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PubMed2002

A study of fine particulate emissions from combustion of treated pulverized municipal sewage sludge.

Municipal sewage sludge (MSS) is formed during wastewater treatment and its processing and disposal represent one of the most environmentally challenging aspects of the wastewater treating process. One disposal option currently being considered is a process involving heat treatment (to render the sludge biologically inactive) followed by dewatering, drying, pulverizing, and combustion. This research focuses on fine particle emissions from the combustion of dried, treated, MSS, cofired with either natural gas or pulverized Ohio bituminous coal as a supplemental fuel. These fuels were burned at 13 kW in a downflow laboratory combustor designed to replicate time/temperature histories and particle concentrations typical of practical combustion units yet also sufficiently well defined aerodynamically to allow elucidation of mechanisms. Size-segregated particle size distributions were obtained by isokinetic sampling followed by dilution/quenching and passage into a Berner Low-Pressure Impactor. Major and trace elements were analyzed by flame and graphite furnace atomic absorption spectroscopy. Four particle size regions were identified: furnace vapor-phase material that formed ultrafine particles either in or just before the sampling probe, submicron-sized particles formed during the combustion process, micron-sized fine particles, and larger supermicron sized bulk fly ash particles. The fuel mix appears to influence trace metal partitioning routes and the composition of fine particulate matter in the exhaust. Cofiring of MSS with coal increases the ultrafine/submicron particle emission compared to firing coal alone. This increase in ultrafine/submicron particles is most likely due to an interaction between species derived from MSS (possibly alkali metals) and those from coal (possibly sulfur and/or chlorine). Vapor-to-solid phase partitioning of arsenic and selenium is controlled by surface reaction with active surface sites during MSS combustion with either gas or coal. Co-combustion of MSS with the Ohio bituminous coal allows the arsenic and selenium to be reactively scavenged by calcium, thus changing the speciation of the trace metal emitted. Ohio bituminous coal alone contained insufficient calcium to accomplish this same scavenging effect.

Air Pollutants↗
PubMed1972

Laboratory mill for pulverizing and homogenizing nail specimens as an aid to microscopy and culture confirmation of onychomycosis.

A small mill has been developed for reducing nail clippings to a convenient size for microscopy and inoculation onto isolation media. The milling process acts to pulverize and homogenize the specimen. The use of a homogeneous sample in microscopy increases the opportunity for the discovery of fungal hyphae in a specimen. The use of a pulverized specimen increases the possibility of culture isolation by permitting greater numbers of potentially viable fungal cells to come into direct contact with the isolation medium.

Candida albicans↗
PubMed1976

Effect of pulverized implantation materials (plastic and glass ceramic) on growth and metabolism of mammalian cell cultures.

The effect of pulverized plastic and glass-ceramic materials (methylmetacrylate, MNA), which are used as implantation materials in surgical medicine, on cell growth, DNA synthesis rate (adjudged by incorporation of 3H-thymidine into DNA), glucose consumption and lactate production (glycolytic rate) was studied in asynchronous monolayer cultures of rather fast proliferating Ehrlich ascites tumor cells and rather slowly proliferating diploid human fibroblasts. Exposure of Ehrlich ascites cells to high concentrations (2 mg/ml; 10 ml medium per culture) of ceramic or plastic material resulted in a gradual inhibition of cell growth and DNA synthesis rate. Protein synthesis, as measured by the incorporation of 3H-leucine, was somewhat less affected than DNA synthesis. Also, the glycolytic rate of Ehrlich ascites cells was slightly but significantly decreased in the presence of 2 mg/ml ceramics or MMA. Exposure of Ehrlich ascites cells to 0.2 or 0.02 mg/ml over a period of 46 h revealed none or only slight inhibitory effects on growth, DNA synthesis or glycolytic rate. On the other side, growth, DNA synthesis and glycolytic rates of human fibroblasts were nearly not affected by the presence of the same concentrations (up to 2 mg/ml, incubation period: 92 h) of pulverized ceramic or plastic material (MMA). It is suggested that this differential cellular sensitivity might be related to differences in the binding (to the cell surface) or uptake of these substances and possibly to differential intracellular lysosomal activation.

