Wyniki wyszukiwania - Biblioteka Nauki

1

Zmiany zawartości azotanów(V) i (III) w pietruszce naciowej zapakowanej i przechowywanej w atmosferze modyfikowanej

100%

Biegańska-Marecik R. , Walkowiak-Tomczak D. , Radziejewska-Kubzdela E.

Aparatura Badawcza i Dydaktyczna

|

2010

|

tom T. 15, nr 4

131-136

PL

W pracy określono zmiany zawartości azotanów(V) i (III) w pietruszce naciowej zapakowanej i przechowywanej w różnych warunkach atmosfery modyfikowanej. W świeżej pietruszce naciowej zawartość azotanów(V) wynosiła 33,1 mg NaN03/kg. Zastosowanie do pakowania pietruszki atmosfery modyfikowanej o 3% początkowej zawartości tlenu i folii opakowaniowej o przepuszczalności tlenu 1500 cm3/ m2/ 24 h*bar spowodowało istotny wzrost zawartości azotanów(V) w czasie 12 dni przechowywania produktu, do wartości 278 i 310 mg NaN03/kg produktu. W próbach pietruszki naciowej zapakowanych w atmosferze o wysokiej początkowej zawartości tlenu (50 i 80 %), przy zastosowaniu do pakowania folii o przepuszczalności tlenu 60 cm3/ m2/ 24 h*bar odnotowano spadek zawartości azotanów(V) w czasie przechowywania. W żadnej z analizowanych prób nie odnotowano obecności azotanów(lll).

EN

The changes of nitrate and nitrite in leaves parsley packed and stored under modified atmosphere condition was determined. In fresh leaves parsley the content of nitrate was 33.1 mg NaN03/kg. Application of modified atmosphere containing 3% of oxygen and packaging film with oxygen permeability 1500 cm3/ m2/ 24 h*bar to parsley packaging significantly increased the levels of nitrates during 12 days of product storage (to a value of 278 and 310 mg NaN03/kg). The use packaging film with oxygen permeability 60 cm3/ m2/ 24 h*bar and high oxygen atmosphere (50 and 80%) for parsley storage resulted in decrease of nitrate content. In none of the analyzed samples there was no nitrite.

2

THE INFLUENCE OF THE DEACETYLATION DEGREE OF CHITOSAN IN THE FORM OF FLAKES ON THE EFFECTIVENESS OF NITRATES V SORPTION FROM AQUEOUS SOLUTIONS

100%

Jóźwiak T. , Filipkowska U. , Bugajska P. , Kuczajowska-Zadrożna M. , Mielcarek A.

Progress on Chemistry and Application of Chitin and its Derivatives

|

2018

|

tom 23

88 - 96

EN

The influence of the degree of deacetylation of chitosan from the range of DD = 75–90% on the effectiveness of sorption of nitrates from aqueous solutions was investigated. The scope of the research included: determining the effect of pH on the effectiveness of N-NO3 binding on chitosan sorbents and determining the sorption capacity of chitosan sorbents with different degrees of deacetylation after 5, 15, 30 and 60 minutes. The effectiveness of sorption of nitrates on chitosan sorbents increased in the series DD=75% < DD=85% < DD=90%. Regardless of the degree of deacetylation, the sorption effectiveness of nitrates on chitosan was the highest at pH 4. The amount of nitrate-related sorbents was the highest after 30 min of sorption. A process time which was too long resulted in desorption of nitrates. The maximum sorption capacity for chitosan with the degree of deacetylation DD = 75, 85 and 90% was 0.59 mg N-NO3/g, 0.60 mg N-NO3/g and 0.87 mg N-NO3/g, respectively.

3

Jak ograniczyc zawartosc azotanow w warzywach?

100%

Kot M.

Biuletyn Informacyjno-Handlowy. Ośrodek Doradztwa Rolniczego Boguchwała

|

1994

|

nr 02-03

11

4

Selected ionic components of the marine aerosol over the Gulf of Gdańsk

100%

Nadstazik A. , Falkowska L.

