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Coagulation of natural organic matter in groundwater using aluminium salts
1999
Karlovic, E. (Prirodno-matematicki fakultet, Novi Sad (Yugoslavia). Institut za hemiju) | Dalmacija, B. | Zejak, J. | Bajevic, Lj. | Djeric, J. | Djuric, Z.
Removal of natural organic matter (NOM) from groundwater by aluminium sulphate and polyaluminium chloride (PACl) was investigated. The maximal decrease of UV absorbance at 254 nm was near 70%. Decrease of permanganate value about 50% was achieved by PACl coagulation. Similar effect can be achieved using 2.5 fold higher concentration of aluminium sulphate. Coagulation process at pH 5.5 was successful with 3-5 times less concentration of coagulant. The heterogenous composition of NOM in water had been changing by coagulation. The total trihalomethane formation potential is 50-60% lower in coagulated water. The greatest removal was success for chloroform precursors.
Afficher plus [+] Moins [-]Removal of organic matter from water using activated carbon produced from domestic [Yugoslav] anthracite
1999
Tamas, Z. | Zejak, J. | Becelic, M. (Prirodno-matematicki fakultet, Novi Sad (Yugoslavia). Institut za hemiju)
Removal of natural organic matter from water was investigated using granulated activated carbon. Groundwater from northern Banat region (Serbia, Yugoslavia) was used. Samples of raw water and water after coagulation were ozonated and than GAC adsorption was performed. The investigation was carried out under the static conditions to determine the GAC adsorption capacity and kinetic coefficients.
Afficher plus [+] Moins [-]Chemical and spectroscopic analysis of organic matter transformations during composting of pig manure
1999
Hsu JennHung | Lo ShangLien (Graduate Institute of Environmental Engineering, National Taiwan University, 71 Chou-Shan Road, Taipei (Taiwan))
Fate of organochlorine pesticides in soils and terrestrial biota of Los Padres pond watershed, Argentina
1999
Miglioranza, K.S.B. | Aizpun de Moreno, J.E. | Moreno, V.J. | Osterrieth, M.L. | Escalante, A.H. (Laboratorio de Ecotoxicologia, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Funes 3350, 7600 Mar del Plata (Argentina))
A review of biomarker compounds as source indicators and tracers for air pollution
1999
Simoneit, Bernd R. T.
An overview of the application of organic geochemistry to the analysis of organic matter on aerosol particles is presented here. This organic matter is analyzed as solvent extractable bitumen/ lipids by gas chromatography-mass spectrometry. The organic geochemical approach assesses the origin, the environmental history and the nature of secondary products of organic matter by using the data derived from specific molecular analyses. Evaluations of production and fluxes, with cross-correlations can thus be made by the application of the same separation and analytical procedures to samples from point source emissions and the ambient atmosphere. This will be illustrated here with typical examples from the ambient atmosphere (aerosol particles) and from emissions of biomass burning (smoke).Organic matter in aerosols is derived from two major sources and is admixed depending on the geographic relief of the air shed. These sources are biogenic detritus (e.g., plant wax, microbes, etc.) and anthropogenic particle emissions (e.g., oils, soot, synthetics, etc.). Both biogenic detritus and some of the anthropogenic particle emissions contain organic materials which have unique and distinguishable compound distribution patterns (C₁₄-C₄₀). Microbial and vascular plant lipids are the dominant biogenic residues and petroleum hydrocarbons, with lesser amounts of the pyrogenic polynuclear aromatic hydrocarbons (PAH) and synthetics (e.g., chlorinated compounds), are the major anthropogenic residues.Biomass combustion is another important primary source of particles injected into the global atmosphere. It contributes many trace substances which are reactants in atmospheric chemistry and soot paniculate matter with adsorbed biomarker compounds, most of which are unknown chemical structures. The injection of natural product organic compounds into smoke occurs primarily by direct volatilization/steam stripping and by thermal alteration based on combustion temperature. Although the molecular composition of organic matter in smoke particles is highly variable, the molecular tracers are generally still source specific. Retene has been utilized as a tracer for conifer smoke in urban aerosols, but is not always detectable. Dehydroabietic acid is generally more concentrated in the atmosphere from the same emission sources. Degradation products from biopolymers (e.g., levoglucosan from cellulose) are also excellent tracers. An overview of the biomarker compositions of biomass smoke types is presented here. Defining additional tracers of thermally-altered and directly-emitted natural products in smoke aids the assessment of the organic matter type and input from biomass combustion to aerosols. The precursor to product approach of compound characterization by organic geochemistry can be applied successfully to provide tracers for studying the chemistry and dispersion of ambient aerosols and smoke plumes.
Afficher plus [+] Moins [-]Effect of litter quality and environmental factors on decomposition of organic matter in grass stands of deforested areas in the Beskids
1999
Tuma, I. (Akademie Ved, Ceske Budejovice (Czech Republic). Botanicky Ustav)