Animals↗
PubMed2004

Treatment of gastric hemorrhage by pulverized omeprazole and antacid--concomitant administration via a nasogastric tube.

Gastroesophageal reflux (GER) is a common episode in pediatric patients with severe motor and intellectual disabilities (SMID) and occasionally leads to a severe clinical state accompanied with nausea, hematemesis, melena, wheezing, pneumonia, anemia and/or failure to thrive. We report here a case of a 14-year-old male with Lennox syndrome who had been treated with a histamine H2 blocker intravenously or via a nasogastric tube for repeated gastric hemorrhage due to severe GER. Since his gastric hemorrhage became resistant to the H2 blocker, we decided to replace it with a proton pump inhibitor (PPI). Although lansoprazole can be decapsulated for administration via a nasogastric tube, it tends to block fine tubes. The acid-sensitive drug omeprazole, another oral PPI, is commercially available as enteric-coated tablets. Therefore, we pulverized the tablets and administered omeprazole, mixed with a small amount of antacid, via a nasogastric tube. The patient's gastric hemorrhage was dramatically improved. Thus, administration of pulverized omeprazole concomitantly with antacid via a fine nasogastric tube may provide a novel approach for the treatment of chronic GER in pediatric patients with SMID.

Adolescent↗
PubMed2006

[Effect of tongxinluo ultramicro-pulverization on myocardial post-reperfusion no-reflow in mini-swine model of acute myocardial infarction].

OBJECTIVE: To assess the effect of Tongxinluo (TXL) ultramicro-pulverization in preventing and treating post-reperfusion no-reflow in mini-swine model of acute myocardial infarction. METHODS: Forty mini-swines were randomly divided into 5 groups, the control group, the three (low-, middle- and high-dose) TXL groups and the sham-operation group, with 8 in each group. After pigs in the three TXL groups were administered with TXL in a dose of 0.05g/kg, 0.2g/kg and 0.5g/kg once a day for 3 days respectively, they were made into acute myocardial ischemia/reperfusion model by ligating left anterior descending coronary artery for 3h followed with 1h of untying. Hemodynamic examination and myocardial contrast echocardiography (MCE) were conducted before and after ligation, and after reperfusion, finally, pathological analysis was done. RESULTS: Post-reperfusion ventricular function injury was significantly improved in the three TXL groups, as compared with the control group, the no-reflow area determined by hemodynamic and MCE decreased from 78.5 +/- 4.4% and 82.3 +/- 1.9% in control to 43.4 +/- 3.2% and 44.6 +/- 3.3% (low-dose), 25.2 +/- 2.4% and 25.7 +/- 4.0% (middle-dose), 24.0 +/- 1.9% and 24.9 +/- 4.2% (high-dose), respectively (P < 0.05 or P < 0.01), and the myocardial infracted area was reduced from 98.5 +/- 1.4% to 89.8 +/- 4.6%, 80.2 +/- 3.1% and 79.9 +/- 3.1%, respectively (P < 0.05, P < 0.01). CONCLUSION: TXL ultramicro-pulverization can effectively prevent and treat no-reflow after myocardial acute infarction following reperfusion, and reduce the infracted area.

Animals↗
PubMed1979

Degradation of bone matrix morphogenetic activity by pulverization.

The yield of new bone from implants of pulverized demineralized whole matrix and bone matrix gelatin declines as the particle size decreases in diameter below 125 microns. The corresponding increase in surface area and mechanically-induced free radicals is associated with an increase in solubility of bone matrix proteins. These changes in physiocochemical properties and the concomitant reduction in bone yield suggest that prolonged pulverization denatures a bone morphogenetic protein (BMP).

