Polycyclic Aromatic Hydrocarbons (PAHs) are typical pollutants arising from incineration. They are produced in any incomplete combustion principally due to inhomogeneities in a combustion chamber. ...The effects of the afterburning temperature on PAHs formation during sewage sludge incineration are discussed in this paper. Tests were performed inside the area of the wastewater treatment plant of `Bari Ovest' on a demonstrative plant (maximum throughput 250 kg hr super(-1) of dewatered sludge at 20% solids concentration) equipped with a fluidised bed furnace (FBF) and a rotary kiln furnace (RKF) where sewage sludge was fed, either as it was taken from the dewatering section of the wastewater treatment plant, or previously spiked by different dosages of chlorinated hydrocarbons. Exhaust gases were sampled before the bag filter, where the pollutants can be considered representative of those arising from the process. Parallel sampling of flue gas at the stack was also carried out. In the FBF tests with sludge spiked with high dosages of chlorinated hydrocarbons highest values of PAHs concentrations (>3.9 kg Nm super(-3)) were detected before filtration, when the afterburning chamber was not in use. The operation of the afterburning chamber, at a temperature higher than 900 C, allows to partially suppress PAHs formation up to values of 0.9--3.2 kg Nm super(-3). PAHs removal efficiency of the exhaust gas treatment was calculated with a mean value for all the test of 72%.In RKF tests PAHs displayed much lower values before filtration (range 0.04--2.98 kg Nm super(-3), mean value 0.51 kg Nm super(-3)) probably due to the longer gas residence time in the furnace (>6 s in comparison with values <2 s in fluidised bed furnace). Surprisingly, for RKF tests PAHs removal efficiency of gas treatment appeared quite unstable: some tests evidenced PAHs stripping in the scrubber, where the effluent of the wastewater treatment plant was used. No correlation was observed in RKF tests between PAHs concentration before the bag filter and the temperature of the afterburning chamber.
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CEKLJ, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Due to the widespread use of atrazine, this herbicide and its degradation products (DPs) can contaminate waters destined for human consumption. The overall impact of these compounds in aquatic ...ecosystems has not yet been as sessed. This paper describes a very sensitive and specific method for ultratrace determination of atrazine and its six major DPs in environmental waters. This method is based upon solid-phase extraction with a new example of graphitized carbon black (Carbograph 4) followed by electrospray (ES) liquid chromatography−mass spectrometry (LC−MS). On extracting from 1 L of river water and 4 L of both groundwater and drinking water, analyte recoveries were better than 80%. Day-to-day precision was 2.9−9.8% at 25 ng/L (full-scan acquisition) and 2.3−7.7% at 3 ng/L (two-ion SIM acquisition). For all the analytes considered, raising the skimmer cone voltage in the desolvation chamber of the ES/MS system had the double effect of producing diagnostic fragment ions and enhancing the ion signal strength. In this way, highly specific full-scan LC−MS analysis of the seven analytes could be performed at levels down to 40−300 ng/L in river water samples. Time-scheduled selected ion monitoring of the intact molecular ion plus one related fragment ion could afford specific determination of the analytes at sub-nanogram per liter levels in groundwaters and drinking waters. A short survey conducted by analyzing some river (Tiber) water samples ascertained the presence of all the atrazine DPs, except DEDIA, at a few nanogram per liter levels.
