خيارات البحث
النتائج 1 - 7 من 7
Factors Affecting Microbial Degradation of Polycyclic Aromatic Hydrocarbon Phenanthrene in the Caribbean Coastal Water
1999
Zaidi, B.R. | Imam, S.H.
Studies were conducted to assess factors that may influence the rate and extent of biodegradation of polyaromatic hydrocarbons (PAHs) in waters of Guayanilla Bay (latitude, 18°N; longitude, 66.45°W) Puerto Rico. Phenanthrene was used as a model PAHs compound. Both the rate and extent of phenanthrene degradation by natural microbial flora present in seawater samples from Guayanilla Bay were quite slow. Addition of KNO3 as a source of inorganic nitrogen (N) resulted in a 10-fold increase in the rate of phenanthrene degradation within a 125 h period, whereas, addition of K2HPO4 as a source of inorganic nutrient phosphorus (P) had no effect. Phenanthrene degradation was strongly inhibited when seawater pH was adjusted to 10.0. Phenanthrene in seawater samples degraded rapidly when first pretreated with hydrogen peroxide (H2O2) and then inoculated with a known indigenous phenanthrene degrading bacterium, Alteromonas sp. Pretreatment of phenanthrene with Triton-x-100 had little or no effect on its degradation by the same bacteria, whereas, degradation in samples preheated at 60°C was somewhat inhibited.
اظهر المزيد [+] اقل [-]Evaluation of hydroxyapatite as a metal immobilizing soil additive for the remediation of polluted soils. Part 1. Influence of hydroxyapatite on metal exchangeability in soil, plant growth and plant metal accumulation
1999
Boisson, J. | Ruttens, A. | Mench, M. | Vangronsveld, J. (INRA Bordeaux Aquitaine Research Center, Agronomy Unit, BP 81, F-33883 Villenave d'Ornon (France))
Evolution of heavy metals in marsh areas under rice farming
1999
Andreu, V. | Gimeno-Garcia, E. (Centro de Investigaciones sobre Desertificacion-CIDE - CSIC, Universitat de Valencia, Generalitat Valenciana, Cami de la Marjal s/n, 46470 Albal Valencia (Spain))
Fly ash application on two acid soils and its effect on soil salinity, pH, B, P and on ryegrass growth and composition
1999
Matsi, T. | Keramidas, V.Z. (Soil Science Laboratory, Aristotle University, Thessaloniki, 54006 (Greece))
Aliphatic hydrocarbons in an oil-contaminated soil : Carbon economy during microbiological decontamination
1999
Wibbe, Michael L. | Blanke, Michael M.
Microbial decontamination of hydrocarbon-polluted soil was paralleled with soil respiration measurements. About 1,500 tons of a loamy top soil were found to be contaminated with approximately 2000 mg/kg of aliphatic hydrocarbons, mainly oleic (C18:1) and linoleic acid (C18:2) found in the vicinity of a linoleum manufacturing and then a car dewaxing plant. The contaminated soil was analysed for dry matter, pH, dehydrogenase activity, electrical conductivity and nutrient content viz. nitrate, phosphorus and potassium, as well as a number of indigenous microbes. The soil was low in salt and nutrients. This paper describes the procedure and measures to decontaminate this bulk soil on site from approx. 2,000 to 500 mg of aliphatic hydrocarbons/kg dry matter by use of a nutrient emulsion, indigenous micro-organisms and aeration over 13 months. This 75% reduction in aliphatic hydrocarbons resulted in a concomitant carbon efflux, measured as soil respiration, and was used to calculate carbon fluxes.
اظهر المزيد [+] اقل [-]Key elements for lake ecological assessment: Latvian experience [45 lakes]
1999
Poikane, S. | Licite, V. (Latvian Environment Data Centre, Jurmala (Latvia))
Reducing phosphorus pollution in the Minnesota River
1999
Mathews, Leah Greden | Homans, Frances Reed | Easter, K. William