خيارات البحث
النتائج 141 - 150 من 240
[Towards management of the aquatic environment]
1994
Calamari, D. | Naeve, H.
(Effects of air pollution on forest ecosystems - a system-analytical attempt from the view of ecological genetics)
1994
Degen, B. | Scholz, F.
Pollution of soils and watercourses by wastes from livestock production systems
1994
Webb, J. | Archer, J.R. (ADAS, Nobel House, 17 Smith Square, London SW1P 3JR (United Kingdom))
Engineering risk analysis of water pollution
1994
Ganoulis, J.
Toxic properties of pesticides
1994
Cheremisinoff, Nicholas P. | King, John Allison
This unique resource offers concise, detailed information on the toxicological properties of and safe handling practices for pesticides and provides an overview of the registration process, registration procedures, and supplemental registration. Explaining the interaction between federal and state authorities on toxic chemicals, Toxic Properties of Pesticides gives an alphabetic listing of over 800 chemicals including their applications - from insecticides and growth regulators to herbicides, repellents, and synergists ... examines cancellation and suspension regulations ... furnishes safety guidelines and emergency treatment procedures ... elucidates the signs and symptoms of poisoning ... organizes chemicals according to product name, properties, toxicity, and uses ... supplies a listing of pesticide manufacturers and their addresses ... synthesizes previously uncollected data ... and more.
اظهر المزيد [+] اقل [-]Groundwater contamination and control | Ground water contamination and control
1994
Tsoler, Uri
This comprehensive, interdisciplinary reference explains the basic physical, hydrological, chemical, and biochemical processes and mechanisms governing contaminants in the subsurface vadose zone - an often overlooked problem that is of major worldwide societal concern. Additionally, this important resource provides helpful case studies representing state-of-the-art techniques and contains never-before-published research findings on, and recommendations for solving, groundwater contamination. | Covering a wide spectrum of groundwater contamination sources and their chemical, transport, and release characteristics, Groundwater Contamination and Control considers the preventive as well as corrective approaches in combatting the threat of irreversible groundwater pollution ... explores the challenges faced in remediating and rehabilitating polluted soils and aquifers ... analyzes the legislative aspects that arise when monitoring landfills, spills, and industrial sites ... reviews the U.S. Environmental Protection Agency's Groundwater Disinfection Rule ... describes the in situ process of on-site remediation ... discusses the political and legal issues involved in cases where aquifers are shared between people or countries ... previews future trends in on-site analysis and monitoring methods ... and much more. | Illustrated with nearly 450 figures, tables, and equations and containing more than 1700 literature citations to facilitate further in-depth study, Groundwater Contamination and Control is essential reading for pollution control, environmental, chemical, industrial, sanitary, and civil engineers; chemists; hydrologists; ecologists; agronomists; environmental scientists; waste management consultants; environmental regulators and government policymakers; and upper-level undergraduate and graduate students in these disciplines.
اظهر المزيد [+] اقل [-]Deposition of semivolatile organic compounds to spruce needles. 1. Calculation of dry and wet fluxes
1994
Umlauf, G. (Bayreuth Univ. (Germany). Lehrstuhl fuer Oekologische Chemie und Geochemie) | McLachlan, M.
The deposition of atmospheric tetrachlorobenzene, pentachlorobenzene, hexachlorobenzene, alpha-HCH, gamma-HCH, DDT, DDE and the PCB congeners 52, 101, 138, 153 and 180 to spruce needles (Picea abies) was estimated for a period of 9 months. Accumulation in spruce as a result of dry gaseous deposition, particle bound deposition and wet deposition was calculated on the basis of the corresponding deposition rates and the compounds' concentrations in the different atmospheric compartments. The comparison of the calculated values with the concentrations of the compounds measured in 9-month-old spruce needles showed that for many compounds each deposition pathway could explain a large part of the concentrations found in the needles.
اظهر المزيد [+] اقل [-]Ancient atmosphere - Validity of ice records
1994
Jaworowski, Z. (Institutt for Energiteknikk, Kjeller (Norway))
Interpretation of the greenhouse data from the ice cores are sometimes based on rejection of analytical results, and often on assumptions disregarding gas fractionation processes. At present, our understanding of these processes in ice sheets is rather poor. There is a need for experimental studies which would provide the essential physical and chemical parameters needed. Before such studies are carried out, conclusions on low pre-industrial atmospheric levels of greenhouse gases cannot be accepted when deduced from ice core data. High contamination of the inner parts of the ice cores with lead and other metals by the drilling procedure is compelling evidence that the cores do not fulfil the absolutely essential, closed system criterion. Thus, they are not suitable for reconstruction of the composition of pre-industrial and ancient atmosphere.
اظهر المزيد [+] اقل [-]Surfactant solubilization of hydrophobic compounds in soil and water. 1. Dodecylsulphate monomer and micellar partition coefficients for 28 polychlorinated biphenyls (PCBs) (41)
1994
Rahman, M.S. (Bangladesh Atomic Energy Commission, Dhaka (Bangladesh). Inst. of Food and Radiation Biology) | Paya-Perez, A.B. | Skejo-Andresen, H. | Larsen, B.R.
Reductions in the apparent soil-water partition coefficients (K(d)* ) for 28 polychlorinated biphenyls (PCBs) caused by the surfactant sodium dodecylsulphate (SDS) in the aqueous phase were studied. Above the critical micelle concentration (CMC) of the surfactant, K(d)* was reduced by 2-3 orders of magnitude, but even far below CMC at environmentally relevant surfacant concentrations significant reductions in Kd3 were observed. The plot of the soil-water partition coefficient (K(d)) divided by K(d)* versus the concentration of SDS allowed for the calculation of monomer (K(mn)(oc)) and micellar (K(mc)(oc)) surfactant-water parrition coefficients normalized to organic carbon for each PCB congener. K(mn)(oc) values were comparable with published values for the partition of PCBs between natural dissolved organic matter and lake water. K(mc)(oc) values were up to 30 times higher than K(mn)(oc) values and comparable with published octanol-water distribution coefficients. The findings of the present study underline the potential of surfactants at concentrations below their CMC to mobilize otherwise strongly bound hydrophobic compounds in soil-water systems.
اظهر المزيد [+] اقل [-]Polychlorinated dibenzo-p-dioxins (PCDDs) and furans (PCDFs) in urban air and deposition in the United Kingdom
1994
Duarte-Davidson, R. (Lancaster Univ. (United Kingdom). Inst. of Environmental and Biological Sciences) | Clayton, P. | Coleman, P. | Davis, B.J. | Halsall, C.J. | Harding-Jones, P. | Pettit, K. | Woodfield, M.J. | Jones, K.C.
Polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) have been monitored in air and deposition at four UK urban sites (London, Cardiff, Manchester and Stevenage) since the beginning of 1991; data from the first 2 years are presented here. Median Sigma 2,3,7,8-substituted PCDD/F concentrations in air were 3.2, 4.0, 3.5 and 2.6 pg/cubic metre respectively for London, Cardiff, Manchester and Stevenage. Median Sigma 2,3,7,8-substituted PCDD/F deposition fluxes were 1.5 ng/m** (2)/day in London, 1.4 ng/m** (2)/day in Cardiff and Manchester and 0.79 ng/m** (2)/day in Stevenage. Seasonal variations in the PCDD/F concentrations were observed at all sites for both air and deposition, with concentrations/fluxes generally elevated during the winter.
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