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IJS, KILJ, NUK, PNG, UL, UM
In this note we describe the speciated particle‐phase PM2.5 polynuclear aromatic hydrocarbon (PAH) and gas‐phase carbonyl emissions as collected from a heavy‐duty diesel bus outfitted with an ...oxidation catalyst for exhaust after‐treatment. The vehicle was run on a chassis dynamometer during a transient cycle test reproducing a typical city bus route (Azienda Tramviaria Municipalizzata cycle). The diluted tailpipe emissions were sampled for PAH using a 2.5 μm cut size cyclone glass fiber filter assembly, while carbonyls were absorbed onto dinitrophenyl hydrazine‐coated silica cartridges. The former compounds were analysed by CGC‐MS, the latter by HPLC‐UV. Combining the two sets of speciation data resulting from 15 identical dynamometer tests provided a profile of both unregulated organic emissions. PAH emission rates decreased with the number of benzene fused rings. Fluoranthene and pyrene amounted to 90% of total PAHs quantified; six‐ring PAHs accounted only for 0.5%. Similarly, formaldehyde and acetaldehyde accounted for ˜ 80% of the total carbonyl emissions. Uncertainties of the method in the determination of individual emission factors were calculated. Statistical data processing revealed that all the measurements were quite unaffected by systematic errors and repeatability percentages did not exceed 50% for the majority of components of both groups.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
This article introduces the
Pickup and Delivery Problem under Track Contention, a particular vehicle routing problem in which loads have to be transported between origin–destination pairs by means of ...vehicles travelling along a capacitated network. Two sequential heuristics and a parallel tabu search are proposed. Computational experiments show that the parallel tabu search is able to find much better solutions than the sequential procedures, although this comes at the expense of a higher computing time.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The cytokines/related receptors system represents a complex regulatory network that is involved in those chronic inflammatory processes which lead to many diseases as cancers. We developed a Cytokine ...Receptor Database (CytReD) to collect information on cytokine receptors related to their biological activity, gene data, protein structures and diseases in which these and their ligands are implicated. This large set of information may be used by researchers as well as by physicians or clinicians to identify which cytokines, reported in the literature, are important in a given disease and, therefore, useful for purposes of diagnosis or prognostic.
The database is available for free at http://www.cro-m.eu/CytReD/
Introduction. The knowledge of chemical composition of the suspended particulate matter, first of all its fine (d <2 mu m) and inhalable (d <10 mu m, alias PM sub(10)) fractions, is mandatory to ...evaluate the influence on the atmospheric changes and the health impact on populated areas. Recently, the investigations focussing on the organic fraction of aerosols collected in urban, metropolitan and industrial areas have undergone large improvements. Our Institute carried out a 1-year long field campaign in Milan, in order to investigate the presence and behaviour of some of the most toxic micropollutants in aerosols, such as polycyclic aromatic hydrocarbons (PAH) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F). They are known to be emitted by coal combustion processes and industrial waste disposal, however, road traffic emission in urban areas has been identified as being a possible source. We investigated Nitrated PAH (NPAH) too, since they are expected to contribute up to 10% to the total mutagenicity of aerosols.
A comprehensive clean-up method for quantitative analysis of polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins and dibenzo-furans (PCDD/Fs) in one single extract of environmental ...samples was developed. Since the chemical nature and toxicity of planar PCBs are similar to those of PCDD/Fs, dioxin-like PCBs and PCDD/Fs are often surveyed together in their exposure assessments. The development of a method for the simultaneous analysis of PCBs and PCDD/Fs in environmental samples is invaluable. The automated clean-up system evaluated in this work consists of three additional steps after traditional extraction: the chromatography on gel permeation (GPC), the concentration of the solvent through the use of an in-line evaporation module and the further purification and separation of PCDDs/Fs and dl-PCBs on an alumina cartridge in the 'SPE module'. In this work, three fly ash samples from an interlaboratory study with different PCDD/F and PCB levels were Soxhlet-extracted and then cleaned up using an automated system. PCDD/Fs and PCBs were determined using isotope dilution and high resolution gas chromatography/high resolution mass spectrometry. The determined values of 17 PCDD/Fs were consistent with the certified values and the relative standard deviations (RSDs) of the determined values were less than 20%. The recoveries of (13)C labeled PCDD/Fs and planar PCBs, and their RSDs were within the ranges specified in EPA1613 and 1668a methods, respectively. An accurate and reliable method was successfully developed and can be used in the simultaneous analysis of PCDD/Fs and planar PCBs in environmental samples.
The authors describe their methods for streamlining the formulary at a small teaching hospital. The therapeutic drug review process comparatively examined pharmacology, pharmacokinetics, indications, ...side-effects, interactions, usage patterns, and costs within classes of medications. The information was presented in a table format which aided in the dissemination of large volumes of material and served as an educational tool for the medical and pharmacy staff. The goals of this program were avoidance of therapeutic duplication, assurance of efficacy, and cost containment without compromised patient outcome. The authors discuss methods for assuring intra-pharmacy and hospital wide cohesion in achieving the goals of formulary streamlining.
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