[en] Measurements of the content of nitrogen oxides and 16 polyaromatic hydrocarbons (PAH), including napthaline, in flue gas from four natural-gas fired process burners with low emission of nitrogen oxides are presented in addition to measurements of the content of oxygen and carbon dioxide. PAH2 emission was highest at high temperatures and an input effect where the proportion of primary air was low. NO_x emission was dependent on the variation of the proportion of primary air, flue gas temperature and input effect. NO_X emission was highest where the input effect was low, and lowest where the proportion of primary air was low and input effect and flue gas temperature were high. It was possible to adjust the burners so that NO₂ emission was reasonably low without PAH2 emission becoming high. It was concluded that the extent of carbon monoxide emission can be used to indicate that of PAH2. Several gas burners of varying design and combustion principles were evaluated with regard to emission of NO_x and PAH. Fiber burners gave low emission except in the case of PAH2 which was the same as for the other burners. Carbon monoxide emission was higher in the case of duct burners, but in this case it did not mean that PAH2 emission was higher. (AB)

[en] An important first step in the initiation of carcinogenesis by polycyclic aromatic hydrocarbons (PAH), is the formation of a covalently bound adduct between the metabolized PAH and one or more deoxyribonucleic acid bases. In vivo concentrations of these adducts are typically ∼1 adducted base per 10⁸ normal DNA base pairs. In this paper methods of generating high resolution fluorescence spectra of adducts at these levels are described. Methods of overcoming factors such as photochemistry and nonphotochemical hole burning which limit detection limits are described. By generating line narrowed fluorescence spectra, it is possible to spectrally distinguish between various adduct possibilities

[en] The various parameters determining the reactions of PAH in the particulate phase are studied. An alternating pulsed-flow reactor allowing continuous mixing of the particles and evacuation of the reactant gases, has been constructed. A preliminary study of the photolysis of particulate PAH by sunlight and in the absence of oxidizing gases shows that photolysis is negligible for short irradiation times (< 2h) for most of the 6 PAH studied: anthracene, fluoranthene, pyrene, benzo(a)pyrene, benzo(ghi)perylene and benzo(b)fluoranthene, and for the two substrates used: alumina and fly ash. On the other hand, this study shows that the particle surface is deactivated and that the PAH-support bonds are weakened; there is partial desorption of PAHs under photonic impact. Two types of PAH are present in the particulate phase: reversibly physisorbed and irreversibly chemisorbed PAH. This phenomenon has not been considered in kinetic studies. It may even cast some doubt upon the determination of atmospheric concentrations which are probably underestimated by classical analytical methods

[en] A study was conducted to examine some of the factors necessary to assess the environmental impact of an in-situ burn of an oil spill on water. These factors include the fraction of an oil layer which can be burned, the quantity of smoke emitted, and the concentrations of 18 polycyclic aromatic hydrocarbons (PAHs) in the smoke, crude oil, and burn residue. Alberta sweet mixed blend crude in 1, 3, 5, 10, and 30 mm layers on water was burned in the laboratory and smoke samples were collected at elevated and ambient temperatures and analyzed by two independent laboratories. While burning the crude oil produced less total PAHs than was in the original crude, the concentrations of PAHs with 5 or more rings were 10-20 times greater in the smoke than in the oil. The organic carbon fraction of the smoke was in the 14-21% range. As the fuel layer thickness was increased from 2 to 10 mm, the smoke yield increased from 0.035 g smoke/g fuel and the percentage of oil residue decreased from 46% to 17%. By consuming much of the oil spill and reducing the amount of PAHs in the water, and by dispersing the combustion products over a larger area, in-situ burning can mitigate the local environmental impact of an oil spill. There appears to be a range of situations, such as in Arctic ice fields, where in-situ burning might be the most viable cleanup method. 25 refs., 6 figs., 6 tabs

