This publication provides guidance to water-sector decision makers and planners on how to deal with the quality dimension of groundwater resources management in the World Bank's client countries. There is growing evidence of increasing pollution threats to groundwater and some well-documented cases of irreversible damage to important aquifers. This guide has been produced in the belief that groundwater pollution hazard assessment must become an essential part of environmental best practice for water supply utilities. The guide is particularly relevant for the World Bank's Latin American and Caribbean Region, where many countries have initiated major changes to modernize their institutional and legal framework for water resources management, but may not yet have considered groundwater at the same level as surface water, because of lack of awareness and knowledge of groundwater issues and policy options.

O carvão vegetal, mesmo sendo produzido e utilizado desde os primórdios da civilização, ainda mantêm insuficiente o conhecimento dos diversos mecanismos da cinética química e da transferência de calor e massa que acontecem durante a carbonização. O que torna importante a identificação da maioria, senão de todos, os parâmetros do processo de carbonização de madeira nas dimensões utilizadas na produção industrial de carvão vegetal é a forma como esses parâmetros podem interagir no transcorrer do processo e na qualidade do carvão produzido. O carvão vegetal, mesmo sob carbonização controlada, não é um composto químico definido, alguns carvões são quase carbono puro, outros devido a processos parciais de carbonização, contem quantidades significativas de oxigênio, hidrogênio e compostos orgânicos. Um sistema ideal de carbonização vegetal deve proporcionar uma adequada condição de trabalho, estabelecendo estratégias para minimizar a duração do ciclo da carbonização, sem alterar o rendimento e a qualidade do carvão produzido. Neste sentido, poucas tecnologias foram desenvolvidas visando melhorar o processo. Variáveis operacionais e mesmo construtivas de um forno, influenciam a qualidade final do produto gerado, sendo a temperatura uma das mais importantes, pois tem influência no aspecto, volume e perdas durante a carbonização, razão por que deve ser precisamente controlada. Através de ensaios termogravimétricos sabe-se que quanto maior a velocidade do aquecimento imposta à biomassa, menor o rendimento em carvão vegetal. Constata-se, também, que sob altas taxas de aquecimento a massa de carvão não estabiliza o seu auto-consumo, mesmo que se tenha atingido a temperatura de encerramento da carbonização. Isto ocorre por que há uma diferença de temperaturas entre o forno e o interior da massa de carvão, diferença esta que é função da taxa de aquecimento e dos mecanismos de transferência de calor e massa no interior da massa de carvão. Assim, a utilização do vapor favorece o processo de resfriamento e agrega rendimento, pois encerra o auto-consumo, alem de favorecer a eliminação de gases de materiais voláteis presentes. Assim sendo, a água por ser uma substância facilmente disponível e pouco agressiva quimicamente, torna-se um veículo que modifica a atmosfera interna do forno, amortece as variações de temperatura e atua como um vetor de transporte da energia térmica, fato que explica a sua disseminação como elemento extintor de incêndios. Assim, no processo de carbonização, para que o resfriamento, utilizando vapor d água, seja bem sucedido, depende das características do vapor e de como e onde ele é aplicado, além da combinação do binômio tempo x temperatura, e sua velocidade de circulação no interior da massa do corpo quente ou em incandescência. A velocidade do vapor que flui através dos orifícios de injeção deve ser conhecida para se maximizar os efeitos resfriamento e abafamento. O tempo é importante, pois quanto mais rápido for carregado o vapor sobre o carvão, menor é o tempo disponível para que um dado volume desse vapor condense-se sobre o carvão. Assim, a transferência de calor do carvão para o vapor aumenta, pois o filme de vapor formado sobre o carvão tem pouca espessura, o que favorece o aumento de sua temperatura interna, dificultando a sua condensação. Considerando que o carvão vegetal representa de 60% a 70% do custo da produção do ferro-gusa, torna-se imprescindível a aplicação de investimentos em pesquisas e em tecnologias na forma de carbonização (HOMMA et alli, 2006). A adoção de soluções de maior produtividade nas formas de carbonização implica em alterações significativas na sistemática vigente no modus operandi adotado no Brasil, pois torna-se necessário a adoção de conceitos e tecnologias agroindustriais modernas e mais eficientes de altos investimentos iniciais mas com ganhos ambientais significativos. Os objetivos gerais foram: a otimização do processo de fabricação de carvão, com o resfriamento da massa de carvão e do forno de carbonização utilizando-se vapor d´água como agente refrigerante; analise de redução do tempo de ocupação do forno; análise de rendimento em número de fornadas/ano. Pelos rendimentos apresentados, alem da redução do tempo de produção e no aumento no numero de fornadas utilizando-se resfriamento do forno (envelope construtivo e massa de carvão vegetal) com a aplicação do vapor d água na base da massa de carvão, o processo se mostrou viável e com resultados significativos. | Charcoal, even being produced and used since the dawn of civilization, still have insufficient knowledge of the different mechanisms of chemical kinetics and heat transfer and mass that occur during the carbonization. What is important to identify the most if not all, the parameters of the carbonization process in the dimensions of wood used in industrial production of charcoal is the way these parameters can interact along the process and quality of coal produced. Charcoal, even under controlled carbonization, there is a chemical compound set, some coals are almost pure carbon, others due to partial processes of carbonization, contains significant amounts of oxygen, hydrogen and organic compounds. An ideal system of coking plant should provide a suitable working condition, establishing strategies to minimize the cycle time of carbonization, without changing the yield and quality of coal produced. In this sense, few technologies have been developed to improve the process. Operating variables and even an oven constructive influence the final quality of the product generated, the temperature of the more important as an influence on the appearance, volume and losses during carbonization, reason why it should be precisely controlled. Through testing thermogravimetric known that the higher the speed of heating required to biomass, the lower the yield of charcoal. There is also that at high heating rates the mass of coal does not stabilize its self-consumption, even if it has reached the temperature of completion of the carbonization. This is because there is a temperature difference between the oven and the inner mass of coal, and such difference is a function of heating rate and the mechanisms of heat transfer and mass within the mass of coal. Thus, the use of steam helps the cooling process and aggregate income, for terminating the selfconsumption, in addition to promote the elimination of gas volatiles present. Thus, the water is a substance readily available and inexpensive chemically aggressive, it is a vehicle that modifies the internal atmosphere of the oven, shock, temperature variations and acts as a vector for transport of thermal energy, which explains its spread as a fire extinguisher. Thus, in the carbonization process, for cooling, using water vapor, to be successful, depends on the characteristics of steam and how and where it is applied, and the combination of binomial time x temperature, and speed of movement within the mass of the body. The velocity of steam flowing through the holes injection must be known to maximize cooling and smothering. Timing is important, because the faster the steam is loaded on coal, the less time available for a given volume of vapor to condense on the coal. Thus, the heat transfer from coal to steam increases because the vapor film formed on coal is the thickness, which favors the increase of internal temperature, making it difficult to condensation. Considering that charcoal represents 60% to 70% of the cost of production of pig iron, it is essential that investment in research and technology in the form of carbonization (Homma et alli, 2006). The adoption of solutions for increased productivity in the forms of carbonization implies significant changes in the system in place in the modus operandi adopted in Brazil, it becomes necessary to adopt concepts and modern agro-technologies and more efficient high initial investment but with gains environmental impacts. The overall objectives was: the optimization of the manufacturing process of coal, with the cooling of the mass of coal and coking furnace using water vapor as coolant; analysis of short-time occupation of the oven; analysis of performance in number of batches per year. The income produced, besides the reduction of production time and increasing the number of heats using the oven cooling (building envelope and mass of charcoal) with the use of water vapor on the dry mass of coal, the process to be viable and meaningful results.

