Increase on incineration capacity and NOx control for air enrichment in the experimental simulation of aqueous residue incineration

An experimental investigation of air enrichment in a combustion chamber designed to incinerate aqueous residues is presented. Diesel fuel and liquefied petroleum gas (LPG) were used independently as fuels. An increase of 85% in the incineration capacity was obtained with nearly 50% O-2 in the oxidant gas, in comparison to incineration with air only. The incineration capacity continues increasing for enrichment levels above 50% O-2 , although at a lower pace. For complete oxy-flame combustion (100% O-2 ), the increase of the incineration capacity was about 110% relative to the starting conditions and about 13.5% relative to the condition with 50% O-2 . The CO concentration measured near the flame front decreases drastically with the increase of O-2 content in the oxidant gas. At the chamber exit, the CO concentration was always near zero, indicating that the chamber residence time was sufficient to complete fuel oxidation in any test setting. For diesel fuel, the NOx was entirely formed in the first region of the combustion chamber. For diesel fuel, there was some increase in the NOx concentration up to 35% of O-2 ; this increase became very sharp after that. From 60 ppm, at operation with air only, the NOx concentration raises to 200 ppm at 35% O-2 , and then to 2900 ppm at 74% O-2 . The latter corresponds to six times more NOx in terms of the ratio of mass of NO to mass of residue, compared to the situation of combustion with air only. For LPG, the NOx concentrations reached 4200 ppm at 80% O-2 , corresponding to nine times more, also in terms of the ratio of mass of NO to mass of residue, in comparison with combustion with air only. Results of different techniques used to control the NOx emission during air enrichment are discussed: (a) variation of the recirculated zone intensity, (b) increase of the spray Sauter mean diameter, (c) fuel staging, (d) oxidizer staging, and (e) ammonia injection. The present paper shows that NOx emission may be controlled without damage of the increase of incineration capacity by the enrichment and with low emission of partial oxidation pollutants such as CO.

Intestinal starch disappearance increased in steers abomasally infused with starch and protein

Steers (379 +/- 10 kg) with ruminal, duodenal, and ileal cannulas were used in a 5 x 5 Latin square digestion trial to quantify and evaluate the relationship between intestinal protein supply and intestinal starch disappearance. Treatments were infusions of 0, 50, 100, 150, or 200 g/d of casein along with 1,042 g/d of raw cornstarch. Abomasal infusions were accomplished by passing tubing and a pliable retaining washer through the reticular-omasal orifice into the abomasum. Steers were fed a 93% corn silage, 7% supplement diet that contained 12% crude protein at 1.65% body weight in 12 equal portions/d. Periods lasted 17 d (12 d for adaptation, 2 d of collections, and 3 d of rest). The quantity and percentage of organic matter and protein disappearance from the small intestine increased linearly (P < 0.03) with infused casein. Greater quantities of starch disappeared with increased casein infusion (P < 0.01). The infusion of 200 g/d of casein increased small intestinal starch disappearance by 226 g/d over the control. Casein infusion did not affect the quantity or percent of organic matter, starch, or protein disappearance in the large intestine. Treatments did not change ruminal ammonia N, ruminal pH, or plasma glucose concentrations. Starch disappearance from the small intestine was increased with greater protein flow to the duodenum of steers.

Preparation and characterization of spherical silica-porphyrin catalysts obtained by the sol-gel methodology

This work describes the synthesis of a first-generation iron porphyrin catalyst entrapped in a silica matrix by the sol-gel route, leading to spherical particles. The catalyst was synthesized by the method of Stober, through hydrolysis and condensation of the alkoxysilane TEOS in a mixture of alcohol, water and ammonia, in the presence of the iron porphyrin Fe(TPP)Cl. The relation between particle morphology and catalytic activity of the different Fe(TPP)-SiO2, obtained using different H2O/silane molar ratios and ammonia concentrations in the xerogel syntheses, was studied.The obtained catalysts were characterized by UV-vis spectroscopy, NMR Si-29. thermogravimetric analysis and transmission electron microscopy. Their ability to catalyze (Z)-cyclooctene epoxidation and cyclohexane oxidation was tested using iodosylbenzene as oxygen donor; the oxidation products were analyzed by gas chromatography and the catalysts obtained in a form of particles spherical and monodispersed showed to be a promising catalytic system for selective oxidation. (c) 2005 Elsevier B.V. All rights reserved.

