scholarly journals Dynamics of mineral nitrogen compounds in the waters of the Dniester River

2021 ◽  
Author(s):  
Petru Ciorba ◽  
◽  
Elena Zubcov ◽  
Nina Bagrin ◽  
Liliana Teodorof ◽  
...  
Keyword(s):  
Total Nitrogen ◽  
Water Samples ◽  
Seasonal Dynamics ◽  
Organic Nitrogen ◽  
Mineral Nitrogen ◽  
Ion Concentration ◽  
Ammonium Ion ◽  
Nitrogen Compounds ◽  
Ammonium Ions ◽  
Nitrate Ions

This article presents the results of studying the content of mineral (ammonium ions, nitrites and nitrates) and organic nitrogen compounds in water samples collected from the Dniester river in 2020. In the study are examines the seasonal dynamics of the forms of mineral nitrogen, total nitrogen and the correlation between organic and mineral nitrogen. Limits of ammonium ion concentration in the Dniester river varied between 0.002 mg N/l and 0.93 mg N/l, nitrite ions 0.002 mg N/l and 0.05 mg N/l, nitrate ions 0.002 mg N/l - 1.36 mg N/l.

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 Dinamica compușilor azotului mineral în apele râului Prut

2021 ◽  
Author(s):  
Petru Ciorba ◽  
Keyword(s):  
Seasonal Dynamics ◽  
Mineral Nitrogen ◽  
Nitrogen Compounds ◽  
Ammonium Ions ◽  
Autumn Period ◽  
Prut River

In this article the results on the content of mineral nitrogen compounds (ammonium ions, nitrites and nitrates) during 2020 year in the Prut River Braniște – Giurgiulesti sector are presented. In the study is examinated the seasonal dynamics of these parameters in the winter – spring – summer – autumn period. The range of ammonium ions in the waters of the Prut River varies from 0.002 to 0.26 mgN /L, of nitrite – from 0.002 to 0.02 mgN /L and of nitrates – from 0.002 to 0.73 mgN /L, the maximums being lower than in 2009-2010, and much lower than in the 80s-90s of the last century.

In-Situ Leaching of South Texas Uranium Ores-Part 2: Oxidative Removal of Adsorbed Ammonium Ions With Sodium Hypochlorite

1983 ◽  
Vol 23 (02) ◽  
pp. 387-396 ◽  
Author(s):  
J.M. Paul ◽  
W.F. Johnson ◽  
A. Fletcher ◽  
P.B. Venuto
Keyword(s):  
Cation Exchange ◽  
Sodium Hypochlorite ◽  
Geographical Area ◽  
Ammonium Bicarbonate ◽  
South Texas ◽  
Ion Concentration ◽  
Ammonium Ion ◽  
Side Reactions ◽  
Ammonium Ions

Abstract This paper reports a laboratory study of the oxidative destruction by sodium hypochlorite (NaOCl) of ammonium ions adsorbed on relatively reduced south Texas uranium ore. Included are an assessment of reaction stoichiometry, determination of some major reaction pathways and side reactions, and identification of several pathways and side reactions, and identification of several intermediates. Adsorbed ammonium ions were completely removed by 0.5 % NaOCl, with the concentration of NH3 in the effluent falling to a very low value after 10 to 15 PV NaOCl oxidant. A small fraction (5 to 10%) of NaOCl was utilized in reacting with NH3. After the NH3 was nearly depleted, mono-, di-, and trichloramines, the expected intermediates in NaOCl oxidation of NH3, were observed. Chloramine decomposition studies showed that all three decomposed completely within 12 days. Since the ore was relatively highly reducing, the major pan of the NaOCl was, not unexpectedly, consumed in side reactions. Substantial quantities of sulfate, reflecting oxidation of sulfide minerals such as pyrite, were formed, large amounts of uranium were leached out, and substantial amounts of calcium and magnesium ions were also produced during the presaturation with NH4HCO3 preceding the oxidation stage. Introduction A leachate that has sometimes been used for in-situ leaching of uranium ores is a solution of ammonium bicarbonate (NH4HCO3) containing an oxidant-usually hydrogen peroxide (H2O2) or oxygen (O2). The ammonium ion (NH4+) introduced into the ore body upon injection of this leachate is exchanged for cations such as calcium (Ca+2 ) and sodium (Na+), which are associated with mineral species in the formation possessing available cation exchange sites. As the indigenous groundwaters reinvade the leached zone, the adsorption process is reversed with NH4+ ions being displaced from process is reversed with NH4+ ions being displaced from the cation exchange sites and returned to the ground-waters. In general, this latter process maintains the ammonia (NH3 (or NH4+ ion) concentration well above the baseline (pre-mining) value in groundwater for extended periods of time in waters produced from wells in or near the mined zone following cessation of leachate injection. Prior to abandonment of an in-situ leach-mining site by the operator, satisfactory restoration of groundwater quality must be demonstrated. Requirements for this demonstration vary with the geographical area. A summary of applicable regulations has been provided by Kasper et al. A review of the state of restoration demonstrations to Sept. 1979 has been given by Tiepel. Most of the in-situ leach operations in south Texas have been conducted in aquifers containing indigenous waters with TDS contents in the 700- to 3,000-ppm range. Ca+ 2, magnesium (Mg+2), and bicarbonate ion (HCO3 ) concentrations are high in these slightly alkaline waters. These equilibrium water compositions indicate that an appreciable fraction of the interlayer ion exchange sites of the smectite clays in the formation are occupied by Ca+2 or Mg+2 ions. SPEJ P. 387