El presente trabajo de tesis fue desarrollado en el Laboratorio de Procesamiento del Instituto de Ciencia y Tecnologia de los Alimentos (ICYTAL). Los objetivos de la tesis fueron construir una torre de relleno de PVC, disenar experiencias did cticas para realizar ensayos de enfriamiento de agua, estableciendo la metodologia y limites de operacion del sistema, para obtener finalmente valores del Coeficiente Volumetrico de Transferencia de Masa en la fase gaseosa Kya y K ga. Para la construccion y operacion de la torre de relleno, se utilizaron materiales de bajo costo disponibles en el mercado local y aparatos existentes en el ICYTAL. La construccion y operacion de la torre de relleno fue realizada en forma experimental, por la necesidad de utilizar los medidores de flujo y equipos disponibles, y de instalar el sistema dentro de un espacio limitado fisicamente. Una etapa importante en la operacion fue la seleccion del relleno m s adecuado para realizar los ensayos de enfriamiento de agua. Una vez seleccionado el relleno, se establecio la metodologia de operacion de la torre como sistema de enfriamiento de agua. Para el c lculo de valores del coeficiente de transferencia de masa, se utilizo una metodologia de diseno basada en la variacion de entalpia del aire y una definicion del coeficiente, basada en la variacion de humedad del aire a traves de la seccion de relleno de la torre. Se probo que la torre de relleno es util para funcionar como un sistema de enfriamiento de agua permitiendo variar los flujos de aire y agua, adem s de la temperatura de entrada de agua a la torre, para obtener valores del coeficiente volumetrico de transferencia de masa en la fase gaseosa. Los resultados de los coeficientes Kya o K ga obtenidos en duplicado permitieron desarrollar ecuaciones, basadas en un modelo no lineal, de los coeficientes en funcion de los flujos especificos de aire seco y agua, las cuales son utiles para el diseno de os sistemas de contacto gas-liquido