Influence of condensed tannins from Brazilian semi-arid legumes on ruminal degradability, microbial colonization and ruminal enzymatic activity in Saanen goats

The present study aimed at determining the influence of condensed tannins present in the Brazilian legume species Mimosa hostilis, Mimosa caesalpinifolia and Bauhinia cheilantha on ruminal degradability, microbial colonization and enzymatic activity. Polyethylene glycol (PEG) was used to reduce the astringency and concentration of soluble condensed tannins. Four ruminally-cannulated Saanen goats (60 +/- 8 kg BW) were fed, in two experimental periods, with a hay diet based on the studied legumes treated or non-treated with PEG. Voluntary intake, microbial colonization, DM, CP, NDF, and ruminal degradability of PEG treated and non-treated forage leaves, as well as pH, ammonia and 1,4 P-endoglucanase activity of the rumen content were evaluated. Astringency and soluble tannin concentration of the studied legumes were reduced by approximately 70% and 50%, respectively, with PEG treatment. Average DM intake was higher for the treated diet (16.76 g DM/kg BW/day against 13.06 g DM/kg BW/day). Percentile values for degradation parameters and for potential and effective degradabilities of DM, CP and NDF were also affected by the tannins, but at different intensities. Electron microscopic observations of ruminally-incubated legume leaves showed a more effective microbial colonization of PEG-treated leaves for all legume species. A decrease in pH and an increase in ammonia concentration and in endoglucanase activity in the ruminal content was also observed for PEG-treated diets at all sampling periods. Condensed tannins of the studied legume species have influenced the adhesion conditions, colonization and enzymatic activity of the microbial ecosystem, and consequently the ruminal degradation of the different dietary fractions. For this reason, the reduction in condensed tannin would be of great importance to improve the nutrition of ruminant feeding of these species. (c) 2005 Elsevier B.V. All rights reserved.

pncA mutations in pyrazinamide-resistant Mycobacterium tuberculosis clinical isolates from the southeast region of Brazil

Objectives: To investigate the presence of mutations in the pncA gene in 31 pyrazinamide-resistant Mycobacterium tuberculosis and 5 susceptible strains. MICs and pyrazinamidase (PZase) activity were also determined.Methods: All 36 M. tuberculosis clinical isolates were genotyped by mycobacterial interspersed repetitive units (MIRUs) and most were also typed by spoligotyping. The MIC value necessary to inhibit 99% of the resistant mycobacterial isolates was determined by microplate Alamar Blue assay (MABA) and by Lowenstein-Jensen assay (LJA). The PZase activity was measured by pyrazinamide deamination to pyrazinoic acid and ammonia, and the entire pncA sequence including the 410 by upstream from the start codon was determined by DNA sequencing of purified PCR products.Results: of the 31 isolates resistant to pyrazinamide, 26 (83.9%) showed at least one mutation in the pncA gene or in its putative regulatory region: Among the 22 different mutations detected in the pncA gene and in its regulatory region, 9 (40.9%) mutations (consisting of six substitutions, two insertions and one deletion) have not been described in previous studies. Three pyrazinamide-resistant isolates, confirmed by MIC varying from 800 to 1600 mg/L, carried the wild-type pncA sequence and retained PZase activity.Conclusions: These results contribute to the knowledge of the molecular mechanism of pyrazinamide resistance in Brazil and also expand the profile of pncA mutations worldwide. The MABA was successfully used to determine the MICs of pyrazinamide.

Chemical Composition and fermentative characteristics of Elephant grass (Pennisetum purpureum Schum.) silages added of increasing levels of mango (Mangifera indica L.) byproducts