Animals↗
PubMed1993

Bound lipids liberated by alkaline hydrolysis after exhaustive extraction of pulverized clavus.

In the present study, covalently bound lipids were found in clavus material and their lipid classes were determined by high-performance thin-layer chromatography (HPTLC). Clavus material, pulverized completely in a Mikro-Dismembrator II, was exhaustively extracted three times with chloroform/methanol (2:1, 1:1 and 1:2 v/v) at 80 degrees C for 1 h each time and this sequence of extractions was repeated to obtain the unbound lipid-free residue which was saponified and then extracted with chloroform. The extract proved to comprise several bands of lipids covalently bound through an ester-like linkage. These were identified as free fatty acids, cholesterol, ceramides and glucocerebrosides by HPTLC. However, omega-hydroxy fatty acids were not detected in the lipids. To analyse the fatty acids amide-linked to the bound ceramides, the latter were isolated by preparative HPTLC and subjected to mild acid hydrolysis. Since the bound ceramides constituted neither omega-hydroxy fatty acids nor alpha-hydroxy fatty acids, they were not identified as hydroxyl-acylsphingosines.

Chromatography, Thin Layer↗
PubMed2005

Dust explosion hazard of pulverized fuel carry-over.

This paper reports the results of experiments done to examine the explosibility of the waste products (fly ash and bottom ash) from pulverized fuels (coal and petroleum coke). Tests were conducted for the fly and bottom ashes alone and also for selected fly ashes blended with the fuels. The explosion parameters of interest were explosion pressure and rate of pressure rise. The fly ashes showed no propensity to explode, whereas one of the bottom ashes did show limited explosibility. Both findings can be explained with reference to the volatile matter content of the ashes. Admixture of either coal or petroleum coke with fly ash resulted in explosible mixtures at volatile contents in the range of 7-13%, with the value being dependent on the composition of the mixture components and their particle sizes.

Carbon↗
PubMed2006

Assessing arsenic leachability from pulverized cement concrete produced from arsenic-laden solid CalSiCo-sludge.

Synthetically prepared arsenic-laden CalSiCo-sludge was converted to pulverized cement concrete (PCC) using solidification/stabilization technology with cement. Batch leaching experiments were conducted to estimate the leaching of As(III) and As(V) from the CalSiCo-sludge as well as from the PCC. The leaching of As(III) and As(V) was found to be the function of time, pH and concentration of anions such as Cl(-), NO(3)(-), and SO(4)(2-) present in the extraction fluid. It is observed that from the CalSiCo-sludge the leaching of As(III) is >0.05mg/l (which is above the permissible limit for arsenic in drinking water) at any pH. But in case of As(V) the leaching is >0.05mg/l only at pH>8 and at pH<4. It is noted that maximum leaching occurs when the extraction liquid contains Cl(-). In contrary, NO(3)(-) and SO(4)(2-) have negligible effect on arsenic leaching from the CalSiCo-sludge. Extraction tests were carried out to determine the maximum leachable concentration under the chosen conditions of leaching medium and leaching time. Leaching of As(III) and As(V) from exhausted arsenic-laden CalSiCo-sludge and from PCC was carried out in both tap water and rain water. It was noticed that tap water has no effect in leaching of arsenic from CalSiCo-sludge but rain water causes significant amount of leaching, which is mostly due to pH effect. However, in all cases the leaching of As(III) was more than that of As(V). When compared with CalSiCo-sludge PCC showed negligible leaching of arsenic. It was noticed further that the variation of 28 days compressive strength was within 15% of the original strength after replacing 35% cement with exhausted CalSiCo-sludge.

