خيارات البحث
النتائج 271 - 280 من 368
Effect of copper smelting air pollution on the mites (Acari) associated with young Scots pine forests polluted by a copper smelting works at Giogów,Poland. I. Arboreal mites
1997
Seniczak, Stanisław | Dąbrowski, Janusz | DŁUGOSZ, JACEK
The arboreal mites and epiphytes in young Scots pine forests (plant association Leucobryo-Pinetum) polluted by a copper smelting works at Głogów, were investigated. The concentration of heavy metals in Scots pine bark and epiphytes increased towards the pollution source. Copper was accumulated mainly by algae, but lead was accumulated mainly by lichens; these epiphytes accumulated more heavy metals than tree bark. A high concentration of heavy metals was harmful to mites, especially to Oribatida, and to lichens, but algae tolerated these pollutants. The number of oribatid species decreased towards the pollution source, along with the increasing concentrations of heavy metals in tree bark and epiphytes. Among mites, the following categories were distinguished: a) sensitive to heavy metals, b) sensitive to a high concentration but tolerant of small concentrations and c) tolerant of these metals. The mites inhabited mainly the lower section of trees.
اظهر المزيد [+] اقل [-]Ammonia stripping as a pretreatment for landfill leachate
1997
Cheung, K. C. | CHU, L. M. | Wong, M. H.
The effectiveness of ammonia stripping at different air flow rates (0, 1 and 5 L min⁻¹) and lime dosages (0 and 10 000 mg L⁻¹ calcium hydroxide) was investigated in aeration tanks in a laboratory as a pretreatment to remove ammoniacal-nitrogen and organic load (COD) in landfill leachate. Ammoniacal-nitrogen removal at 20 °C after one day was 70% for 0 L min⁻¹, 81% for 1 L min⁻¹ and 90% for 5 L min⁻¹ regardless of the origin of leachate. Ammonia loss was mainly due to desorption through water surface. The levels of phosphorus and COD were only reduced by lime precipitation, with 85% and 93% phosphorus removal and 24% and 47% COD removed for leachate from the Junk Bay Landfill (JB) and Gin Drinkers' Bay Landfill (GDB) respectively. The highly significant difference (P<0.05) of COD removal between JB and GDB might be due to the different age of the two landfills studied. Leachate quality and configuration of the treatment reactor were important factors affecting the efficiency of ammonia removal by stripping processes.
اظهر المزيد [+] اقل [-]Organochlorine residues in deep-sea organisms from Suruga Bay, Japan
1997
Lee JongSu | Tanabe, S. | Takemoto, N. | Kubodera, T. (Department of Environment Conservation, Ehime University, Tarumi 3-5-7, Matsuyama 790 (Japan))
Abnormalities in the reproductive health of flounder Platichthys flesus exposed to effluent from sewage treatment works
1997
Lye, C.M. | Frid, C.L.J. | Gill, M.E. | McCormick, D. (Dove Marine Laboratory, University of Newcastle upon Tyne, Cullercoats, North Shields NE30 4PZ (United Kingdom))
Fluxes and budgets of contaminants in the German Bight
1997
Sundermann, J. | Radach, G. (Zentrum fur Meeres-und Klimaforschung der Universitat Hamburg, Institut fur Meereskunde, 22529 Hamburg (Germany))
Concentrations of Cd, Pb, Zn and Cu in pristine wetlands of the Russian Arctic
1997
Zhulidov, A.V. | Headley, J.V. | Robarts, R.D. | Nikanorov, A.M. | Ischenko, A.A. | Champ, M.A. (Hydrochemical Institute, Federal Services of Russia for Hydrometeorology and Environmental Monitoring, Stachki Ave. 198, Rostov-on-Don 344104 (Russian Federation))
Fluxes and mass balances of nutrients in a semi-intensive shrimp farm in north-western Mexico
1997
Paez-Osuna, F. | Guerrero-Galvan, S.R. | Ruiz-Fernandez, A.C. | Espinoza-Angulo, R. (Laboratorio de Quimica Marina, Instituto de Ciencias del Mar y Limnologia, Universidad Nacional Autonoma de Mexico, Apdo. Postal 811, Mazatlan 82000, Sinaloa (Mexico))
QUASIMEME: quality measurements for marine monitoring. Review of the EU project 1993-1996
1997
Topping, G. (ed.)
A comparison of the bivalve species Donax deltoides and Mytilus edulis as monitors of metal exposure from effluent discharges along the Ninety Mile Beach, Victoria, Australia
1997
Haynes, D. | Leeder, J. | Rayment, P. (Gippsland Water, PO Box 348, Traralgon 3844 (Australia))
Diagnosis of boron, fluorine, lead, nickel and zinc toxicity in citrus plantations in villarreal, spain
1997
Aucejo, Antonio | Ferrer, José | Gabaldón, Carmen | Marzal, Paula | Seco, Aurora
In the late 1980s, citrus plantations in the area of Villarreal (Spain) showed injuries similar to those previously reported for boron and fluorine toxicity. The area was affected by the disposal of industrial wastewater, mainly from ceramic industries. Conjunctive uses of surface water, groundwater and wastewater for irrigation had taken place. A survey was conducted at 25 orchards to assess leaves and soil for their boron, fluorine, lead, nickel and zinc contents. Wastewater and groundwater were also analyzed to corroborate the presence of these pollutants. The results showed that both boron and fluorine contents were greater than those reported as excess at the most part of the orchards included in the study. Heavy metals toxicity effects were not confirmed. Boron pollution was attributed to industrial wastewater spills and fluorine contamination from atmospheric pollution.
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