Endotherms dissipate heat to the environment to maintain a stable body temperature at high ambient temperatures, which requires them to maintain a balance between heat dissipation and water conservation. Birds are relatively small, contain a large amount of metabolically expensive tissue, and are mostly diurnal, making them susceptible to physiological challenges related to water balance and heat dissipation. We compiled total evaporative water loss (TEWL) measurements for 174 species of birds exposed to different temperatures and used comparative methods to examine their relationships with body size, ambient temperature, precipitation, diet, and diel activity cycle. TEWL in the thermoneutral zone (TNZ) was associated primarily with body mass and activity phase. Larger and more active-phase birds, with their higher metabolic rates, lost more water through evaporation than smaller, resting-phase birds, particularly at higher thermal exposures. However, maximum temperature of the natural habitat became an important determinant of TEWL when birds were exposed to temperatures exceeding the TNZ. Species from hotter climates exhibited higher TEWL. Adaptation to arid climates did not restrict evaporative water loss at thermal conditions within the TNZ, but promoted evaporative water loss at exposures above the TNZ. The TEWL of granivores, which ingest food with low water content, differed little from species with other food habitats under all thermal conditions. The effects of environmental covariates of TEWL were dissimilar across thermal exposures, suggesting no evidence for a tradeoff between water conservation in the TNZ and heat dissipation at exposure to higher temperatures. Thus, birds may be able to acclimate when climate change results in the need to increase heat dissipation due to warming, except perhaps in hot, arid environments where species will need to depend heavily upon evaporative cooling to maintain homeothermy.

El suelo radiante es un equipamiento presente en invernaderos comerciales y utilizado convencionalmente como método de calefacción. En este trabajo, en cambio, se ha realizado una evaluación experimental de la refrigeración de un invernadero mediante el uso del suelo radiante acoplado a una bomba de calor aire-agua. Se ensayaron dos escenarios durante los veranos de 2005 y 2006: ventilación natural + malla de sombreo (escenario control), y ventilación natural + malla de sombreo + suelo radiante acoplado a una bomba de calor (escenario de refrigeración activa). Se calcularon las diferencias entre la temperatura del aire interior y exterior (salto térmico), y se concluyó que a 0,5 m sobre el suelo, el sistema suelo radiante-bomba de calor redujo esta diferencia 1,1 grados C en 2005 y 0,8 grados C en 2006. Ambos escenarios se compararon con el comportamiento de otros sistemas de refrigeración: se concluyó que el escenario de refrigeración activa obtenía un salto térmico (medido a 0,5 m) más favorable incluso que la nebulización. Se diseñó un modelo basado en las curvas de rendimiento de la bomba de calor para predecir la capacidad refrigerante desarrollada por el sistema suelo radiante-bomba de calor. El consumo energético de la bomba de calor fue 104,8 Wh/m cuadrado/d (de 13:00 a 18:00 h) bajo las condiciones de ensayo. Este sistema parece ser apropiado sólo para refrigerar invernaderos bajo ciertas condiciones, para cultivos de alto valor añadido, cultivos de bajo porte, o cuando el coste de inversión no es un factor limitante ya que éste es aproximadamente 38 Euros/m cuadrado. | This paper describes the experimental cooling of a greenhouse in Madrid (Spain) using a radiant heated floor (RHF) coupled to an air-water heat pump (HP). Two cooling scenarios were studied over the summers of 2005 and 2006: natural ventilation + a shading screen (control system), and natural ventilation + a shading screen + an RHF (concrete) coupled to an air-water heat pump (i.e., in cooling mode; nominal power, 34.1 W/squre m). Using the difference between the outside and inside air temperatures, it was concluded that at 0.5 m above the floor the RHF system reduced the temperature by 1.1 deg C in 2005 and 0.8 deg C in 2006. Both cooling scenarios were compared with other cooling technologies: the use of the natural ventilation + shading + RHF gave a smaller air temperature difference than fogging at a height equal to or lower than 0.5 m. A model based on the heat pump performance curves was constructed to predict its power consumption and good predictions of the variation over the day were obtained. The power consumption of the heat pump was 104.8 Wh/square m/d (from 13:00 to 18:00 h) under our test conditions in Madrid. The RHF-HP system may only be appropriate for cooling greenhouses under certain circumstances, e.g., when growing high value crops or when cost is not a limiting factor, as its initial investment cost is about Euros 38/m.