Aiming at evaluating the use of those byproducts on ruminant feeding an experiment has been carried out in the Forage Research department (www.npf.ufc.br), in order to evaluate the effects of addition of increasing levels of mango processing byproducts (MB) in Elephant grass silages. Twenty experimental silos made of PVC pipe (100 x 340 mm), in a completely randomized design with 5 levels of addition (0; 5; 10; 15; and 20%) of MB and 4 replications. Upon 32 days of ensilage, samples were collected for determination of levels of dry Matter (DM), crude protein (CP), ethereal extract (EE), neutral detergent fiber (NDF), acid detergent fiber (ADF), hemicelluloses (HC), ammonia nitrogen (N-NH3), and pH values. Data were evaluated by analyses of variance and regression analyses using the F test at the 5% level. The levels of DM and CP increased of 0.50 and 0.03 percentage units, respectively, for every 1% of MB added. The levels of NDF and ADF decreased of 0.51 and 0.24 percentage units, respectively, for every 1% of MB added. The levels of N-NH3 decreased from 4 to 23 percentage units while pH values remained constant (p>0.05), with average values of 3.29. Addition of 20% of MB improved silages chemical composition by promoting an increase in the levels of MS and reduction in the levels of fiber.

Protein-energy status and 15N-glycine kinetic study of child a cirrhotic patients fed low- to high-protein energy diets

In five male cirrhotic patients (Child A) and in four age- and sex-matched healthy control subjects, whole-body protein turnover was measured using a single oral dose of N-15-glycine as a tracer and urinary ammonia as end product. Subjects were studied in the fasting and feeding state, with different levels of protein and energy intake. The patients were underweight and presented lower plasma transthyretin and retinol-binding protein levels. When compared with controls, the kinetic studies showed patients to be hypometabolic in the fasting (Do) state and with the control diet [D-1 = (0.85 g of protein/154 kJ). kg(-1). day(-1)]. However, when corrected by body weight, the kinetic differences between groups disappeared, whereas the N-retention in the feeding state showed better results for the patients due mainly to their efficient breakdown decrease. When fed high-level protein or energy diets [D-2 = (0.9 g protein/195 kJ) and D-3 = (1.56 g protein/158 kJ). kg(-1). day(-1)], the patients showed D-0 = D-1 = D-2 < D-3 for N-flux and (D-0 = D-1) < D-3 (D-2 is intermediary) for protein synthesis. Thus, the present data suggest that the remaining mass of the undernourished mild cirrhotic patients has fairly good protein synthesis activity and also that protein, rather than energy intake, would be the limiting factor for increasing their whole-body protein synthesis.

Valor nutritivo do feno de Brachiaria decumbens Stapf cv. Basilisk submetido a tratamento com amônia anidra ou uréia

The effects of the ammoniation of Brachiaria decumbens hay was evaluated. The hay bales were distributed into a complete randomized block design, with four replications and they were submitted to the treatments: untreated or treated with anhydrous ammonia (NH3)(2,0 and 3,0% of the DM) or with urea (3,6 and 5,4% of the DM). All the hays bales remained under plastic cover for 45 days. After three days of aeration, samples were collected for the determination of the chemical composition, nitrogenous compounds fraction and the in vitro dry matter (IVDDM) and organic matter (IVDOM) digestibility. In the metabolic study, Saanen goats breed was used in a 5x5 Latin squares design, where the apparent digestibility, the voluntary intake and the nutritive value index were evaluated. The ammoniation increased the contents of the total N, N ammonia (N-NH3) and non-protein N, with high effect on the levels of 3,0% of NH3 and 5,4% of urea. There were no differences between the level of 3,0% of NH3 and 5,4% of urea for the total N, N-NH3 and NPN. However, the treatment with 3,0% of NH3 allowed a larger fixation of N in ADIN and NDIN forms. The ammoniation increased the IVDMD and IVDMO and reduced the contents of neutral detergent fiber (NDF), hemicellulose, acid detergent fiber (ADF) and lignin, but it did not alter the cellulose and gross energy contents. The ammoniation increased the DM, OM, CP, NDF, ADF, hemicellulose, cellulose and gross energy apparent digestibility and as well as the voluntary intake of DM, digestible DM, digestible OM, digestible protein, digestible energy and the nutritive value index. The ammoniation increased the hay nutritive value index, but there were no differences between the levels of NH3 and urea.