[en] Ecology of Estuaries: Anthropogenic Effects represents the most definitive and comprehensive source of reference information available on the human impact on estuarine ecosystems. The book discusses both acute and insidious pollution problems plaguing these coastal ecotones. It also provides a detailed examination of the deleterious and pervasive effects of human activities on biotic communities and sensitive habitat areas in estuaries. Specific areas covered include organic loading, oil pollution, polynuclear aromatic hydrocarbons, chlorinated hydrocarbons, heavy metals, dredging and dredge-spoil disposal, radionuclides, as well as other contaminants and processes. The diverse components of these anthropogenic influences are assembled in an organized framework and presented in a clear and concise style that will facilitate their understanding

[en] Short communication

[en] This paper discusses biodegradation, a technically viable and cost effective approach for the reduction and immobilization of polynuclear aromatic hydrocarbons (PAH) present in contaminated soils and sludges associated with coal-tar derived processes. While it is widely reported and accepted that PAH biodegradation in soil systems does occur, the specific controlling mechanisms are not entirely understood. One common observation among published reports is that the more soluble, lower molecular weight PAH compounds are biodegraded to a greater extent than the less soluble, higher molecular weight PAHs. The rate and extent to which PAHs are removed form soil/sludges is influenced by the combined and simultaneously occurring effects of volatilization, sorption and biological oxidation. The degree to which each of these three environmental fate mechanisms occurs is mainly influenced by the physical/chemical characteristics of the contaminated media, the physical/chemical characteristics of the specific PAH compounds, and the design and operation of the particular biological treatment process

[en] Extraction of organic compounds from soils is most commonly done using time-consuming laboratory procedures. Rapid, portable methods for measuring the concentrations of semivolatile organic compounds in the field are needed. This report describes the development of a supercritical fluid extraction (SFE) method using field-portable equipment that completes the extraction in less than 30 minutes and permits on-site quantification of such compounds in soil samples. 10 figs., 34 tabs., 21 refs

[en] In this paper we describe HPLC procedures for the quantitative analysis of a range of pollutants in various matrices: The analysis of polynuclear aromatic hydrocarbons. The stationary phase of the analytical column was developed in our lab to meet the desired selectivity and reproducibility. Method for screening surface - and drinking water for pesticides and pesticide residues, combining off-line preconcentration with gradient reversed phase HPLC. Analysis is done on an HPLC column, tailor made for pesticide analysis. By the use of the preconcentration step, a 10 fold increase in sensitivity is achieved, resulting in detection limits of sub ppb for substances like: urea pesticides, chlorophenoxyacids, nitro- and chlorophenols. Analysis of volatile ketones and aldehydes in air. The method integrates sampling with off-line precolumn derivatization (with 2,4 dintrophenylhydrazine). The trapped DNPH-derivatives are extracted and analyzed using standard gradient RPLC. Limits of detection are the ppb level

[en] Slow pumping is a well evacuation and sampling technique intended to facilitate the influx of ambient water. By pumping at a rate that does not greatly exceed theoretical well screen flow-through, unnatural sediment and non-aqueous phase liquid shearing is minimized to the extent practical. The technique would theoretically lead to a true sample for development of more accurate concepts of total transport, including the dissolved phase and facilitated transport phases. The study site is a 70-acre former manufactured gas plant (MGP). Many wells on the study site are screened in materials containing MGP tar. Historic ground-water analyses have shown polycyclic aromatic hydrocarbon (PAH) concentrations in excess of their solubilities. The anomalous PAH concentrations could have been caused by increased turbidity or emulsified MGP tar induced during traditional aggressive purging. To better characterize actual PAH transport, the slow pumping technique has been adopted. Procedures have been modeled after those developed by the Massachusetts Institute of Technology (MIT). Three phases of slow pumping site application were planned: site specific confirmation, technique development, and a full site-wide sampling event. Site-specific confirmatory tests indicate results similar to MIT'S. Samples from wells screened in residual MGP tar show considerably lower PAH concentrations, particularly for the heavier molecular weight compounds, than previous samples obtained by traditional methods. Study results allude to the hypothesis that the application of slow pumping at the subject study site minimizes, to the extent practical, sampling biases associated with traditional purging and sampling