeringer, Weiner, 2004). It was used for this optimization process because of its flexibility and because it allows the inclusion of other variables that might interfere with the NPV calculation in any given future. This aspect expands the capacity of data processing without loss of efficiency of the algorithm. In this study, PSO was used to size rainwater reservoirs in four case studies and the results obtained were compared with traditional methods that have been used for this purpose, verifying the improvement of the decision making process.