Adsorption↗
PubMed2000

Partitioning behavior of trace elements during pilot-scale combustion of pulverized coal and coal-water slurry fuel

Release pathways for inorganic hazardous air pollutants (IHAPs) from a pilot-scale, down-fired combustor (DFC) when firing pulverized coal (PC) and coal-water slurry fuel (CWSF) were identified and quantified to demonstrate the effect of fuel form on IHAP partitioning, enrichment and emissions. The baghouse capturing efficiency for each element was calculated to determine the effectiveness of IHAP emission control. Most of the IHAPs were enriched in the fly ash and depleted in the bottom ash. Mercury was found to be enriched in the flue gas, and preferentially emitted in the vapor phase. When firing CWSF, more IHAPs were partitioned in the bottom ash than when firing PC. Significant reduction of Hg emissions during CWSF combustion was also observed.

Journal Article↗
PubMed2000

An investigation on polycyclic aromatic hydrocarbon emissions from pulverized coal combustion systems

Results from a series of tests conducted to study the emission of polynuclear or polycyclic aromatic hydrocarbons (PAHs) from bench-scale and small industrial, water-tube boiler are discussed. A Middle Kittanning, and Upper Freeport seam coals were used in the study. Samples were extracted from the reactor outlet and from the inlet and outlet sides of the research boiler's (RB) baghouse using EPA promulgated methods.Only acenaphthene and fluoranthene were detected in down-fired combustor (DFC) samples. In addition to these two, naphthalene was detected in the RB samples. Emission factors ranged from 80 to 320 &mgr;g/kg of fuel fired. Although there were minor trends in the emissions' data, given the reproducibility limits for PAH compounds, no significant differences were found in the emissions with respect to the fuel type or form (pulverized coal (PC) vs. coal-water slurry fuel (CWSF), and raw vs. cleaned coal) and firing conditions (high and low excess air). The PAH emissions showed a decrease with increase in the firing rate.A bench-scale drop-tube reactor (DTR) was used to study the effects of temperature and residence time on PAH formation. The results revealed near constant PAH concentrations in the solid-phase samples, while the PAH concentrations in the vapor-phase samples increased as a function of temperature. At a temperature of around 1300 degrees C, the rate of PAH formation was exceeded by the rate of PAH oxidation, and PAH concentrations in the vapor phase began to decrease.

Journal Article↗
PubMed2001

Trace elements in two pulverized coal-fired power stations.

Beside major pollutants (particulates, carbon, sulfur, and nitrogen oxides), coal combustion generates emissions of potentially toxic trace elements. The current work focuses on predicting the fate of eight trace elements (As, Cd, Hg, Ni, Pb, Se, V, and Zn) in power stations that fire pulverized coal and are equipped with flue gas scrubbers. The core of the study is global equilibrium analysis carried out with the aid of three extensive databases. The first set of equilibrium constants describes conditions prevailing in the furnace and the flue gas duct, while the second set describes reactions in the flue gas scrubber. Melting behavior of ash and solubility of trace elements within the slag are described as a third set of data. To test the modeling approach taken in this paper, the predicted overall partitioning of trace elements is compared with measured data from two full-scale facilities. The results of the study indicate that As, Cd, Ni, Pb, V, and Zn are captured in the fly ash, and that the fate of these element correlates with the overall particle capture of the power plants. Calculations for the flue gas scrubber facilities show that nonvolatile trace elements are likely to dissolve in the scrubber solution, and that capture of these elements likewise is correlated with the overall particulate behavior. Theoretical predictions of the melting behavior indicate that As, Ni, Zn, and to some extent Pb are likely to dissolve in the molten ash.

Air Pollutants↗
PubMed1998

Behavior of amino acids when volatilized in the presence of silica gel and pulverized basaltic lava.

