Refine search
Results 1-10 of 72
Niveaux d' ozone et endommagement foliaire sur quelques essences mediterraneennes.
2001
Dalstein L. | Teton S. | Cottereau C. | Vas N.
En France, dans les Alpes-Maritimes, une recherche est menee pour connaitre l' impact eventuel de l' ozone sur l' endommagement foliaire repere ces dernieres annees sur peuplements de pins d' Alep, sylvestre et cembro. L' etude s' effectue dans le cadre d' un contrat franco-italien Interreg 2 et d' un programme Primequal. Cet article donne tout d' abord, les resultats pour l' ete 1999, interessant les niveaux de concentration d' ozone mesures depuis le littoral azureen jusqu' au massif du Mercantour au moyen d' analyseurs physico-chimiques et de capteurs passifs. La dose d' AOT 40 et la somme cumulee des concentrations horaires sont indiquees pour les periodes de mesure estivales. Les capteurs passifs se situent notamment parmi des placettes de suivi d' arbres. Afin d' apprehender l' impact de la pollution par l' ozone sur ces ecosystemes forestiers, des notations d' endommagement foliaire sont effectuees. Des correspondances sont recherchees entre les niveaux moyens d' ozone et les degres d' atteinte des trois principales essences suivies (pins d' Alep, sylvestre et cembro). Il semble y avoir une correlation entre augmentation des concentrations d' ozone et endommagement foliaire au moins en ce qui concerne les pins cembro.
Show more [+] Less [-]Bioreactors for waste gas treatment
2001
Kennes, C. | Veiga, M. C.
The treatment of polluted air by passing it through biological filters is proving more effective and less expensive than conventional physical and chemical technologies. This book overviews the major bioreactor designs currently available on the market. The first part explains the principles of the different techniques, followed by descriptions of full-scale bioreactor applications for each system. Topics of the 14 chapters include biotrickling filters, membrane bioreactors, rotating biological contactors, activated sludge, biofiltration of waste gases from a dairy industry, and a bioscrubber for cleaning waste gases from wastewater treatment plants. c. Book News Inc.
Show more [+] Less [-]Agricultural nonpoint source pollution
2001
Ritter, William F. | Shirmohammadi, Adel
Economic losses from marine pollution
2001
Ofiara, Douglas D. | Seneca, Joseph J.
Marine pollution causes significant damage to fisheries and other economically productive uses of the ocean. The value of that damage can be quantified by economists, but the meanings of those valuations and how they are derived are often obscure to noneconomists. Economic Losses from Marine Pollution brings a fuller understanding of the variety and extent of marine losses and how they are assessed to scientists, lawyers, and environmentalists by systematically identifying and classifying marine losses and relating them to models and methods of economic valuation. The authors use a step-by-step approach to show how economists have used these methods and how they approach the problem of assessing economic damage. The book begins by describing the importance of economic valuation of marine damages, the history of concern over marine pollution, and the development of economic methodologies to assess damage from it. Following that, the book: considers types of marine pollution and their effects on organisms, ecosystems, and humans, and the corresponding economic effects of those biological impacts introduces the economic principles and methods needed to understand and to assess economic damages expresses losses from water quality impairments in terms of economic value introduces the basic economic techniques that have been developed and used to measure changes in economic value discusses how to apply those economic techniques, and presents a variety of practical examples explores limitations and problems that can arise in such applied work. Economic Losses from Marine Pollution includes all of the relevant economic theory together with specific examples of how that theory has been and can be applied. It offers environmental professionals with little or no background in economics the basic economic tools needed to understand economic valuations of environmental damage. --Publisher.
Show more [+] Less [-]Application of Different Extraction Methods for the Quality Control of Water
2001
Buszewski, Boguslaw | Ligor, Tomasz
The determination of chlorocarbons in drinking wateris described. The chlorocarbons studied include:tetrachloromethane, 1,1,1-trichloroethane, tribromomethane,bromodichloromethane, dibromochloromethane. Three methods ofsample preparation were compared: liquid-liquid extraction(LLE), purge & trap (P&T) and direct aqueous injection (DAI).The samples of drinking water were taken from Toruń (Poland):local sources, municipal water intake, drilled wells. Theobtained data allowed to create the map of chlorocarbonscontamination for Toruń town. Repeatability, linearity anddetection limits of LLE, P&T, DAI were evaluated forhalocarbons under investigation.
Show more [+] Less [-]Effects of H2SO4 and HNO3 on Soil Acidification and Aluminum Speciation in Variable and Constant Charge Soils
2001
Xu, R. K. | Ji, G. L.