Sources of atmospheric acidity in an agricultural-industrial region of São Paulo State, Brazil

[1] Surface-based measurements of atmospheric formic acid (HCOOH), acetic acid (CH3COOH), sulfur dioxide (SO2), hydrogen chloride (HCl), and nitric acid (HNO3) were made in central São Paulo State, Brazil, between April 1999 and March 2000. Mean concentrations were 9.0 ppb (HCOOH), 1.3 ppb (CH3COOH), 4.9 ppb (SO2), 0.3 ppb (HCl), and 0.5 ppb (HNO3). Concentrations in sugar cane burning plumes were 1160-4230 ppb (HCOOH), 360-1750 ppb (CH3COOH), 10-630 ppb (SO2), 4-210 ppb (HCl), and 14-90 ppb (HNO3). Higher ambient concentrations of SO2, HCl and HNO3 were measured during the burning season (May-November). Concentrations of SO2 and HCl increased during the evening, and of HCOOH and CH3COOH were lowest in the morning, with peak levels in the afternoon. Ratios obtained between different species showed either nighttime maxima (SO2/HCOOH, SO2/CH3COOH, SO2/HNO3, CH3COOH/HNO3, SO2/HCl and HCOOH/HNO3), daytime maxima (HCOOH/HCl, CH3COOH/HCl and HNO3/HCl), or no clear trends (HCOOH/CH3COOH). Correlation analysis showed that SO2 and HCl were primary emissions from biomass burning and road transport; HCOOH, HNO3 and CH3COOH were products of photochemistry; HCOOH and CH3COOH were emitted directly during combustion as well as from biogenic sources. Biomass burning affected atmospheric acidity on a regional scale, while vehicular emissions had greater impact in urban and adjacent areas. Atmospheric ammonia levels were insufficient to neutralize atmospheric acidity, which was mainly removed by deposition to the surface.

Relação Cálcio/Fósforo Disponível em Rações para Tilápia do Nilo (Oreochromis niloticus)

The objective of this work was to evaluate the effect of Ca: available P (P-a) ratio in the diets on performance and bone mineral depositions of juvenile Nile tilapia (2.5 +/- 0.5g). Seven isoproteic and isoenergetic diets (28% CP and 3100 Kcal of DE/Kg of diet), with similar crude fiber and sulfur aminoacids content, were used. The diets had 0.50 and 0.25; 0.50 and 0.50; 0.50 and 0.75; 0.80 and 0.40; 0.80 and 0.80; and 0.80 and 1.20% of Ca and P-a which corresponded to Ca/P-a ratios of 2:1;1:1 and 1:1.5, respectively. An additional control diet, with low levels of Ca and Pa (0.02 and 0.12%, respectively) was used. A completely randomized design with a 2'3 factorial arrangement (Ca level and Ca:P-a ratio) on treatments, plus the additional control diet and three replications was used. Five fishes per aquaria were randomly allotted to 21 fiberglass aquaria (80L). The temperature of the water was maintained close to 26degreesC, and the oxygen, pH and ammonia levels of the water were monitored. The results showed that it was necessary a minimum dietary level of 0.25% of P-a for a satisfactory bone mineral depositions, and that the best performance results were achieved using diets with Ca: P-a ratios between 1:1 and 1:1.5.

Preservação do Feno de Brachiaria decumbens Stapf cv. Basilisk Submetido a Tratamento com Amônia Anidra ou Uréia

This study was conducted to evaluate the effects of anhydrous ammonia (NH3) or urea treatment on the occurrence of fungi in hays of Brachiaria decumbens Stapf cv. Basilisk, baled and stored with different moisture contents. The following treatments were evaluated: T-1 = green forage, soon after the harvest; T-2 = hay with 25% of moisture, with evaluation before baling; T-3 = hay with 13% of moisture and untreated; T-4 = hay with 25% of moisture + .5% of NH3 in the DM T-5 = hay with 25% of moisture +1% of NH3 in the DM; T-6 = hay with 25% of moisture +.9% of urea in the DM and T-7 = hay With 25% of moisture +1.8% of urea in the DM. The treated hays stayed under plastic cover during 75 days, and samples were collected soon after the opening of the bales piles,and they were immediately analyzed in the laboratory. Eleven fungi were identified in different treatments, with high incidence of Aspergillus in the untreated hay, in the hay stored with 25% of moisture and treated with .5% NH3. The ammoniation totally reduced the occurrence of Helminthosporium and Nigrospora, but it did not control the occurrence of Cladosposrium and caused the occurrence of Penicillium in large intensity. The occurrence of Epicoccum, Curvularia, Phitomyces and Aspergillus genus were totally controlled by the treatment of hay with 1% of NH3; .9 and 1.8% of urea.