To evaluate the types of amino acid thermal transformations caused by silicate materials, we studied the volatilization products of Aib, L-Ala, L-Val and L-Leu under temperatures of up to 270 degrees C in the presence of silica gel as a model catalyst and pulverized basaltic lava samples. It was found that silica gel catalyzes nearly quantitative condensation of amino acids, where piperazinediones are the major products, whereas lava samples have much lower catalytic efficiency. In addition bicyclic and tricyclic amidines and several products of their subsequent thermal decomposition have been identified using the coupled technique of GC-FTIR-MS and HPLC-PB-MS, with auxiliary computer simulation of IR spectra and NMR spectroscopy. The decomposition is due to dehydrogenation, elimination of the alkyl substituents and dehydration as well as cleavage of the bicyclic ring system. The imidazole ring appears to be more resistant to thermal decomposition as compared to the pyperazine moiety, giving rise to the formation of different substituted imidazolones. The amidines were found to hydrolyze under treatment with concentrated HCl, releasing the starting amino acids and thus behaving as amino acid anhydrides. The thermal transformations cause significant racemization of amino acid residues. Based on our observations, the formation of amidine-type products is suggested to be rather common in the high-temperature experiments on amino acid condensation.

Amidines↗
PubMed2004

Speciation and mass-balance of mercury from pulverized coal fired power plants burning western Canadian subbituminous coals.

This report summarizes the results of a study carried out on six pulverized coal-fired power plants in western Canada burning subbituminous coal for the mass-balance and speciation of mercury. The main objectives of this study were to: determine the total gaseous mercury (TGM) emitted from stacks of power plants using the Ontario Hydro method; identify the speciation of emitted mercury such as metallic (Hg(0)) and gaseous elemental (GEM) mercury; and perform mass-balance calculations of mercury for milled-coal, bottom ash, electrostatic precipitators (ESP) fly ash and stack-emitted mercury based on three tests. Sampling of mercury was carried out using the Ontario Hydro method and mercury was determined using the USEPA method 7473 by cold vapor atomic absorption (CVAAS). The sample collection efficiencies confirmed that both oxidized and the elemental mercury had been successfully sampled at all power plants. The total gaseous mercury emitted (TGM) is 6.95-15.66 g h(-1) and is mostly in gaseous elemental mercury (GEM, Hg(0)) form. The gaseous elemental mercury is emitted at a rate of 6.59-12.62 g h(-1). Reactive gaseous mercury (RGM, Hg(2+)) is emitted at a rate of 0.34-3.68 g h(-1). The rate of emission of particulate mercury (Hg(p)) is low and is in the range 0.005-0.076 g h(-1). The range of mass-balances for each power plant is more similar to the variability in measured mercury emissions, than to the coal and ash analyses or process data. The mass-balance calculations for the six power plants, performed on results of the three tests at each power plant, are between 86% and 123%, which is acceptable and within the range 70-130%. The variation in mass-balance of mercury for the six power plants is mostly related to the variability of coal feed rate.

Air Pollutants↗
PubMed1978

Induction of pulmonary carcinoma in rats by chronic inhalation of dust from pulverized asbestos pipe covering.

Rats and hamsters were exposed to the dust of pulverized asbestos pipe covering at an average concentration of 85 mg/m(3) for 6 h/d, 5 d/wk, for 7 mo, followed by a lifetime observation period. In rats, the pulmonary responses were alveolar adenomatous proliferation, nonprogressive fibrosis, squamous metaplasia, and a substantial incidence of pulmonary carcinoma formation. A smaller group of hamsters exposed under these conditions experienced an earlier onset of mortality than control hamsters, which were not subjected to the exposure regimen. Although this prevented conclusive evaluation of the pulmonary response in this species, no pulmonary neoplasms were noted in the surviving hamsters.

Animals↗
PubMed2006

Oral administration of pulverized Konjac glucomannan prevents the increase of plasma immunoglobulin E and immunoglobulin G levels induced by the injection of syngeneic keratinocyte extracts in BALB/c mice.