The difference in effect on acidification and species of aluminum speciation between HNO₃ and H₂SO₄for two contrasting types of soils in surface charge was investigated. The results show that the effect of H₂SO₄ on acidification of variable charge soils (Ferric Acrisol and Haplic Acrisol) of subtropical regions wasweaker than that of HNO₃, due to the specific adsorption of SO₄ ²⁻ and the accompanied release of OH⁻. For two constant charge soils, Haplic Luvisol andEutric Cambisol, the difference in effect between the two acids is small. The concentrations of total inorganic monomeric aluminum, Al³⁺, Al-F complexes and Al-SO₄complexes in the extract from variable charge soils are alsolower in H₂SO₄ systems than those in HNO₃ systems, whereas the reverse is true for constant charge soils, except the concentration of Al³⁺. For variable charge soils, Al-F complexes are the major species of inorganic monomeric aluminum at high pH butAl³⁺ might contribute to a largepart at low pH, while for constant charge soils Al-F complexes contribute almost exclusively to the inorganic monomeric aluminum. The presence of a large amount of SO₄ ²⁻ in the extract from the constant charge soilsleads to a higher proportion of Al-SO₄ complexes in totalinorganic monomeric aluminum than that from variable charge soil, although the numerical value of proportion is small.
Show more [+] Less [-]Antimony as a Tracer of the Anthropogenic Influence on Soils and Estuarine Sediments
2001
Cal-Prieto, M. J. | Carlosena, A. | Andrade, J. M. | Martínez, M. L. | Muniategui, S. | López-Mahía, P. | Prada, D.
The aim of this work was to evaluate antimony (Sb) as apotentially valuable tracer of the anthropogenic impact on soilsand estuarine sediments. Antimony was determined in fifteenroadsoils from a medium-size city, La Coruña (NW of Spain);and twelve sediments from two estuaries (La Coruña and Ares-Betanzos). Sb determination was accomplished in a rapid andreliable way by directly measuring the solid samples with anautomatic ultrasonic slurry sampling-ETAAS device. Soil contentsranged from 0.29 to 8.81 μg g⁻¹. A relation between Sbconcentration and motor vehicle intensity was observed.Regarding estuarine sediments, Sb amounted from 0.22 to 1.51 μg g⁻¹, for the La Coruña estuary and 0.24 to 0.71 μg g⁻¹, forthe Ares-Betanzos estuary; higher Sb values were found forcoastal locations whereas lower contents corresponded to `inner'samples. In order to confirm these findings, other pollutantswere studied: As, Cd, Co, Cr, Cu, Ni, Pb, Zn, aliphatichydrocarbons (AH) and polycyclic aromatic hydrocarbons (PAH).These values, along with the Sb ones, were subjected tomultivariate studies intended to elucidate whether Sb correlated(and to what extent) to other well-known anthropogenic pollutants. Thus, Sb became associated to Cd, Cu, Pb and Zn in road soils and to As, Cu, Zn, PAH, Pb and unresolved hydrocarbons, in sediments.
Show more [+] Less [-]Nitrous Oxide Emission from Soil with Different Fertilizers, Water Levels and Nitrification Inhibitors
2001
Pathak, Himanshu | Nedwell, D. B.
The effects of urea, (NH₄)₂SO₄, KNO₃, and NH₄NO₃ on nitrous oxide (N₂O) emission from soil at field capacity and submerged condition were studied during 120 days in the laboratory. Soils in both moisture regimes gave higher emissions in the beginning, which were reduced later. Total emission of N₂O was higher at submergence as compared to field capacity regardless of fertilizer type. At field capacity soil fertilized with ureaemitted the highest amount of N₂O (1903 μg N₂O-N kg⁻¹ soil) during 120 days while at submerged condition, soil with NH₄NO₃ gave the highest emission (4843 μg N₂O-N kg⁻¹ soil). In another study, the efficacy of seven nitrification inhibitors in reducing the emission of N₂O-N from soil fertilized with urea was tested in the laboratory. Nitrapyrin, 2-amino-4-chloro-6-methylpyrimidine (AM), and dicyandiamide (DCD) reduced the emission to 12, 24, and 63% that of urea, respectively, whereas sodium thiosulphate, sulphur, acetylene,and thiourea had no effect on emission of N₂O. In submerged conditions none of the inhibitors reduced the emission.
Show more [+] Less [-]Distribution of Trace Elements in Tissues of Two Shrimp Species from Persian Gulf and Effects of Storage Temperature on Elements Transportation
2001
Pourang, N. | Amini, G.
This study is focussed on evaluation of temperature effectduring frozen storage on movement of trace elements in differenttissues (exoskeleton, carapace and abdominal muscle) of twocommercially important shrimp species (Penaeusmerguiensis and Metapenaues affinis). Moreoverrelationships between total length and sex of specimens with concentration of trace elements in selected tissues were assessed. Concentrations of Cd, Cr, Cu, Fe, Mn, Ni and Znin samples were determined by ICP-AES. Only in the case of Niand Zn sex related differences could be observed. With theexception of Cu, the trace metals distributed significantlydifferent between the tissues. The only significant differencesbetween species were found in bioaccumulation of Mn. Sizedependent relationship was observed only for Ni. Associationsbetween Mn and Fe were positively and highly significant in allthe cases. The levels of all the metals in muscle of the shrimpsfrom the studied region were comparable to other world areas. MeanCu and Zn levels in edible parts of M. affinis stored at–10 °C exceeded some existing guidelines, while the concentrations at –30 °C were somewhat lower than them.
Show more [+] Less [-]