Remoção, por flotação, de óleo em águas produzidas na indústria de petróleo: eficiência e modelagem do processo

The separation oil-water by the use of flotation process is characterized by the involvement between the liquid and gas phases. For the comprehension of this process, it s necessary to analyze the physical and chemical properties command float flotation, defining the nature and forces over the particles. The interface chemistry has an important role on the flotation technology once, by dispersion of a gas phase into a liquid mixture the particles desired get stuck into air bubbles, being conduced to a superficial layer where can be physically separated. Through the study of interface interaction involved in the system used for this work, was possible to apply the results in an mathematical model able to determine the probability of flotation using a different view related to petroleum emulsions such as oil-water. The terms of probability of flotation correlate the collision and addition between particles of oil and air bubbles, that as more collisions, better is the probability of flotation. The additional probability was analyzed by the isotherm of absorption from Freundlich, represents itself the add probability between air bubbles and oil particles. The mathematical scheme for float flotation involved the injected air flow, the size of bubbles and quantity for second, the volume of float cell, viscosity of environment and concentration of demulsifier. The results shown that the float agent developed by castor oil, pos pH variation, salt quantity, temperature, concentration and water-oil quantity, presented efficient extraction of oil from water, up to 95%, using concentrations around 11 ppm of demulsifier. The best results were compared to other commercial products, codified by ―W‖ and ―Z‖, being observed an equivalent demulsifier power between Agflot and commercial product ―W‖ and superior to commercial product ―Z‖

Utilização de uma coluna de flotação para remoção de compostos orgânicos da água de produção

Innovative technologies using surfactant materials have applicability in several industrial fields, including petroleum and gas areas. This study seeks to investigate the use of a surfactant derived from coconut oil (SCO saponified coconut oil) in the recovery process of organic compounds that are present in oily effluents from petroleum industry. For this end, experiments were accomplished in a column of small dimension objectifying to verify the influence of the surfactant SCO in the efficiency of oil removal. This way, they were prepared emulsions with amount it fastens of oil (50, 100, 200 and 400 ppm), being determined the great concentrations of surfactant for each one of them. Some rehearsals were still accomplished with produced water of the industry of the petroleum to compare the result with the one of the emulsions. According to the experiments, it was verified that an increase of the surfactant concentration does not implicate in a greater oil removal. The separation process use gaseous bubbles formed when a gas stream pass a liquid column, when low surfactant concentrations are used, it occurs the coalescence of the dispersed oil droplets and their transport to the top of the column, forming a new continuous phase. Such surfactants lead to a gas-liquid interface saturation, depending on the used surfactant concentration, affecting the flotation process and influencing in the removal capacity of the oily dispersed phase. A porous plate filter, with pore size varying from 40 to 250 mm, was placed at the base of the column to allow a hydrodynamic stable operation. During the experimental procedures, the operating volume of phase liquid was held constant and the rate of air flow varied in each experiment. The resulting experimental of the study hydrodynamic demonstrated what the capturing of the oil was influenced by diameter of the bubbles and air flow. With the increase flow of 300 about to 900 cm3.min-1, occurred an increase in the removal of oil phase of 44% about to 66% and the removal kinetic of oil was defined as a reaction of 1° order.

OSLERUS OSLERI (COBBOLD, 1876) INFECTION IN MANED WOLF (CHRYSOCYON BRACHYURUS, ILLIGER, 1815)

Oslerus osleri is a small nematode that infects the respiratory tract of domestic and wild canids and is responsible for causing chronic nodular tracheobronchitis. This paper aims to report a case of parasitism by O. osleri in a free-living maned wolf (Chrysocyon brachyurus) that was struck by a motor vehicle. Fecal samples were collected, and the presence of spiral larvae, with S-shaped tails, was observed on flotation. This characteristic was compatible with the Filaroididae Family larvae of O. osleri. Although the animal did not show clinical signs of respiratory system impairment, a tracheobronchoscopy was performed. Semitransparent nodules, 5 mm in diameter, containing adult parasites were observed in the third distal portion of the trachea, cranial to the carina. Larval morphological characteristics and the nodular locations were compatible with an O. osleri respiratory tract infection.

Molecular characterization of Giardia duodenalis in dogs from Brazil

The intestinal protozoan parasite Giardia duodenalis (syn. Giardia intestinalis and Giardia lamblia) is a widespread enteric pathogen in human and domestic animals. This organism is one of the most common parasites in domestic dogs in Brazil. In this study, we determined the occurrence and genetic characterization of G. duodenalis isolated from dogs from south-central São Paulo state, Brazil. A total of 300 fecal samples were collected. Fecal specimens were screened for the presence of G. duodenalis using microscopy (zinc sulfate solution flotation technique) and polymerase chain reaction (PCR) targeting the small subunit ribosomal (SSU-rDNA) and glutamate dehydrogenase (GDH) genes. Genetic characterization was performed using restriction fragment length polymorphisms (RFLP) and sequencing analysis of the GDH gene. In addition, selected samples were further characterized by RFLP and sequencing of the beta-giardin gene. The overall occurrence of G. duodenalis was 17.3% (52/300). The occurrence was higher in stray dogs (28%) than in household dogs (6.25%). of the 36 PCR-positive samples that were selected for genotyping, only dog-specific genotype C (20 isolates), D (11 isolates) and mixed C+D (five isolates) isolates were detected in the study. This study provides current information on the infection rates of G. duodenalis genotypes in canine populations and describes for the first time the presence of mixed infections within host-specific C and D genotypes in dogs in Brazil. These genotypes were widespread and commonly found in domestic dogs living in urban and suburban environments of the studied area and confirmed the endemic status of Giardia in this region.

