scholarly journals Research on the Transformation of Nitrogen during Hydrothermal Carbonization of Sludge

2018 ◽  
Vol 175 ◽  
pp. 01019
Author(s):  
Ying Sun ◽  
Qian Yang
Keyword(s):  
Thermal Decomposition ◽  
Liquid Phase ◽  
Total Nitrogen ◽  
Organic Nitrogen ◽  
Inorganic Nitrogen ◽  
Hydrothermal Carbonization ◽  
Ammonia Nitrogen ◽  
Carbonization Temperature ◽  
Nitrogen Compounds

The nitrogen in the sludge mainly exists in the form of inorganic nitrogen and organic nitrogen.In this paper, the transformation of nitrogen during the hydrothermal carbonization of sludge was studied.The results showed that during the hydrothermal carbonization of the sludge, both the total nitrogen and theinorganic nitrogen in hydrochar decrease with the increase of the carbonization temperature. The reason isthat part of the inorganic nitrogen compounds in the sludge undergoes thermal decomposition to releaseNH3, and some organic nitrogen will be hydrolyzed to produce ammonia nitrogen into the liquid phase.

An Improved Raney Catalyst Powder Method for Determination of Nitrogen in Fertilizers

1965 ◽  
Vol 48 (6) ◽  
pp. 1111-1115
Author(s):  
W G Burch ◽  
J A Brabson
Keyword(s):  
Sulfuric Acid ◽  
Total Nitrogen ◽  
Organic Nitrogen ◽  
Nitrogen Compounds ◽  
Test Results ◽  
Powder Method ◽  
Catalyst Powder ◽  
Good Agreement

Abstract With a Raney catalyst powder containing 10% Co, 40%; Ni, and 50% Al, nitrates are reduced to ammonia in 8N sulfuric acid in 10 minutes. Neither chlorides nor organic nitrogen compounds interfere with the reduction, and the reduction passed Youden’s ruggedness test. Results of analyses of fertilizers for total nitrogen that included reduction with the powder were in good agreement with those of accepted methods.

Forest detritus and cycling of nitrogen in a mountain lake

1991 ◽  
Vol 21 (7) ◽  
pp. 990-998 ◽  
Author(s):  
Robert C. Wissmar
Keyword(s):  
Total Nitrogen ◽  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Inorganic Nitrogen ◽  
Mountain Lake ◽  
Dissolved Inorganic Nitrogen ◽  
Microbial Oxidation ◽  
Nitrogen Fluxes ◽  
Nitrogen Concentrations ◽  
Definition Of

Small lakes of forested watersheds can receive large subsidies of forest matter, but little is known about the material's role in the cycling of nutrients within these ecosystems. This paper examines the influence of detritus and dissolved nitrogen from a forest on the nitrogen cycle of a small subalpine lake in the Cascade Mountains of Washington during the ice-free period (98 days). Relationships between changing detrital microbial biomass, oxygen uptake rates, and water conditions indicate that dissolved inorganic nitrogen concentrations and water temperatures control the decomposition of the nitrogen-depleted detritus. The microbial respiration rates suggest the probable co-occurrence of several microbial oxidation and reduction reactions that could be cycling nitrogen in oxic–anoxic interfaces of detrital deposits, sediments, and riparian areas. Estimates of nitrogen gains and losses (3 and 7%, respectively) by forest detritus are low in comparison with total nitrogen uptake and releases within the lake during the study period (378 and 347 mg•m−2, respectively) and point to the need to examine other methods for measuring detrital nitrogen fluxes. The total nitrogen input to the lake (2600 mg•m−2 for the study period) from the watershed exceeds the lake output (2120 mg•m−2 for the study period). The low output of total nitrogen appears to be due to retention of dissolved inorganic nitrogen and particulate organic nitrogen within the lake. Most dissolved inorganic nitrogen retained is nitrate suggesting possible losses through denitrification. Dissolved organic nitrogen is the major proportion of the total nitrogen fluxes, but related mass balance errors indicate the need for further definition of both the sources and fates of dissolved organic nitrogen for the ecosystem.

