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SINGH R KUMAR V SHARMA S BEHL RK SINGH BP NARULA N 《应用与环境生物学报》2005,11(6):751-755
ThepracticaluseofAzotobacterchroococcumasbiofertilizer hasbeenincreasinglyidentifiedinrecentyears.Oftentheefficacy ofthesebacteriaisassessedonthebasisofcropresponseswithout knowingthesurvival,persistenceandcompetitiveabilityofthein troducedstrain.Inoculat… 相似文献
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Bernhardt ES Colman BP Hochella MF Cardinale BJ Nisbet RM Richardson CJ Yin L 《Journal of environmental quality》2010,39(6):1954-1965
Growing concerns over the potential for unintended, adverse consequences of engineered nanoparticles (ENPs) in the environment have generated new research initiatives focused on understanding the ecological effects of ENPs. Almost nothing is currently known about the fate and transport of ENPs in environmental waters, soils, and sediments or about the biological impacts of ENPs in natural environments, and the bulk of modern nanotoxicogical research is focused on highly controlled laboratory studies with single species in simple media. In this paper, we provide an ecological perspective on the current state of knowledge regarding the likely environmental impacts of nanomaterials and propose a strategy for making rapid progress in new research in ecological nanoscience. 相似文献
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We describe a portable, non-motorized device for delivering a tracer dye into seawater under field conditions. Dye is ejected at a constant flow rate over a period of tens of minutes. The ejector works in a wide range of ambient pressures without external energy requirements. The flow rate is adjusted simply by varying the length of the delivery tube. The dye streams permitted observations of the upcurrent and downcurrent flow regimes for a filter-feeding crinoid (Comanthus bennetti) living at a depth of 8 m on a coral reef. The results indicate that the crinoid may enhance the rate of particle capture by changing the scale of turbulence in the water passing through the mesh of the filtration fan. 相似文献
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Benjamin P. Colman 《Environmental monitoring and assessment》2010,165(1-4):633-641
Across many environments, nitrate ( $\mbox{NO}_{3}^-$ ) is an important form of N available for microorganisms and photosynthetic organisms. Accurate $\mbox{NO}_{3}^-$ measurements are important for examining N cycling and retention in terrestrial and aquatic ecosystems, but a common method of $\mbox{NO}_{3}^-$ analysis can underestimate $\mbox{NO}_{3}^-$ concentrations when soluble iron is present (iron > 10 mg L???1). The basic method is robust, using copperized cadmium to reduce $\mbox{NO}_{3}^-$ and then diazotizing the resulting $\mbox{NO}_{2}^-$ in a two-step process to form an easily measured colored product. We show that iron interference is unique to using an NH4Cl and ethylenediaminetetraacetic acid (EDTA) buffer. We hypothesize that interference is through iron-catalyzed reduction of the intermediate color product, a diazonium ion. We examine three historical buffers as alternatives to NH4Cl/EDTA and recommend replacement of EDTA with diethylenetriaminepentaacetic acid, which chelates metals much like EDTA, but unlike EDTA, it does not cause interference in the presence of iron. 相似文献
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John A. Colman Richard F. Sanzolone 《Journal of the American Water Resources Association》1992,28(5):933-950
ABSTRACT: Geochemistry of fine-fraction streambed sediments collected from the upper illinois River basin was surveyed in the fall of 1987 as part of the U.S. Geological Survey National Water-Quality Assessment pilot projects. The survey included 567 samples analyzed for 46 elements. Three distinctive distribution patterns were found for seven U.S. Environmental Protection Agency priority pollutants surveyed, as well as for boron and phosphorus: (1) enrichment of elements in the Chicago urban area and in streams draining the urban area relative to rural areas, (2) enrichment in main stems relative to tributaries, and (3) enrichment in low-order streams at high-population-density sites relative to low-population-density sites. Significant differences in background concentrations, as measured by samples from low-order streams, were observed among five subbasins in the study area. Uncertain geochemical correspondence between low-order, background sites and high-order, generally metal enriched sites prevented determination of background levels that would be appropriate for high-order sites. The within-sample ratio of enriched elements was variable within the Chicago area but was constant in the Illinois River downstream from Chicago. Element ratios imply a composite fine-fraction sediment in the Illinois River of 35–40 percent Des Plaines River origin and 60–65 percent Kankakee River origin. 相似文献
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Soharu Anil BP Naveen Sil Arjun 《Journal of Material Cycles and Waste Management》2022,24(3):1037-1046
Journal of Material Cycles and Waste Management - In this study, an effort has been made to use concrete waste debris for the manufacturing of fly ash bricks as a sustainable material. Though in... 相似文献