Ocorrência de larva migrans na areia de áreas de lazer das escolas municipais de ensino infantil, Araçatuba, SP, Brasil

A areia das áreas de lazer de escolas podem constituir vias de transmissão para várias zoonoses parasitárias, representando risco potencial para as crianças que brincam nesses locais. Foi avaliada a ocorrência de agentes de larva migrans em 28 escolas municipais de ensino infantil de Araçatuba, SP. Foram colhidas 535 amostras de areia das áreas de lazer dessas escolas nos meses de janeiro (verão) e julho (inverno) de 1997 para estabelecimento da freqüência de isolamento de larvas e/ou ovos de Ancylostoma spp. e de ovos de Toxocara spp., pelos métodos de centrífugo-flutuação e de Baermann, respectivamente. A presença de larvas de Ancylostoma spp. foi observada, em pelo menos uma das amostras, em 35,7% (10/28) das amostras da primeira colheita (verão) e em 46,4% (13/28) quando da segunda colheita (inverno). Ovos de Toxocara spp. não foram encontrados e a presença de ovos de Ancylostoma spp. foi observada em 0,56% (3/535) das amostras.

Prevalence of intestinal parasites in dogs from São Paulo State, Brazil

The prevalence of gastrointestinal parasites in stray dogs, and dogs with owners was investigated by fecal examinations from 271 dogs employing sedimentation, simple flotation and centrifugation-flotation methods. The centrifugation-flotation method, when compared to simple flotation or sedimentation methods was generally more accurate in the diagnosis of all intestinal parasites, but statistical differences were detected only in relation to Giardia spp. and Cystoisospora spp. (synonym Isospora spp.). The following parasites, with their respective prevalence, were diagnosed in the fecal samples: Ancylostoma spp. (23.6%); Toxocara canis (5.5%); Trichuris vulpis (4.8%); Spirocerca lupi (1.9%); Dipylidium caninum (0.7%); Giardia spp. (12.2%); Hammondia heydorni (2.6%); Cystoisospora spp. (8.5%); and Sarcocystis spp. (2.2%). The prevalence of most parasites was similar for dogs of mixed-breed and for dogs of a defined-breed, except for Cystoisospora spp. and T canis which showed a significantly higher prevalence in mixed-breed dogs. The prevalence of Ancylostoma spp. (17.1%) was significantly lower in stray dogs than in those with an owner (31.9%) and the prevalence of Giardia spp. and Cystoisospora spp. was higher in stray dogs (P < 0.05). No effect of season on the occurrence of the different parasite genera could be observed, except for Ancylostoma spp., for which an increase in the percentage of dogs shedding eggs was observed at the beginning of Summer with a peak occurrence during April and May (Autumn). The prevalence of Ancylostoma spp., T canis, T vulpis, Giardia spp. and Cystoisospora spp. was higher in adult males than in adult females, but significant differences between the two groups occurred only with Giardia spp. Young animals were found to more frequently shed Nematode eggs in feces than adult animals. (C) 2002 Elsevier B.V. B.V. All rights reserved.

Detection of anti-Giardia lamblia serum antibody among children of day care centers

OBJETIVOS: Detectar anticorpos séricos anti-Giardia lamblia entre crianças atendidas em creches e estimar a freqüência de infecção por Giardia lamblia em área endêmica. MÉTODOS: Foram coletadas três amostras de fezes de cada uma das 147 crianças de três creches da rede municipal de Botucatu, SP, com idade variando de 0 a 6 anos, e as amostras foram processadas pelos métodos de sedimentação espontânea e flutuação pelo sulfato de zinco. Amostras de sangue foram obtidas da polpa digital, coletadas em papel de filtro e testadas pelos métodos de imunofluorescência indireta (IFI) e de reação imunoenzimática (Elisa) para pesquisa de IgG anti-Giardia. RESULTADOS E CONCLUSÕES: de um total de 147 crianças, 93 (63,3%) apresentaram cistos de Giardia nas fezes. Dos 147 eluatos testados, 93 (63,3%) e 100 (68%) foram positivos para Giardia em IFI e em Elisa, respectivamente. A sensibilidade de IFI foi de 82% e de Elisa, 72%. Contudo, Elisa foi menos específica (39%) do que IFI (70%). A imunofluorescência indireta apresentou maior concordância com o exame de fezes do que Elisa.