Nitrogen removal and cycling in restored wetlands used as filters of nutrients for agricultural runoff

1997 ◽  
Vol 35 (5) ◽  
pp. 255-261 ◽  
Author(s):  
Francisco A. Comín ◽  
Jose A. Romero ◽  
Valeria Astorga ◽  
Carmen García
Keyword(s):  
Total Nitrogen ◽  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Inorganic Nitrogen ◽  
Nitrogen Retention ◽  
Growing Season ◽  
Agricultural Runoff ◽  
Dissolved Inorganic Nitrogen ◽  
Restored Wetlands ◽  
Irrigation Network

Four restored wetlands dominated by Phragmites australis, Typha latifolia and Scirpus lacustris were used to improve the quality of agricultural runoff in the Delta of the Ebro River (NE Spain) in 1993. The wetlands were continuously flooded with water from a ricefield irrigation network during the growing season and received water with between 0-270 mg m−2d−1 of total nitrogen, 29-105 mg m−2d−1 of dissolved inorganic nitrogen and 0-27 mg m−2d−1 of dissolved organic nitrogen. Surface outflows contained between 0-80 mg m−2d−1 of total nitrogen, 0-12 mg m−2d−1 of dissolved inorganic nitrogen and 1-19 mg m−2d−1 of dissolved organic nitrogen. The nitrogen retention efficiency was close to 100% of the input, except for dissolved organic nitrogen at the end of the growing season. The denitrification rates measured by the acetylene reduction in the sediment ranged between 0 and 3.46 mg N m−2 d−1 and represented between 0 and 12% of the inflowing dissolved inorganic nitrogen. Emergent macrophytes accumulated between 20 and 100 mg N m−2 d−1, which accounts for between 66 and 100% of the inflowing dissolved inorganic nitrogen. The wetland sediment accumulated between 111 and 250 mg N m−2 d−1 during the six month growing season. The removal rate constants calculated according to a first - order plug - flow kinetics, were between 0.01-0.075 m d−1 for total nitrogen and 0.01-0.3 m d−1 for dissolved inorganic nitrogen. Plant uptake, detritus accumulation and decomposition, and nitrogen recycling in the sediment are major processes for nitrogen retention and recycling in the wetlands. This type of wetlands, restored from ricefields, act as highly efficient water polishing filters for agricultural runoff and, at the same time, can contribute to increase the habitat biodiversity of large areas where rice is cultivated extensively.

Tellurium as Catalyst in Semimicro Kjeldahl Method for Total Nitrogen Determination

1982 ◽  
Vol 65 (4) ◽  
pp. 786-790
Author(s):  
Christina F-H Liao
Keyword(s):  
Total Nitrogen ◽  
Organic Nitrogen ◽  
Complete Recovery ◽  
Nitrogen Compounds ◽  
Nitrogen Determination ◽  
Plant Soil ◽  
Clearing Time ◽  
Kjeldahl Digestion ◽  
Kjeldahl Method ◽  
Agricultural Materials

Abstract A modified semimicro Kjeldahl procedure is described for total nitrogen determination in agricultural materials and refractory organic nitrogen compounds, in which tellurium, alone or in combination with copper, is used as a catalyst. Tellurium alone is adequate for complete recovery of nitrogen from nicotinic acid if the acid:salt ratio is carefully controlled to nearly 1. However, when a mixture of tellurium and copper is used, complete nitrogen recovery could be obtained at a higher acidrsalt ratio. Use of a mixture also reduces clearing time when compared with copper alone in the Kjeldahl digestion. For samples containing nitrate, a Devarda's alloy (Cu:Al:Zn = 10:9:1) is proposed as a reducing agent in the pretreatment procedure to convert nitrate to ammonium in 6N H2SO4, with subsequent digestion of the sample by using a mixture of K2S04-catalyst and concentrated H2SO4. The proposed method is applicable for total nitrogen determination including NO3-N in plant, soil, and fertilizer samples.

scholarly journals Bio-assay of nitrogen available to two species of phytoplankton in an off-shore water

1957 ◽  
Vol 36 (1) ◽  
pp. 157-160 ◽  
Author(s):  
H. W. Harvey
Keyword(s):  
Organic Nitrogen ◽  
Sea Water ◽  
Inorganic Nitrogen ◽  
Nitrogen Compounds ◽  
Phytoplankton Species ◽  
Associated Bacteria ◽  
Total Inorganic Nitrogen ◽  
Bio Assay

A bio-assay of the nitrogen which was available to two phytoplankton species with their associated bacteria in an off-shore water is described.The concentrations found by assay (11·5 and 13μg N/1.) were similar to the concentration of total inorganic nitrogen compounds found by analysis (10μg N/1.).Of the organic nitrogen normally present in solution in sea water, an insignificant quantity appears to be available to the plant-bacteria community.

scholarly journals Effect of peat samples drying on measured content of carbon and nitrogen fractions

2013 ◽  
Vol 64 (4) ◽  
pp. 130-134 ◽  
Author(s):  
Jerzy Jonczak
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Total Nitrogen ◽  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Mineral Nitrogen ◽  
Nitrogen Compounds ◽  
Carbon And Nitrogen ◽  
Nitrogen Fractions ◽  
Initial Stage