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.

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.

Investigation on the Efficiency of Effective Microorganisms for Polluted Water Treatment

2021 ◽  
Author(s):  
Mun Wei Se Hoo ◽  
Swee-Sen Teo
Keyword(s):  
Water Samples ◽  
Nitrate Concentration ◽  
Optimum Concentration ◽  
Water Bodies ◽  
Ion Concentration ◽  
Synthetic Wastewater ◽  
Ammonium Ion ◽  
Polluted Water ◽  
Human Consumption ◽  
Effective Microorganisms

Water pollution, mainly caused by rapid industrialization and population growth, has been one of the major threats to the sustainability of living organisms. The urgency to preserve and restore the freshwater system has never been clearer, as only 1% of the world's total water supply is suitable for human consumption. Recently, biological treatment using Effective Microorganisms Activated Solution (EMAS) shows potential in reducing pollution in wastewater and river water bodies. Thus, this study aims to assess the water quality of water bodies in Malaysia, namely Kerayong River and Pandan Perdana Lake, and assess the effectiveness and optimum concentration of EMAS on polluted water. The results obtained showed that high levels of NO2- , NO3- and NH3 were found in excess in Kerayong River, indicating pollution occurs whereas none of the tested parameters were detected in excess in Pandan Perdana Lake, hence showing it was not contaminated. The effectiveness of EMAS on synthetic wastewater was assessed through the measurement of few parameters which include Ca2+, Na+ , K+ , NO3- , NH4+ , pH and microbe concentration. It was found that in all concentrations of EMAS, ammonium ion concentration was effectively reduced, and microbe concentration was increased (p < 0.05). EMA (1 mL/L) and EMB (0.2 mL/L) samples had significantly lower nitrate concentration compared to the control samples. EMAS were not capable to reduce dissolved water minerals such as Ca2+, Na+ and K+ , but further contributes to the increase of dissolved minerals in the water. Whereas no significant effect of EMAS on pH of water samples was observed as all water samples fall within pH of 4.31 to 4.56 throughout 5 days. EMAS concentration of 1 mL/L was the optimum concentration for reducing ammonium and nitrate concentration.

STUDIES REGARDING THE DETERMINATION OF NITRITE IONS CONCENTRATION IN THE DUMBRAVITA AREA DRINKING WATER (FOUNTAIN WATER)

2020 ◽  
Vol 34 (1) ◽  
pp. 39-48
Author(s):  
Aurica Pop ◽  
Keyword(s):  
Drinking Water ◽  
Sodium Nitrate ◽  
Water Samples ◽  
Ammonium Ion ◽  
Measuring Device ◽  
Nitrate Ions ◽  
Method Selection ◽  
Nitrite Nitrogen ◽  
The Village

The paper showcases studies conducted in order to determine the existence of nitrate ions in the drinking water (fountain water) of a common household from the village of Dumbravita, Maramures County, Romania, as well as to determine the Romplumb S.A. wastewater ammonium ion. A Hanna Instruments photo colorimeter for boilers and cooling cannons was used in order to determine the nitrate ions concentration, which is a compact and versatile measuring device that can measure absorption and pH/mV, as well as a HR Hanna Nitrite photometer. Determining the ammonium ion was possible with the help of a multi parameter photo colorimeter, which employs the CAL Check function. In order to determine de nitrate ions concentration in the water samples, a photo colorimeter which employs the "Method selection"," Zero", "Read" and "Timers" functions was used. Using the "Nitrite LR" method, the device displays de nitrite-nitrogen (NO2--N) concentration measured in gg/l, and by accessing the secondary functions using the Chem Frm key, the result can be converted in gg/l of nitrite (NO2-) and sodium nitrate (NaNO2).

scholarly journals Response surface methodology (RSM) and its application for optimization of ammonium ions removal from aqueous solutions by pumice as a natural and low cost adsorbent