BACKGROUND: Immunoglobulin (Ig) E plays a key role in the pathogenesis of atopic diseases, such as asthma, atopic dermatitis and allergic rhinitis. Oral administration of pulverized Konjac glucomannan (PKGM) has recently been demonstrated to prevent both plasma IgE elevation and developing dermatitis in NC/Nga mice, a model of atopic dermatitis. OBJECTIVE: To clarify the direct effect of PKGM on the increase of plasma IgE, we employed the system of BALB/c mouse that increases IgE level without developing dermatitis in response to continuous injection of the extract of syngeneic keratinocytes, PAM 212 cells (PAM extract). METHODS: Three weeks after the start of feeding with either control or PKGM diet, mice were injected subcutaneously with PAM extract bi-weekly for 10 weeks. The levels of plasma Igs were measured by enzyme-linked immunosorbent assay every 2 weeks after the injection. The levels of epsilon germline transcription and the amounts of mRNA for IL-4, IFN-gamma, GATA-3 and T bet gene in the spleen were evaluated by real-time RT-PCR at the end of the experiment. RESULTS: On the one hand, PKGM prevented the increase of plasma IgE and IgG (IgG1, IgG2b) induced by PAM extract, and on the other hand, it enhanced the levels of plasma IgG3. However, it did not affect the level of plasma IgM. PKGM also reduced the levels of plasma ovalbumin (OVA)-specific IgE in OVA-sensitized mice. Moreover, PKGM attenuated the induction of epsilon germline transcription and expression levels of mRNA for IL-4, IFN-gamma and GATA-3 in the spleen of PAM extract-injected mice. PKGM also attenuated the induction of epsilon germline transcription and mRNA for IFN-gamma and T bet in the spleen of phosphate-buffered saline-injected control mice. CONCLUSIONS: These results suggested that oral administration of PKGM prevents the elevation of plasma IgE by suppressing IgE class switching in B cells and/or the commitment development of naive lymphocytes to both T-helper type 1 (Th1) and Th2.

Administration, Oral↗
PubMed1980

Pretreatment of exercise-induced asthma in adults with aerosols and pulverized tablets.

Eighteen adult asthmatics took part in a double-blind crossover study comparing the effect on exercise-induced asthma (EIA) of pretreatment with aerosolized 1) disodium cromoglycate (DSCG), 2) ipratropium bromide (IPTB), 3) fenoterol, 4) DSCG + IPTB and 5) saline. EIA was completely blocked by pretreatment with the beta 2-agonist, fenoterol. The protective effect of nebulized DSCG and IPTB given alone could not be distinguished from that of isotonic saline. The combination of DSCG and IPTB reduced the post-exercise bronchoconstriction more than any of the two drugs given separately. Thirteen of the 18 patients went on to a double-blind cross-over study of the effect on EIA of pretreatment with the usually recommended dosages off salbutamol, theophylline and their combination administered as pulverized tablets. Seven patients were withdrawn from this part of the study because of side-effects, and in the remaining six none of the oral pretreatments could be distinguished from placebo, despite serum theophylline concentrations within or above the commonly recommended therapeutical range.

Administration, Oral↗
PubMed2006

Experimental study on cement clinker co-generation in pulverized coal combustion boilers of power plants.

The idea to co-generate cement clinker in pulverized coal combustion (PCC) boilers of power plants is introduced and discussed. An experimental study and theoretical analysis showed this idea to be feasible and promising. By adding quick lime as well as other mineralizers to the coal and grinding the mixture before combustion, sulfoaluminate cement clinker with a high content of silicate (SCCHS) could be generated. The main mineral phases in SCCHS are 2CaO x SiO2 (dicalcium-silicate), 3CaO x 3Al2O3 x CaSO4 (calcium-sulfoaluminate) and 2CaO x A12O3 SiO2 (gehlenite). Performance tests showed that the SCCHS met the requirements for utilization in common construction. Based on this idea, zero solid waste generation from PCC would be realized. Furthermore, thermal power production and cement production could be combined, and this would have a significant effect on both environmental protection and natural resource saving.

Coal↗