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951.
Analytical procedures for the determination of nine organic booster biocides which are currently licensed for use in marine antifouling paints, and are thought likely to occur at concentrations in the ng 1−1 range in estuarine water samples, are reviewed. A robust multiresidue method for the determination of four compounds (chlorothalonil, dichlofluanid, diuron and Irgarol 1051) is suggested. A route for the development of a method for the analysis of zinc pyrithione is outlined, based on an extraction method and subsequent derivatisation prior to determination by HPLC with fluorescence detection. Methodology for Zineb, Kathon 5287, TCMS pyridine and TCMTB is less clearly defined. 相似文献
952.
Dale L. Keyes Mark A. Scruggs Barry Kumar 《Journal of the Air & Waste Management Association (1995)》2013,63(6):671-673
The partition and effective diffusion coefficients of formaldehyde were measured for three materials (conventional gypsum wallboard, “green” gypsum wallboard, and “green” carpet) under three relative humidity (RH) conditions (20%, 50%, and 70% RH). The “green” materials contained recycled materials and were friendly to environment. A dynamic dual-chamber test method was used. Results showed that a higher relative humidity led to a larger effective diffusion coefficient for two kinds of wallboards and carpet. The carpet was also found to be very permeable resulting in an effective diffusion coefficient at the same order of magnitude with the formaldehyde diffusion coefficient in air. The partition coefficient (K ma) of formaldehyde in conventional wallboard was 1.52 times larger at 50% RH than at 20% RH, whereas it decreased slightly from 50% to 70% RH, presumably due to the combined effects of water solubility of formaldehyde and micro-pore blocking by condensed moisture at the high RH level. The partition coefficient of formaldehyde increased slightly with the increase of relative humidity in “green” wallboard and “green” carpet. At the same relative humidity level, the “green” wallboard had larger partition coefficient and effective diffusion coefficient than the conventional wallboard, presumably due to the micro-pore structure differences between the two materials. The data generated could be used to assess the sorption effects of formaldehyde on building materials and to evaluate its impact on the formaldehyde concentration in buildings.
Implications: Based on the results of this study, the sink effects of these commonly used materials (conventional and “green” gypsum wallboards, “green” carpet) on indoor formaldehyde concentration could be estimated. The effects of relative humidity on the diffusion and partition coefficients of formaldehyde were found to differ for materials and for different humidity levels, indicating the need for further investigation of the mechanisms through which humidity effects take place. 相似文献
953.
Mark V. Brady Mikael Skou Andersen Anna Andersson Emils Kilis Sanna-Riikka Saarela Martin Hvarregaard Thorse 《Ambio》2022,51(1):69
In this perspective article, we provide recommendations for strengthening the policy framework for protecting the Baltic Sea from agricultural nutrient pollution. The most striking weakness is the lax implementation of prescribed abatement measures, particularly concerning manure management, in most countries. Institutions of the EU should also be leveraged for achieving Baltic Sea Action Plan (BSAP) goals. In contrast to the Helsinki Convention, the European Union has economic, political and legal mandates to further implementation and compliance. Equally important is the need for strengthening of local institutions, particularly Water Boards and independent agricultural advisory services in the eastern Baltic Sea Region countries. There is also an urgent need for implementation of voluntary land-use measures where EU funding available to farmers is more broadly and effectively used by providing it on the basis of estimated abatement performance, which can be realized through modelling. The enormous potential for funding performance-based schemes, manure management infrastructure and advisory services through the EU’s Common Agricultural Policy are currently underutilized.Supplementary Informationhe online version contains supplementary material available at 10.1007/s13280-021-01573-3. 相似文献
954.
Ariamalar Selvakumar Michael Borst Mark Boner Phil Mallon 《Water environment research》2004,76(1):67-72
This research investigated the effects of extending the holding time of samples for microbial analysis beyond the standard of 24 hours for purposes such as watershed characterization. Experiments were conducted with both sanitary wastewater and stormwater samples. The refrigerated samples (4 degrees C) were held for up to 9 days before being analyzed for two pathogens (Pseudomonas aeruginosa and Staphylococcus aureus) and five indicator organisms (total coliform, fecal coliform, fecal streptococcus, enterococcus, and Escherichia coli) by membrane filtration. The concentrations (as colony-forming units per 100 mL) were normalized by log10(transformation and used in subsequent statistical analysis testing for significant differences. The results suggested that the concentrations of microorganisms in water samples analyzed on days 1 and 2 did not vary significantly in 8 of 13 analyses. The results of a field study concluded that the concentration of fecal coliform did not change significantly between 7 hours holding time and greater than 24 hours holding time for fecal coliform. 相似文献
955.