Efeitos da amonização sobre o valor nutritivo do feno de capim-braquiária

This work was conducted to determine the effects of ammoniation and supplementation on the nutritive value of signal grass (Brachiaria decumbens Stapf) hay. The hay was treated with anhydrous ammonia (3.0% DM) and introduced into the rations for sheep with 12.00% of CP, identified as T1 grass hay without NH3 + cotton seed meal; T2 = treated hay (3.0% de NH3); T3 = treated hay (3.0% de NH3) + com grain meal; T4 = hay + cotton seed meal + corn grain meal. nit: following coefficients of digestibility were determined for T1, T2, T3 e T4, respectively: DM (54.90; 55.50); 54.50; and 56.12%); NI)I: (51.36; 60.20; 55.30; and 48.35%); ADF (47.36; 58.66; 56.03; and 47.07%); hemicellulose (58.80; 63.32; 56.00; and 49.70%); cellulose (55.58; 71.80; 68.07; and 58.21%); lignin (10.10; 32.18; 31.74; and 0.72%) and protein (64.6; 59.36; 56.16; and 70. 15%). nle N balances for T1, T2, T3 and T4 were 5.69; 3.88; 3.90; and 8,82 g N/day. It was concluded that the ammoniation was equivalent to the vegetable protein supplementation in the rations. Furthermore, this treatment showed a greater potential to increase fiber digestion, particulary for ADF and cellulose.

STUDY OF AMNONIFYING BACTERIA BEHAVIOR IN THE LAKES CARIOCA AND D-HELVECIO (RIO-DOCE-VALLEY-MG)

The study of the amnonifying bacteria behavior in the lakes Carioca and D. Helvecio, which belong to the natural lacustrine system of the Rio Doce Valley - Minas Gerais - Brazil, during the period from March to November, showed a similar seasonal variation in both lakes, with higher population density in March and November (raining period) and lower density in May, July and September (dry period). The vertical variation was also relatively similar for both lakes, were during the thermal stratification the distribution was regular along the water column, while during the period of thermal stratification the populational density was remarkably different at different depths. The characterized ammonifying types to the genera Acinetobacter, Moraxella and Proteus, which in culture reveal high amnonifying activity with values which have reached 30,8 mug/l of ammonia per population unity (105 bacteria/ml).

Effect of ammoniation and moisture-content on the quality of signal grass (Brachiaria-decumbens stapf) hay

The experiment was carried out to evaluate the effects of two moisture levels (18-20% and 13-15%) and three anhydrous ammonia levels (0.0; 1.5; 3.0% of NH3) on the quality of Brachiaria decumbens Stapf hay. The hay was bailed in April and weighed and treated under plastic cover during 30 days. The hay presented a similar chemical composition when bailed with high or low moisture. The percentages of NDF (80.59; 77.61; 76.10%); hemicellulose (32.56; 29.48; 28.76%) and lignin (9.53; 8.21; 7.54% decreased and the percentages of crude protein (4.04; 11.35; 13.22%) and IVDMD (36.78; 49.72; 54.33%) increased as the NH3 level increased. The fractions ADF, cellulose, and ADIN did not change due to the ammoniation. The incidence of fungi decreased with application of NH3 being the better results obtained with the 1.5% treatments.

Prediction via neural networks of the residual hydrogen peroxide used in photo-fenton processes for effluent treatment

This communication proposes the use of neural networks in the prediction of residual concentrations of hydrogen peroxide from the treatment of effluents through Advanced Oxidative Processes (AOP's), in particular, the photo-Fenton process. To verify the efficiency of the oxidative process, the Chemical Oxygen Demand (COD) parameter, the values of which may be modified by the presence of oxidizing agents such as residual hydrogen peroxide, is frequently taken in account. The analysis of the H2O2 interference was performed by spectrophotometry at 450 nm wavelength, via the monitoring of the reaction of ammonia with metavanadate. The results of the hydrogen peroxide residual concentration were modeled via a feedforward neural network, with the correlation coefficients between actual and predicted values above 0.96, indicating good prediction capacity.