نتایج جستجو برای: dissolved nitrate

تعداد نتایج: 62972  

Maryam Mohammadi Rozbahani, Mohsen Bayat Zadeh Roya Zekavati

This study is descriptive - cross sectional and  during  the 8 months from  winter of 2012 to spring and summer 2013 was performed . In this study at first, with preparation and organization the questionnaire, information about  usage, type and functionality of household treatment systems were collected. Then from 20 Household water treatment ،after water treatment, the samples were taken. samp...

Journal: :Journal of environmental quality 2017
Raea M Gooding Helen M Baulch

There are few beneficial management practices (BMPs) with demonstrated efficacy in snowmelt-dominated regions. Small reservoirs are a BMP that can help mitigate flooding and reduce sediment transport, while reducing export of dissolved nutrients. To understand controls on nitrate removal and assess how this ecosystem service can be optimized, denitrification activity was measured in reservoirs ...

2006
M. W. Williams M. Knauf R. Cory N. Caine F. Liu

Here we characterize the nutrient content in the outflow of the Green Lake 5 rock glacier, located in the Green Lakes Valley of the Colorado Front Range. Dissolved organic carbon (DOC) was present in all samples with a mean concentration of 0·85 mg L. A one-way analysis of variance test shows no statistical difference in DOC amounts among surface waters (p = 0·42). Average nitrate concentration...

2006
Maeve C. Lohan Kenneth W. Bruland

The influence of the Columbia River plume on the distributions of nitrate and iron and their sources to coastal and shelf waters were examined. In contrast to other large estuaries, the Columbia River is a unique study area as it supplies very little nitrate (5 AM) and iron (14–30 nM) at salinities of 1–2 to coastal waters. Elevated nitrate and dissolved iron concentrations (as high as 20 AM an...

Journal: :international journal of environmental research 2010
j.i. nirmal kumar r.n. kumar s. viyol

methane is one of the important greenhouse gases that contribute to a rise in global mean surface temperature. aquatic environments are postulated to contribute > 50% of the total global methane (ch4) flux to the atmosphere (de angelis and lilley, 1987). dissolved methane concentration in surface waters was measured from january to december 2008 at two selected sites upper reaches (ongc bridge)...

Journal: :Anais da Academia Brasileira de Ciencias 2013
Elly R S de Souza Francisco C F de Paula

Rio da Serra watershed presents well preserved fragments of rain forest at the headwaters and small farms at middle and final stretches. These features allowed the study of fluvial hydrochemistry, under quasi pristine conditions. Sampling stations were established in order to represent the basin, and visited during dry, intermediate and wet periods. Obtained results are: temperature (22.1-28.6 ...

Journal: :Journal of medical entomology 2005
David R Mercer Sara L Sheeley Edward J Brown

Although they provide a number of valuable ecological services, wetlands also may harbor mosquitoes that are vectors of human pathogens. During 2002 and 2003, we measured biological (i.e., abundances of mosquitoes, other insects, and total heterotrophic bacteria, vegetational cover, and dead organic material), chemical (i.e., pH, dissolved nitrate, dissolved nitrite, dissolved phosphate, total ...

2006
Jack J. Middelburg Joop Nieuwenhuize

Ammonium and nitrate uptake was measured in 6 European tidal estuaries (Ems. Rhine, Scheldt, Loire, Gironde and Douro) using I5N-tracer techniques. Uptake rates of ammonium and nitrate ranged from 0.005 to 1.56 pmol N 1-' h-I and 0.00025 to 0.25 pmol N 1-' h-I, respectively, and differed significantly between and within estuaries. Analysis of nitrogen uptake using the relative preferential inde...

2002
Kitack Lee David M. Karl Jia-Zhong Zhang

[1] Nitrate availability is generally considered to be the limiting factor for oceanic new production and this concept is central in our observational and modeling efforts. However, recent time-series observations off Bermuda and Hawaii indicate a significant removal of total dissolved inorganic carbon (CT) in the absence of measurable nitrate. Here we estimate net carbon production in nitrate-...

2003
ROBERT S. STELZER JAMES HEFFERNAN

1. Although dissolved nutrients and the quality of particulate organic matter (POM) influence microbial processes in aquatic systems, these factors have rarely been considered simultaneously. We manipulated dissolved nutrient concentrations and POM type in three contiguous reaches (reference, nitrogen, nitrogen + phosphorus) of a low nutrient, thirdorder stream at Hubbard Brook Experimental For...

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