Ecological efficiency in CHP: Biodiesel case

This paper evaluates and quantifies the environmental impact resulting from the combination of biodiesel fuel (pure or blended with diesel), and diesel combustion in thermoelectric power plants that utilize combined cycle technology (CC). In regions without natural gas, the option was to utilize diesel fuel; the consequence would be a greater emission of pollutants. Biodiesel is a renewable fuel which has been considerably interesting in Brazil power matrix in recent years. The concept of ecological efficiency, largely evaluates the environmental impact caused by CO(2), SO(2), NO(x) and particle matter (PM) emissions. The pollution resulting from biodiesel and diesel combustion is analyzed, separately considering CO(2), SO(2), NO(x) and particulate matter gas emissions, and comparing them international standards currently used regarding air quality. It can be concluded that it is possible to calculate the qualitative environmental factor, and the ecological effect, from a thermoelectric power plant utilizing central heat power (CHP) of combined cycle. The ecological efficiency for pure biodiesel fuel (B100) is 98.16%; for biodiesel blended with conventional diesel fuel, B20 (20% biodiesel and 80% diesel) is 93.19%. Finally, ecological efficiency for conventional diesel is 92.18%, as long as a thermal efficiency of 55% for thermoelectric power plants occurs. Crown Copyright (C) 2009 Published by Elsevier Ltd. All rights reserved.

Preference ratios for mercury and other chemical elements in the Madeira River, Brazil

Samples of water, suspended solids, and bottom sediments from the Madeira River, Rondonia state, Brazil, were physically and chemically analyzed to investigate the actual Hg mobilization in the aquatic environment and compare it with that of other heavy metals and elements in the area. Two dimensionless Hg preference ratios were defined, expressing (1) the ratio of Hg and other elements in the liquid phase divided by the ratio of Hg and other elements in bottom sediments (P(l.phase)) and (2) the ratio of Hg and other elements in the particulate matter divided by the ratio of Hg and other elements in bottom sediments (P(s.solids)). These preference ratios are useful for comparing Hg transport in three different phases (liquid, particulate matter, and bottom sediments). They also were applicable to any analyzed elementin the area studied, because they generated an almost constant value when the maximum calculated was divided by the minimum (P(l.phase) = 2931; P(s.solids) = 84) and because of their sensitivity to the dominance of sorption processes by Fe oxides and hydroxides. Mercury could be transported preferentially to other analyzed elements in the particulate phase only if its concentration reached values at least 10(4)-fold higher than those expected or quantified in the area. (C) 2002 Elsevier B.V. Ltd. All rights reserved.

Occupational exposure to paint solvents and particulate material in car repair shops

Aims: We evaluated solvents and total particulates exposures in auto body repair shops together with a search of painter's related complaints. Methods: 26 painters exposures were evaluated by pumped personal sampling; solvents were retained in charcoal sorbent tubes and the particulates in PVC filters. Painter's personal habits and their work characteristics were obtained through a questionnaire, applied in a private interview. For the symptoms the Q16 questionnaire was used, added of questions about complaints during the painting. Results: High exposures were detected during spray painting. For solvents, the TLV-STEL adjusted for the mixtures was surpassed in six evaluations. However, as repaint is a short-term operation, it makes the average concentrations weighed for the work shift lower than the TLV-TWA adjusted for the mixtures. Total particulate concentrations had surpassed the TLV-TWA in four of the evaluations. Symptoms frequency in the Q16 questionnaire was higher for painters than for the controls (Mann-Whitney test U=193; p=0.008), and they showed positive correlations with the age (Spearman r=0.354, t=1.85, p=0.076), the number of years in the profession (Spearman r=0.433, t=2.35, p=0.027) and the alcoholic beverage consumption (Spearman r=0.457, t=2.516, p=0.019). Conclusions: The painting work done at car repair shops can result in high solvent and particulate exposures, although they are short-term operations. Their acute and chronic effects for the painters do not have been clearly evidenced in the present study, continuing deserving multidisciplinary attention.

Air quality and emissions management in the State of São Paulo, Brazil

The São Paulo State has 36 million people, 25 million living in three metropolitan areas. Only the São Paulo Metropolitan Region (SPMR) includes the state capital (São Paulo City) plus 38 cities, where ≈ 18 million people live, affected by frequent episodes of ozone, NOx, and fine particulate matter. In 2003, it was estimated that 15.1% of the SPMR vehicles used ethanol and 70.2% used the local gasoline. Natural gas vehicles have witnessed a booming participation in the last years, mainly through conversion of gasoline cars, and the present fleet is almost one million vehicles. To face the problems generated by light vehicles emissions the Federal Government set a program called PROCONVE - Program of Air Pollution Control from Vehicles - in 1986 and since then until now a significant reduction was reached, but the growth of the fleet hides most of the emission cuts. A discussion covers the evolution of the air pollution management in São Paulo; and innovative tools for air pollution management - both for mobile and stationary sources. This is an abstract of a paper presented at the 98th AWMA Annual Conference and Exhibition (Minneapolis, MN 6/21-24/2005).