Abstract The aim of the study was to compare the content of carbon and nitrogen fractions in fresh and dried samples of peat. The samples were extracted in 0.25 mol KCl·dm.-3, 0.25 mol H2SO4·dm.-3 and 2.5 mol H2SO4·dm.-3. Based on the extractions and analysis of total organic carbon (TOC) and total nitrogen (TN) following fractions of carbon and nitrogen were isolated: nonhydrolyzable carbon (NHC) and nitrogen (NHN), hardly hydrolyzable carbon (HHC) and nitrogen (HHN), easy hydrolyzable carbon (EHC) and nitrogen (EHN), dissolved organic nitrogen (DON), and its ammonium (NH4.-N) and nitrate (NO3.-N) form. Large differences between fresh and dried samples were observed in the content of some analyzed fractions . especially NO3.-N, NH4.-N, DON and HHC. 1.6.3.5 times higher concentrations of NO3.-N were observed in dry samples in comparison with fresh. In dried samples were also observed higher concentrations of NH4.-N and DON. In general lower concentrations of EHN, NHN, HHC and higher of HHN and EHC were observed in dried samples in comparison to fresh. Higher content of mineral nitrogen, as well as DON and DOC in dried samples, is probably an effect of mineralization of carbon and nitrogen compounds during initial stage of drying. The obtained data suggest, that the content of NO3.-N, NH4.-N, DON and EHC analyzed in dried samples of peat is overestimated. Extractions of the fractions from organic samples should be done based on fresh samples, just after sampling

scholarly journals Organic nitrogen in precipitation across Europe

2012 ◽  
Vol 9 (7) ◽  
pp. 8093-8109 ◽  
Author(s):  
J. N. Cape ◽  
Y. S. Tang ◽  
J. González-Benítez ◽  
M. Mitošinková ◽  
U. Makkonen ◽  
...  
Keyword(s):  
Total Nitrogen ◽  
Wet Deposition ◽  
Organic Nitrogen ◽  
Inorganic Nitrogen ◽  
N Deposition ◽  
Organic N ◽  
Single Source ◽  
Total N ◽  
Nitrogen Budgets ◽  
Nitrogen Concentrations

Abstract. Measurements of total nitrogen and inorganic nitrogen in precipitation samples from NitroEurope sites across Europe permit the calculation of organic nitrogen concentrations and wet deposition, by difference. The contribution of organic N to total N in precipitation ranged from only a few % to around 40% across sites from Northern Finland to Italy, similar to results from previous individual studies. This paper presents the absolute and relative contributions of organic N to wet N deposition across Europe, and examines seasonal trends. There were only weak correlations with other solutes in precipitation. These simple statistics indicate that sources of organic N in precipitation vary across Europe, and that no single source is responsible. The organic N contributes to total N deposition, yet this input is rarely quantified in nitrogen budgets.

scholarly journals Organic nitrogen in PM<sub>2.5</sub> aerosol at a forest site in the Southeast US

2009 ◽  
Vol 9 (4) ◽  
pp. 17157-17181 ◽  
Author(s):  
M. Lin ◽  
J. Walker ◽  
C. Geron ◽  
A. Khlystov
Keyword(s):  
Total Nitrogen ◽  
Organic Nitrogen ◽  
Inorganic Nitrogen ◽  
Nitrogen Concentration ◽  
Inorganic Ions ◽  
Total Carbon ◽  
Forest Site ◽  
N Budget ◽  
Back Trajectories ◽  
On Line

Abstract. There is growing evidence that organo-nitrogen compounds may constitute a significant fraction of the aerosol nitrogen (N) budget. However, very little is known about the abundance and origin of this aerosol fraction. In this study, the concentration of organic nitrogen (ON) and major inorganic ions in PM2.5 aerosol were measured at the Duke Forest Research Facility near Chapel Hill, NC, during January and June of 2007. A novel on-line instrument was used, which is based on the Steam Jet Aerosol Collector (SJAC) coupled to an on-line total carbon/total nitrogen analyzer and two on-line ion chromatographs. The concentration of ON was determined by tracking the difference in concentrations of total nitrogen and of inorganic nitrogen (determined as the sum of N-ammonium and N-nitrate). The time resolution of the instrument was 30 min with a detection limit for major aerosol components of ~0.1 μg m−3. Nitrogen in organic compounds contributed ~33% on average to the total nitrogen concentration in PM2.5, illustrating the importance of this aerosol component. Absolute concentrations of ON, however, were relatively low (<1.0 μg m−3) with an average of 0.18 μg m−3. The absolute and relative contribution of ON to the total aerosol nitrogen budget was practically the same in January and June. In January, the concentration of ON tended to be higher during the night and early morning, while in June it tended to be higher during the late afternoon and evening. Back-trajectories and correlation with wind direction indicate higher concentrations of ON in continental air than in marine air masses and indicate a variety of potential sources.