Laboratory batch experiments were performed to evaluate the effectiveness of nickel catalysts, nanoscale zerovalent iron (nZVI) doped with palladium, and microscale ZVI for treatment of tetrachloroethene, trichloroethene, and n-nitrosodimethylamine (NDMA) in soil-groundwater slurries. Results indicated that the presence of NDMA inhibited degradation of chlorinated solvents. Although both the nickel catalyst and nZVI were able to degrade NDMA in deionized water, neither of these metals was effective at degrading NDMA in the soil-groundwater system evaluated in this study. The effectiveness of the nickel catalyst and nZVI, with respect to treatment of the chlorinated solvents, also appeared to be highly dependent on the groundwater geochemical conditions. Overall results of this study suggest that the degradation mechanisms involving nickel catalysts and nZVI in natural soil/groundwater systems are not well-understood, and addition of metal catalysts to ZVI may not necessarily enhance observed degradation rates in natural systems. 相似文献
956.
957.
Mark??agarEmail author Gunilla?Svensson Michael?Tjernstr?m 《Environmental Fluid Mechanics》2005,5(4):357-372
A real meteorological situation characterized by strong spatial and temporal variability of the meteorological fields in a
coastal region of eastern Denmark is examined in view of the transport of a passive tracer and dry deposition. Model simulations
using a full mesoscale NWP model (COAMPSTM) at different horizontal resolutions are performed. A realistic simulation showed that the differences in the amount of dry
deposited matter can reach one order of magnitude and larger, during the period of one afternoon, depending on the model horizontal
resolution. In addition, the results of an idealized experiment with straight coastline indicate that the horizontal model
resolution alone is responsible for most of the differences. This study confirms the importance of high spatial and temporal
resolution modelling for environmental applications. 相似文献
958.
Simone Bagnis Mark F. Fitzsimons Jason Snape Alan Tappin Sean Comber 《Environmental Chemistry Letters》2018,16(4):1193-1216
The global consumption and production of pharmaceuticals is increasing concomitantly with concern regarding their environmental fate and effects. Active pharmaceutical ingredients are mainly released into the aquatic environment through wastewater effluent discharge. Once in the environment, pharmaceuticals can undergo processes of natural attenuation, i.e. dilution, sorption, transformation, depending on physico-chemical properties of the compound, such as water solubility, lipophilicity, vapour pressure, and environmental conditions, such as pH, temperature and ionic strength. A major natural attenuation process is the sorption on dissolved organic matter, colloids, suspended solids and sediments, which in turn control pharmaceuticals distribution, residence time and persistence in aquatic systems. Here we review studies of sorption capacity of natural sorbents to pharmaceuticals. These report on the importance of several environmental and sorbent-specific properties, such as the composition, quality, and amount of the sorbent, and the environmental pH, which determines the speciation of both the sorbent and compound. The importance of accounting for distribution processes on freshwater sorbents for any determination of environmental concentrations of pharmaceuticals is apparent, while the reliability of surrogate standards for measuring dissolved organic matter (DOM) distribution is evaluated in the context of the need for robust environmental risk assessment protocols. 相似文献
959.
Robert W. Russell F. Lynn Carpenter Mark A. Hixon David C. Paton 《Conservation biology》1994,8(2):483-490
We examined the impact of variation in habitat quality on migrating Rufous Hummingbirds ( Selasphorus rufus ) in the California Sierra Nevada. As do other migratory species, these birds depend on "stopover" habitats en route for feeding and replenishing depleted energy stores. During seven years of study, the quality of the stopover habitat (assessed in terms of the density of nectar food resources) varied widely due to natural variation in flowering. In years when stopover habitat quality was poor, incoming body masses were low and stopover durations were long. Population densities of migrant hummingbirds at the study site were coupled to habitat quality both within and among years. These observations demonstrate important effects of stopover habitat variation on the physiological, behavioral, and population ecology of migrating hummingbirds. High-quality stopover habitats are critical links between breeding and wintering areas for many species, and their preservation should be considered an essential component of strategies aiming to conserve migratory bird populations. 相似文献
960.