2,4-Dichlorophenoxyacetic acid (2,4-D) degradation promoted by nanoparticulate zerovalent iron (nZVI) in aerobic suspensions

Reactive species generated by Fe0 oxidation promoted by O2 (catalyzed or not by ligands) are able to degrade contaminant compounds like the herbicide 2,4-dichlorophenoxyacetic acid. The degradation of 2,4-D was influenced by the concentrations of zero valent iron (ZVI) and different ligands, as well as by pH. In the absence of ligands, the highest 2,4-D degradation rate was obtained at pH 3, while the highest percentage degradation (50%) was achieved at pH 5 after 120 min of reaction. Among the ligands studied (DTPA, EDTA, glycine, oxalate, and citrate), only ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA) significantly enhanced oxidation of 2,4-D. This increase in oxidation was observed at all pH values tested (including neutral to alkaline conditions), indicating the feasibility of the technique for treatment of contaminated water. In the presence of EDTA, the oxidation rate was greater at pH 3 than at pH 5 or 7. Increasing the EDTA concentration increased the rate and percentage of 2,4-D degradation, however increasing the Fe0 concentration resulted in the opposite behavior. It was found that degradation of EDTA and 2,4-D occurred simultaneously, and that the new methodology avoided any 2,4-D removal by adsorption/coprecipitation. © 2013 Elsevier Ltd.

Optical properties of the MoO3-TiO2 particulate system and its use as a ceramic pigment

Mo-doped TiO2 powders were prepared using a dry mixture of TiO2 and MoO3 oxides with several compositions, followed by a calcination step at several temperatures. The resulting oxide system develops yellow and green tones. The XRD patterns showed only traces of MoO 3; however, EDS results, combined with TG/DTA data, confirmed the presence of molybdenum ions, suggesting that the changes in optical properties of the oxide system is due to the incorporation of Mo ions into the TiO 2 matrix, substituting Ti+4 with Mo+6 ions. The band gap decreased with increasing of MoO3 content; on the other hand, the band gap reached a maximum value at about 850°C to 910°C when plotted as a function of the calcination temperature. The glazes produced showed that the oxide system under study is a potential material for use as abinary ceramic pigment. Copyright © 2013 Taylor & Francis Group, LLC.

Efeitos dos poluentes gerados pela queima de biomassa no transporte mucociliar nasal e percepção da qualidade de vida de cortadores de cana

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo da determinação do 1-Nitropireno em material particulado atmosférico

Pós-graduação em Química - IQ

Modelos computacionais fuzzy e neuro-fuzzy para avaliarem os efeitos da poluição do ar

Pós-graduação em Engenharia Mecânica - FEG

Desenvolvimento de um modelo termoeconômico que considera os impactos ambientais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Quantificação de poluentes emitidos durante a queima de biomassa florestal em laboratório

Pós-graduação em Engenharia Mecânica - FEG

Amostragem de poluentes particulados emitidos pela queima de biomassa em correntes confinadas

It is clear today the ever-accelerating search for new fuels that will eventually replace those that will survive in our society, which are fossil fuels. For this reason, a fuel used since the dawn of humanity and much studied since then, considered the generator of clean, renewable energy, can earn more and more space in the power generation sector, which is biomass. We performed two experiments with two different types of biomass, one from the Amazon rainforest and other pine and eucalyptus as waste from the sawmill UNESP Itapeva. In the first experiment, conducted at the Laboratory of Combustion and Propulsion INPE Cachoeira Paulista were conducted three tests in a chimney with a fan creating forced ventilation, where the biomass was burned and deposited on a support beneath the hood. In the second experiment was conducted to analyze the emission of particulate matter using biomass (waste) from the sawmill on the campus of UNESP experimental Itapeva the burning of it in a burner for heating water for a wood oven. In these experiments we used a particle called DATARAM4 sampler that is capable of sampling both outdoors and inside of pipelines, which is the focus of this work. With this equipment it was possible to measure the concentration of particulate matter in all the firings as above, and compare them to levels acceptable in the current law, always trying to analyze the so-called fine particles, which are those with diameters less than 2.5 μm. Using data obtained from the equipment was also possible to evaluate the diametral distribution of particulate matter in question, and verify which phases of the flares in the concentration and the diameters of the particles are the most critical. In this work we concluded that in all firings conducted concentrations of particulate matter were higher than that allowed by the law, and the diameters were found that are more harmful to human health

Estimativa das emissões de monóxido de carbono por veículos automotivos na cidade de Campinas/SP utilizando o modelo CAL3QHCR

Air pollution is an environmental issue worldwide and frequently cause negative effects on population health and ecosystems on cities. The relationship between climate and atmospheric pollution can be used as a surrogate to the intensity of air pollution. The present and quantity of some gases can be used as indicators to air quality: particulate matter (PM), sulfur dioxide (SO2), carbon monoxide (CO), ozone (O3), and nitrogen dioxide (NO2). Among those gases, CO has its major source within the cities, where automobiles are the main emitter. But measure pollutant concentration are challenging, sometimes because the lack of good equipments due to high costs and of the large variability of models that varies in precision, way of measure and distribution of sellers. Modeling are useful when there are an intend to evaluate air pollution, its sources and evaluate scenarios. This work aims to use CAL3QHCR model developed by the U.S Environmental Protection Agency (EPA) to generate predictive surfaces of CO concentration distribution on a site within Campinas city, located in São Paulo state, Brazil. CAL3QHCR model use data urban automobile circulation to generate spatial results for CO distribution. We observed that the pollution concentration was lower on our modeling than the concentrations measured by Companhia Ambiental do Estado de São Paulo (CETESB), the main environmental company on the São Paulo state. Also the correlation between average estimates of our model and the measure by CETESB was weak, indicating that the model used on this study need to be or better parameterized, or the scale we measured of CO emissions need to be rescaled. Although the model failed to correlate to CETESB data, maybe one that explore the estimated emissions distributed within the sites to understand spatial distributions of CO on the regions. Also, the generated information can also be used to other studies, and come to be useful to explain heat island

Impact of maintenance of Macrobrachium rosenbergii de Man, 1879 (Crustacea, Decapoda, Palaemonidae) broodstock on the water used in culture ponds

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The role of clouds in improving the regression model for hourly values of diffuse solar radiation

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)