The Catabolism of Nitrogen Compounds in Dendrostomun cymodoceae Edmonds (Sipunculoidea)

1957 ◽  
Vol 8 (2) ◽  
pp. 131 ◽  
Author(s):  
SJ Edmonds
Keyword(s):  
Uric Acid ◽  
Amino Acid ◽  
Total Nitrogen ◽  
Ammonia Nitrogen ◽  
Nitrogen Compounds ◽  
Protein Nitrogen ◽  
Urea Nitrogen ◽  
Amino Acid Nitrogen ◽  
Sipunculus Nudus

The total non-protein nitrogen in the excretory products of fasting specimens of Dendrostomum cymodoceae Edmonds was found to be 1.18-1.40 mg N/100 g wet wt./24 hr. Of the total nitrogen, 83-90 per cent. was excreted as ammonia nitrogen, 4-6 percent, as urea nitrogen, 0-4 percent. as amino acid nitrogen, and none as uric acid; 89-94 percent. of the nitrogen was thus accounted for. The results are compared with the corresponding values obtained by other workers for Sipunculus nudus and some other invertebrates.

scholarly journals  Organic and inorganic nitrogen in precipitation and in forest throughfall at Bílý Kříž site (Beskydy Mts., Czech Republic)

2012 ◽  
Vol 58 (No. 2) ◽  
pp. 88-100 ◽  
Author(s):  
I. Drápelová
Keyword(s):  
Czech Republic ◽  
Nitrogen Deposition ◽  
Total Nitrogen ◽  
Organic Nitrogen ◽  
Inorganic Nitrogen ◽  
Organic N ◽  
Anthropogenic Source ◽  
Nitrogen Flux ◽  
The Czech Republic ◽  
Icp Forests

Organic nitrogen is an important but yet not very well explored component of nitrogen deposition. In this study concentrations and fluxes of organic and inorganic nitrogen in bulk precipitation in an open field (BOF) and in throughfall (THR) were evaluated at the B&iacute;l&yacute; Kř&iacute;ž experimental site (Moravian-Silesian Beskydy Mts., Czech Republic, 908 m a.s.l.) with a young Norway spruce stand. The results of a two-year study (2008 and 2009) were compared with the results obtained during the same time period on forest plots included in ICP Forests Programme in the Czech Republic. Total nitrogen deposition in BOF at the B&iacute;l&yacute; Kř&iacute;ž site amounted to about 918 mg&middot;m<sup>&ndash;2</sup>&middot;a<sup>&ndash;1</sup>, the contribution of organic nitrogen was about 8%. Total nitrogen flux with THR at B&iacute;l&yacute; Kř&iacute;ž was about 1,305 mg&middot;m<sup>&ndash;2</sup>&middot;a<sup>&ndash;1</sup> during the studied years and organic N accounted for 12% of this amount. The ranges of the two-year average values found for total nitrogen flux on ICP Forests plots throughout the Czech Republic were as follows: 759&ndash;1,857 mg N&middot;m<sup>&ndash;2</sup>&middot;a<sup>&ndash;1</sup> with 7&ndash;38% contribution of organic N in BOF and 928&ndash;3,816 mg N&middot;m<sup>&ndash;2</sup>&middot;a<sup>&ndash;1</sup> with 7&ndash;20% contribution of organic N in THR. The share of organic nitrogen in THR nitrogen fluxes at B&iacute;l&yacute; Kř&iacute;ž proved clear seasonality with maxima in July. A highly significant correlation between N-NH<sub>4</sub><sup>+</sup>&nbsp;&nbsp; and N-NO<sub>3</sub><sup>&ndash;</sup>&nbsp;&nbsp; concentrations in BOF suggested the common anthropogenic source of these substances at the B&iacute;l&yacute; Kř&iacute;ž site. No significant correlation was found either between organic N and N-NH<sub>4</sub><sup>+</sup> or between organic N and N-NO<sub>3</sub><sup>&ndash;</sup> concentrations in BOF. Cumulative deposition charts showed different behaviour of particular nitrogen deposition components while passing through the canopy. &nbsp; &nbsp;

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