نتایج جستجو برای: organic nitrogen compounds
تعداد نتایج: 501616 فیلتر نتایج به سال:
Modelling wastewater treatment processes is an effective tool for prediction and analysis of treatment system performance. In this study, removal of organics and nitrogen compounds of municipal wastewater is simulated in a constructed wetland based on system dynamic approach using Stella software. In the developed model, organics are represented by BOD and nitrogen compounds including nitrate, ...
The removal of trace organic compounds (TrOCs) by a novel membrane distillation-thermophilic bioreactor (MDBR) system was examined. Salinity build-up and the thermophilic conditions to some extent adversely impacted the performance of the bioreactor, particularly the removal of total nitrogen and recalcitrant TrOCs. While most TrOCs were well removed by the thermophilic bioreactor, compounds co...
Heterocyclic nitrogen compounds are extensively used as intermediates in the manufacture of pesticides and herbicides, while their toxicity has been little reported (Chen et al, 1997). In this paper, we report the toxicity of 14 heterocyclic nitrogen compounds to Photobacterium phosphoreum measured by Microtox® test which has been proposed as a cost-effective prescreening procedure to eliminate...
In PNAS, we (1) highlight changes in the balance of oxidized and reduced nitrogen contributions to United States reactive nitrogen deposition, pointing out that decreases in nitrogen oxides (NOx) emissions, combined with modest growth in ammonia emissions, have altered the inorganic nitrogen deposition budget from majority deposition by oxidized species (nitric acid and nitrate) in the early 19...
Organics found in comet 81P/Wild 2 samples show a heterogeneous and unequilibrated distribution in abundance and composition. Some organics are similar, but not identical, to those in interplanetary dust particles and carbonaceous meteorites. A class of aromatic-poor organic material is also present. The organics are rich in oxygen and nitrogen compared with meteoritic organics. Aromatic compou...
Evaluation of corrosion inhibitors for steel in acidic media is important for some industrial facilities as well as is very interesting from theoretical aspects. Most of the effective inhibitors are organic compounds containing nitrogen, phosphorus and sulphur in their structures [1, 2]. Heteroatoms such as nitrogen, oxygen and sulphur are capable of forming coordinate covalent bond with metal ...
Relative to inorganic nitrogen, concentrations of dissolved organic nitrogen (DON) are often high, even in regions believed to be nitrogen-limited. The persistence of these high concentrations led to the view that the DON pool was largely refractory and therefore unimportant to plankton nutrition. Any DON that was utilized was believed to fuel bacterial production. More recent work, however, in...
Secondary organic aerosol (SOA) generated from the high-NO(x) photooxidation of isoprene was dissolved in water and irradiated with λ > 290 nm radiation to simulate direct photolytic processing of organics in atmospheric water droplets. High-resolution mass spectrometry was used to characterize the composition at four time intervals (0, 1, 2, and 4 h). Photolysis resulted in the decomposition o...
Chromatography is an analytical technique employed for purification and separation of organic and inorganic substances including characterisation and quantitative measurement of compounds (table). Basically there are two types: l. Gas chromatography (GC), 2. Liquid chromatography (LC). Although discovered in 1906 by Tshett, developed in the 1950s as the GC technique where the mobile phase are g...
Organic minerals, organic acids and NH-containing organic molecules represent important target molecules for astrobiology. Here, we present the results of the evaluation of a portable hand-held Raman spectrometer to detect these organic compounds outdoors under field conditions. These measurements were carried out during the February-March 2009 winter period in Austrian Alpine sites at temperat...
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