In the unlined Tuxbach water transfer tunnel, running between Hintertux (1,500 m asl) and the Schlegeis Reservoir (Austria), a local geothermal anomaly with temperatures up to 14.6 °C exists. These temperatures are around 3 °C higher than expected, considering the tunnel’s shallow depth, together with its surrounding alpine environment and regional heat flow. This is especially noticeable because the temperatures have remained stable since the tunnel’s construction in 1969, although the tunnel is generally cooling the surrounding rock massive. The objective of this investigation is to explain the origin of the anomaly with hydrogeological methods and to evaluate the hydrogeological properties of the gneisses exposed in the tunnel. The anomaly is caused by the high hydraulic conductivity (~2.5∙10⁻⁵ m s⁻¹) within a narrow shear-zone core, part of the Tux Shear Zones in the Ahorn Gneiss Core. The zone triggers fast groundwater transport over 1.5 km from both sides towards the tunnel. One reason is that the morphology provides thicker overburden with growing distance from the tunnel and therefore higher temperatures on the same horizontal level in the directions of the fault plane. The second explanation is that the narrowness of the shear zone permits effective heat transfer similar to a heat exchanger. No hydrothermal water share is recognizable; instead, mainly cold glacial melt water and snow contribute to the section of the anomaly and all other runouts of the tunnel. Factually based results show the disproportionately high contribution of snow and glaciers to the groundwater recharge in this alpine hard-rock aquifer.

Groundwater cooling (GWC) is a sustainable alternative to conventional cooling technologies for supercomputers. A GWC system has been implemented for the Pawsey Supercomputing Centre in Perth, Western Australia. Groundwater is extracted from the Mullaloo Aquifer at 20.8 °C and passes through a heat exchanger before returning to the same aquifer. Hydrogeological simulations of the GWC system were used to assess its performance and sustainability. Simulations were run with cooling capacities of 0.5 or 2.5 Mega Watts thermal (MWth), with scenarios representing various combinations of pumping rate, injection temperature and hydrogeological parameter values. The simulated system generates a thermal plume in the Mullaloo Aquifer and overlying Superficial Aquifer. Thermal breakthrough (transfer of heat from injection to production wells) occurred in 2.7–4.3 years for a 2.5 MWth system. Shielding (reinjection of cool groundwater between the injection and production wells) resulted in earlier thermal breakthrough but reduced the rate of temperature increase after breakthrough, such that shielding was beneficial after approximately 5 years pumping. Increasing injection temperature was preferable to increasing flow rate for maintaining cooling capacity after thermal breakthrough. Thermal impacts on existing wells were small, with up to 10 wells experiencing a temperature increase ≥ 0.1 °C (largest increase 6 °C).

Thermal springs are widespread in the European Alps, with hundreds of geothermal sites known and exploited. The thermal circulation and fluid outflows were examined in the area around Bormio (Central Italian Alps), where ten geothermal springs discharge from dolomite bodies located close to the regional Zebrù thrust. Water is heated in deep circulation systems and upwells vigorously at a temperature of about 40 °C. Heat and fluid transport is explored by steady and transient three-dimensional finite-element simulations taking into account the effect of the last glaciation, which in the study area was recognized to end around 11,000–12,000 years ago. The full regional model (ca. 700 km²) is discretized with a highly refined triangular finite-element planar grid. Numerical simulations suggest a reactivation of the system following the end of the Last Glacial Maximum. Results correctly simulate the observed discharge rate of ca. 2,400 L/min and the spring temperatures after ca. 13,000 years from deglaciation, and show a complete cooling of the aquifer within a period of approximately 50,000 years. Groundwater flow and temperature patterns suggest that thermal water flows through a deep system crossing both sedimentary and metamorphic lithotypes along a fracture network associated with the thrust system. This example gives insights into the influences of deep alpine structures and glaciations on groundwater circulation that control the development of many hydrothermal systems not necessarily associated with convective heat flow.