2016 ◽  
Vol 42 (2) ◽  
pp. 33-43 ◽  
Author(s):  
Masoud Moradi ◽  
Mehdi Fazlzadehdavil ◽  
Meghdad Pirsaheb ◽  
Yadollah Mansouri ◽  
Touba Khosravi ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Contact Time ◽  
Fourier Transforms ◽  
Low Cost ◽  
Chemical Properties ◽  
Ion Concentration ◽  
Ammonium Ion ◽  
Ammonium Ions ◽  
Mixing Rate

Abstract This research was conducted to study the adsorption of ammonium ions onto pumice as a natural and low-cost adsorbent. The physico-chemical properties of the pumice granular were characterized by X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Modeling and optimization of a NH4+ sorption process was accomplished by varying four independent parameters (pumice dosage, initial ammonium ion concentration, mixing rate and contact time) using a central composite design (CCD) under response surface methodology (RSM). The optimum conditions for maximum removal of NH4+ (70.3%) were found to be 100 g, 20 mg/l, 300 rpm and 180 min, for pumice dosage, initial NH4+ ion concentration, mixing rate and contact time. It was found that the NH4+ adsorption on the pumice granular was dependent on adsorbent dosage and initial ammonium ion concentration. NH4+ was increased due to decrease the initial concentration of NH4 and increase the contact time, mixing rate and amount of adsorbent.

Water uptake and trans-potential in sunflower roots as influenced by ammonium ions

1980 ◽  
Vol 94 (1) ◽  
pp. 145-150 ◽  
Author(s):  
S. M. Ragab
Keyword(s):  
Water Uptake ◽  
Water Movement ◽  
External Medium ◽  
Xylem Sap ◽  
Ion Concentration ◽  
Ammonium Ion ◽  
Ammonium Ions ◽  
Root Cells ◽  
Uptake Inhibition ◽  
Root Potential

SummaryThe effect of ammonium ions on artificially imposed water flux and trans-root potential difference was studied in excised sunflower roots. Water movement through the root system decreased and the potential of the xylem sap became less negative with respect to the external medium as the ammonium ion concentration in the external medium increased. It is suggested that ammonium ions appeared to inhibit water uptake either wholly or partially through a general or specific blockage of root metabolism which reflected on the permeability of water through root membranes. The reduction in the trans-root potential was due to the effect of ammonium ions on the original trans-root potential of epidermal root cells. This may indicate that the site of water uptake inhibition lies within the root epidermis.

scholarly journals STUDY OF THE SORPTION OF AMMONIUM CATIONS ON A FIBROUS CARBOXYLIC SORBENT

2021 ◽  
Vol 18 (38) ◽  
pp. 224-241
Author(s):  
Yuri Semenovich PEREGUDOV ◽  
Elena Mikhailovna GORBUNOVA ◽  
Behzod Aminovich OBIDOV ◽  
Ksenia Borisovna KIM ◽  
Sabuhi Ilich oglu NIFTALIEV
Keyword(s):  
Neural Networks ◽  
Mineral Fertilizer ◽  
Distribution Coefficients ◽  
Ion Concentration ◽  
Ammonium Ion ◽  
Coefficient Of Determination ◽  
Ammonium Ions ◽  
Sorption Data ◽  
Developed Surface ◽  
Degree Of Recovery

Background: Wastewater from the mineral fertilizer production, agribusiness containing ammonium ions causes significant harm to fish farming; therefore, it must be purified before discharge. Ion-exchange sorption is a promising method for isolating ammonium cations. The object of the study was a chemisorption fiber VION KN-1, which has developed surface and high sorption rate. Purpose: To study the sorption kinetics of ammonium cations from aqueous solutions on VION KN-1; to train an ANN to predict the degree of recovery of ammonium ions from wastewater using Statistica Neural Networks Version 13. Methods: The ammonium ion concentration in the solution was established by direct potentiometry. Sorption isotherms were constructed using the method of variable concentrations. To determine the limiting stage, the obtained kinetic dependencies were represented in the coordinates of the Boyd-Adamson equations for internal/external diffusion. Results and Discussion: During sorption from solutions with different ammonium nitrogen contents, the values of distribution coefficients (Kd) are at the level of 2.3ꞏ103 cm3/g, which significantly exceeds this parameter for granular ionites. Experimental sorption data were verified using Freundlich (R2 = 0.9224) and Langmuir (R2 = 0.9996) isotherms. The maximum degree of recovery (over 96 %) was achieved by passing a solution with a concentration of 11.3 mmol/dm3. Using an array of experimental data, the MLP-3-5-1 neural network was trained. The coefficient of determination R2 = 0.999420 obtained for the training sample characterizes high network performance. Conclusions: The Langmuir equation better describes the process of NH4+ sorption on a fibrous sorbent. It is reasonable to use VION KN-1 at the fine treatment stage. Ammonium ion desorption from the fiber was performed by acid solution. The resulting solutions of ammonium salts can be used as liquid fertilizers. The trained neural networks can be used to predict the degree of recovery of ammonium ions by sorbent VION KN-1.

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