Giardia spp. and Cryptosporidium spp. are responsible for a number of outbreaks of gastroenteritis, particularly associated with the consumption of contaminated water. The cysts and oocysts of these protozoa are resistant to environmental variations, as well as to most of the physical, chemical and microbiological processes used in water treatment and sewage plants. This study therefore aimed to detect and evaluate the removal of Giardia spp. and Cryptosporidium spp. in a combined system anaerobic / aerobic Waste Water Treatment Plant (WWTP) located in the city of Blumenau, SC, Brazil. For the study of cysts and oocysts, samples of effluents and sludge from the WWTP were concentrated by filtration using a membrane of cellulose esters and by centrifugation, followed by direct immuno-fluorescence assay (RID) using the Merifluor diagnostic kit. The analysis followed the standards published in APHA (2012) to obtain the physical, chemical and microbiological parameters. High concentrations of Giardia spp. (Max. 900,000 L -1 cysts) were detected in 83.3% of the analyzed points. Oocysts Cryptosporium spp. were detected at high concentrations (max. 300,000 oocysts L -1 ) in 66.6% of the analyzed points. Neither cysts nor oocysts were detected in treated effluent samples. Thus, the combined system of the Garcia WWTP showed a 99.9% efficiency rate for the removal of resistant forms of pathogens, contributing to the reduction of environmental contamination by these pathogens present in the domestic sewage of Blumenau, SC.

Using water or ethanol in fuel oils (including gasoline) results in a very fine atomization of the fuel due to micro-explosions (primary, secondary and tertiary) occurring during combustion. Thus the tiny nano-particles produced during combustion may better follow the flow and less particle impingement on the surfaces (tube walls, blades, etc.) occurs. The emulsion is produced by a device on board the engines using no chemical additives. Since the above engines operate at variable fuel flow rate from idle to full power there is a broad range of flow rates of the two liquids to be mixed. This paper deals with an automatic device that is capable of producing the prescribed injection ratio of the dispersed phase into the variable fuel oil flow rate. A design model has been developed to size the device. An ample description of the model and prototype is presented. Experimental validation of the model has been performed with the results discussed in this paper. The final automatic mixing valve arrangement is presented with the experimental set up. Parametric analyses of results together with the simulations are discussed.

The production of an emulsion by emulsification plant without the addition of chemical additives always requires an injection device of the dispersed phase (water or ethanol) into the continuous phase (fuel oil). In this way, a preliminary mixture of immiscible liquids is produced at the right volume ratio. Such a mixture is processed downstream to have an emulsion with the dispersed phase drop mean diameters less than 4 μm. Since Gas Turbines have a variable fuel flow related to the delivered power, there is the necessity of maintaining a prescribed dispersed phase to continuous phase volumetric ratio when the fuel flow varies. This paper deals with an automatic device that is capable of producing the prescribed injection ratio of the dispersed phase into the fuel oil when the fuel oil flow rate changes. Such a device is developed to be coupled with an emulsification system that provides to break an immiscible part of fluid in a very small drops. The system is for feeding fuel into engines (S.I. Gasoline, Diesel, Gas Turbine combustors) operating at variable loadings i.e variable liquid fuel flow. The mixer (PMD, Pre-Mixer Device) has been presented at ASME Turbo Expo (Montreal 2007) for diesel #2 operating at 25°C with the viscosity being assumed as constant because of its variation is in a reduced range. In this paper, different fuels having different viscosities (diesel oil of different numbers, rapeseed oil, sunflower oil, etc) have been tested. The major modeling aspect concerns with the behavior of the annular orifice that produces a membrane displacement. A bibliographic analysis has been performed and the main results are reported in this paper. Since the architecture of the orifice, its geometry and the flow conditions were not reported in the bibliography, systematic experiments have been performed. Such experiments have been carried on for various liquids having various viscosities for different geometric arrangements and force acting on the membrane. The analysis of results led to formulate models to describe both the discharge flow and effective force coefficients. The paper gives a complete outlook of the experiments and of the above models. The viscosity dependent models have been introduced in to the PMD simulation code. Such models that take the influence of viscosity into account have been developed and some scale-up rules have been established. An amply description of the sizing and scale-up models is presented together with modifications to improve the prototype behavior operated with fluids having different viscosities. Experimental results concerning the influence of viscosity of the continuous phase are presented and widely discussed taking the model as reference.

An innovative Emulsification Engine Feeding System (EEFS) has been developed in the Roma Tre University Fluid Machinery Lab. It is based on an emulsification loop, where fuel and water are fed in real time with the emulsion injection. Thus no chemicals to stabilize water in diesel fuel or ethanol in diesel fuel emulsions, are used. The system assures a sufficient stability level of the emulsion to be injected inside the combustor. Tests carried out on the EEFS, developed for a 250–300 kW gas turbine have shown the good quality of the emulsion in terms of the water droplet diameters and volumetric mixing ratio at the various engine loadings. A water separation section that operates for the duration of the engine shutdown is an unique feature of the EEFS to avoid corrosion during stops.

An innovative Emulsification Engine Feeding System (EEFS) has been developed in the Roma Tre University Fluid Machinery Lab. It is based on an emulsification loop, where fuel and water are fed in real time with the emulsion injection. Thus no chemicals are used to stabilize water in diesel fuel or ethanol in diesel fuel emulsions. The system assures the emulsion stability levels sufficient for the emulsion to be injected inside the engine. Tests carried out on the EEFS, developed for a 6 cylinder, four stroke, 12.88 liter, 382 kW diesel engine, have shown the good quality of the emulsion in terms of water droplet diameters and volumetric mixing ratio, at the various off line tests over emulsion flow rates varying about 2.5 l/h to 150 l/h representative of the idle (2 l/h of fuel) to full load (130 l/h of fuel) conditions with the engine rpm ranging from 500 to 2300. A water separation section that operates for the duration of the engine shutdown is a unique feature of the EEFS to avoid corrosion during stops

The production of emulsions on board of engines in real time with the fuel needs for the actual loading requires the development of a mixer that is capable to give the right volumetric ratio between the dispersed phase (water or ethanol) and the continuous phase (fuel). A Prescribed Mixing Device (PMD) has been developed to follow in real time the fuel request of a Gas Turbine or other engines. Previous investigations have demonstrated the stable steady state behavior at the various fuel flow rates ranging from idle to full load. Moreover, the influence of fuel viscosity variations (due to fuel temperature and quality changes) on the PMD response has been studied. This paper deals with the dynamic behavior of such a PMD. A physical model has been developed and accordingly, an amply series of tests have been carried on to check the PMD response to step and sinusoidal changes in the fuel request. A stable behavior has been evidenced thus the water content of the emulsion produced does not show significant drift in its value versus time.

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