نتایج جستجو برای: surface sediments
تعداد نتایج: 658804 فیلتر نتایج به سال:
Thaumarchaeota are abundant and active in marine waters, where they contribute to aerobic ammonia oxidation and light-independent carbon fixation. The ecological function of thaumarchaeota in marine sediments, however, has rarely been investigated, even though marine sediments constitute the majority of the Earth's surface. Thaumarchaeota in the upper layer of sediments may contribute significa...
The numerical dominance and ecological role of psychrophilic bacteria in bottom sediments, sea ice, surface water and melt pools of the polar oceans were investigated using isolates, colony forming units (CFU) and metabolic activities. All sediment samples of the Southern Ocean studied showed a clear numerical dominance of cold-loving bacteria. In Arctic sediments underlying the influence of co...
The combinatorial bio/chemical investigation of sediments (six surface samples and one core sample) from Osaka Bay, Japan was conducted to clarify the horizontal and vertical distribution profiles of persistent organic pollutants in the sediments. Concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), polybrominated dibenzo-p-dioxins a...
background: the pollution of the aquatic environment with heavy metals has become a worldwide problem during recent years, due to their potential toxic effects and ability to bio-accumulate in aquatic ecosystems. heavy metals are sensitive indicators for monitoring changes in the aquatic environment. methods: in this study, total concentrations of cr, pb, cu, zn, and fe were measured in water a...
background: soil and sediment serve as major reservoir for contaminants as they possess ability to bind various chemicals together. in this study the concentrations of heavy metals cd, cr and cu were analyzed in surface sediments of agh gel wetland in west of iran. methods: the sediment samples were taken from 10 stations. the samples were subjected to bulk digestion and chemical partitioning a...
background and purpose: the heavy metal pollution and its fractionations in the surface sediments of darreh-morad beyg river, hamedan city were monitored for cd, cr, cu, fe, ni, pb, and zn in 2014. materials and methods: totally 30 surface sediment samples were taken from 10 stations with three replicates. the samples subjected to bulk digestion and chemical partitioning. the concentrations o...
Background and purpose: Today, environmental pollution, especially pollution of aquatic ecosystems, humans and other organisms are faced with serious problems. Endocrine disrupting chemicals are one group of chemical compounds that are important because of their significant adverse effects in humans and animals. Therefore, this study aimed to determine the concentration of 4-Nonylphenol, Bisphe...
This study was conducted to determine some heavy metals (Fe, Mg, Cr, Ni) of surface sediment in the southern Caspian Sea during two seasons (Summer and Winter) in 2014-2015. 36 surface sediments samples (with triplicate) were collected at two stations (Tonekabon and Bandar Amirabad). All samples were analyzed using sequential extraction to indicate natural and anthropogenic sources. The results...
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