Comparison of three concentration methods for the recovery of canine intestinal parasites from stool samples

The aim of present study was to compare the efficiency of a commercial assay and two conventional methods for fecal concentration in detecting canine gastrointestinal parasites. Fecal samples from 254 dogs were processed by centrifugation-sedimentation (CS), centrifugation-flotation (CF) and a commercial assay for fecal concentration (TF-test (R)). The following parasites were detected: Ancylostoma (37.8%), Giardia (16.9%), Toxocara canis (8.7%), Trichuris vulpis (7.1%), Isospora (3.5%), and Sarcocystis (2.7%). The calculated analytical sensitivity indicated that CF was more accurate (P < 0.01) in detecting Ancylostoma, T. canis, T. vulpis and Giardia infections. However, CF showed significantly higher sensitivity only for Ancylostoma, compared to the other two methods. The kappa index value of diagnostic agreement between TF-test and CF was high for T. canis (83%) and moderate for Giardia (72%) and Ancylostoma (63%). The advantages and limitations of each method were assessed for individual diagnosis and epidemiological investigation. (C) 2010 Elsevier B.V. All rights reserved.

Diagnosis of Giardia infections by PCR-based methods in children of an endemic area

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

On negative flows of the AKNS hierarchy and a class of deformations of a bihamiltonian structure of hydrodynamic type

A deformation parameter of a bihamiltonian structure of hydrodynamic type is shown to parametrize different extensions of the AKNS hierarchy to include negative flows. This construction establishes a purely algebraic link between, on the one hand, two realizations of the first negative flow of the AKNS model and, on the other, two-component generalizations of Camassa-Holmand Dym-type equations. The two-component generalizations of Camassa-Holm- and Dym-type equations can be obtained from the negative-order Hamiltonians constructed from the Lenard relations recursively applied on the Casimir of the first Poisson bracket of hydrodynamic type. The positive-order Hamiltonians, which follow froth the Lenard scheme applied on the Casimir of the second Poisson bracket of hydrodynamic type, are shown to coincide with the Hamiltonians of the AKNS model. The AKNS Hamiltonians give rise to charges conserved with respect to equations of motion of two-component Camassa-Holm- and two-component Dym-type equations.

Characterization of micro-bubble size distribution and flow configuration in DAF contact zone by a non-intrusive image analysis system and tracer tests

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

Método para determinação de distribuição de tamanho de microbolhas (DTMB) em sistemas flotação (FAD) para tratamento de águas utilizando a análise de imagem digital

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

Identification of Eimeria mitis and Eimeria praecox in broiler feces using polymerase chain reaction

There are few reports concerning the epidemiology of Eimeria praecox and Eimeria mitis in Brazil. In the present experiment, the polymerase chain reaction (PCR) was used to identify these species in 156 samples of broiler chicken feces from several Brazilian states and the Federal District. Oocysts present in feces samples were purified by sodium chloride flotation followed by addition of DNAzol reagent (Invitrogen®) for extraction of genomic DNA. DNA was precipitated and stored following DNAzol reagent manufacture's instructions. The primers and PCR conditions were as described by Schnitzler et al. (1999). In the 156 field samples analyzed by PCR, 70 and 45 were positive for E. praecox and E. mitis, respectively. In this study we have shown that DNA extraction using DNAzol followed by PCR can be a useful tool in epidemiological studies, since it provides fast and reliable detection of Eimeria sp. in field samples.

Geofungos no Córrego do Sapateiro, Parque Municipal do Ibirapuera, São Paulo, SP, Brasil

No Córrego do Sapateiro, situado no Parque Municipal do Ibirapuera, na cidade de São Paulo, SP, Brasil, amostras de água (50 mL) na profundidade de 10 centímetros foram coletadas em locais antes (local 1) e depois (local 2) da estação de tratamento de flotação, durante os meses da estação chuvosa e quente (janeiro, fevereiro e março) e da estação seca e fria (junho, julho e agosto) de 2008. Além disso, a temperatura, oxigênio dissolvido, condutividade e pH da água foram medidos com um equipamento Horiba U10. Coliformes totais e fecais foram analisados com o kit Aquatest®. A partir de cada amostra de água, alíquotas de 1 mL foram inoculadas em meio batata-dextrose-ágar, totalizando 10 placas de Petri para cada local de coleta. Após incubação por 10 dias a 22 ºC, as colônias fúngicas foram quantificadas, purificadas e identificadas. Os parâmetros abióticos da água não foram limitantes para a presença de geofungos, sendo influenciados pelo tratamento de flotação. Nos dois locais o número de coliformes totais e fecais foi predominantemente superior a 8 NMP dL-1 durante o período estudado. Vinte e sete táxons de fungos foram obtidos, distribuídos em 136 ocorrências. de acordo com o índice de similaridade de Sörensen, a micota dos dois locais coletados foram consideravelmente diferentes, apesar da semelhança entre o número de táxons e ocorrências. Os resultados indicam que o tratamento da água do Córrego do Sapateiro pelo sistema de flotação possivelmente causa modificações na composição taxonômica e na quantidade de UFC de fungos, ao contrário do que ocorreu com os coliformes totais e fecais, cujos resultados apresentaram-se menos conclusivos.

Nematofauna fitopatogênica de sementes comerciais de forrageiras tropicais

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)