Oceanologia

|

2001

|

tom No. 43 (1)

23-37

EN

Aerosol samples were collected in May 1997 at a routine off-shore measurement station in the Gdansk Deep region and at Hel, the latter being a coastal station situated at the tip of the Hel Peninsula. Concentrations of NO3–, Cl–, Na+, Mg2+, K+ and Ca2+ were measured simultaneously at both stations. The sea influences the chemical composition of aerosols in the coastal zone of the Gulf of Gdansk regardless of season, time of day or direction of advection. Sodium chloride was always present in aerosols in the form of large particles originating from seawater. Besides the marine chloride and nitrate, additional amounts of these ions could have been of terrigenous origin. Sodium and chloride concentrations were dominant in the total mass of aerosols at both stations; however, these concentrations were three times higher at the marine station. Similarly, the concentrations of ions originating from seawater, like magnesium and calcium, were, on average, three times higher at the marine station. The chemical composition of aerosols and air over the Gulf of Gdansk was modified through the evaporation of chloride from the marine salt particles in reactions with gaseous nitric and sulphuric acids. A certain deficit of chloride versus sodium ions was noted. At the marine station the Cl–/Na+ ratio reached 0.89 š 0.2, on average, while over the land station it was 0.93 š 0.25, i.e. lower than the seawater standard.

5

The effect of initial concentration of substrates on the kinetics of denitryfication

100%

Waligorska M. , Domka F.

Polish Journal of Environmental Studies

|

1994

|

tom 03

|

nr 1

EN

In this paper we present the results of studies on the influence of an initial substrate concentration (NO3-, sodium lactate) on the kinetics of denitrification. We have found that the optimum rates of the process are obtained at 37°C for the nutrient medium containing sodium lactate at a concentration of 2.52 g/dm3, and nitrate nitrogen 1,4 g/dm3.

6

Produkty przejściowe rozkładu termicznego Cr(NO3)3·9H2O

88%

Łabuś S.

Materiały Ceramiczne

|

2008

|

tom R. 60, nr 3

100-105

PL

Badano stechiometrię produktów przejściowych tworzących się podczas rozkładu termicznego dziewięciowodnego azotanu(V) chromu(lll), prowadzonego z szybkością 0,1°C-min·-1 w zakresie temperatur 20-300°C, w atmosferze powietrza. W badaniach wykorzystano pomiary TGA, EGA, spektrofotometrię, potencjometrię oraz tradycyjne metody analityczne. Stwierdzono, że w skład przejściowych produktów rozkładu wchodzą jony Cr(VI) i Cr(lll), grupy azotanowe (NO3-) i hydroksylowe (OH-), jony tlenkowe (O2-) oraz cząsteczki wody. Zaproponowano metodykę umożliwiającą ilościowe oznaczenie składu stechiometrycznego produktów rozkładu w badanym zakresie temperatur.

EN

The stoichiometry of chromium(lll) nitrate nonahydrate (CNN) thermal decomposition intermediate products were investigated. Substrate decomposition were done at the temperature range 20 - 300°C in dry synthetic air flow with the heating rate 0,1°C·min-1. During investigation the different analytical technics, like thermogravimetry (TGA-DTA), evolving gas analysis (EGA), spectrofotometry, potentiometry, as well as traditonaly analytical methods were appllied. It was found, that intermediate product of CNN thermal decomposition contain Cr(VI) and Cr(lll) ions, nitrate (NO3-) and hydroxyl (O2-) and water molecules. The method enabled quantitative determination of stoichiometry the thermal decomposed products at investigated temperature range was proposed.

7

Effect of Different Plant Monocultures on Nitrogen Removal Performance in Wetland Microcosms

88%

Wang R. , Quan Y. , Zheng S. , Zhang X.

Journal of Ecological Engineering

|

2022

|

tom Vol. 23, nr 9

241--249

EN

This study investigated the nitrogen removal performance in wetland microcosms individually planted with different plant monocultures, including emergent, free-floating and submerged plants during ammonia removals, or large- and small-leaf free-floating plants during nitrate removal. For ammonia-dominated wastewater, both emergent (common reed) and free-floating (water hyacinth) plants in wetland microcosms achieved higher total nitrogen removals than a submerged plant (eelgrass) that significantly improved the microbial nitrifying performance. For nitrate-dominated wastewater, efficient nitrate removals in wetland microcosms planted with free-floating plant were achieved by both a full cover of water surface and the concentration of organic oxygen-consuming substances, which resulted in low dissolved oxygen levels and boosted microbial denitrification in wetland microcosms. FWS-CW developers and managers should thus pay close attention to the selection of wetland plant types and optimize their design to achieve optimum nitrogen removal performance.

8

Assessment of water pollution by nitrates in the Middle Odra Basin

88%

Kolanek A. , Korol R. , Strońska M. , Szyjkowska U. , Kolanek A. , Korol R. , Strońska M. , Szyjkowska U.

|

nr 11

9

Applying of water quality indices methods for assessment of 9-Nissan Water Treatment Plant

88%

Abdul-Hameed H. M.

Journal of Water and Land Development

|

2020

|

tom no. 47

25--29

EN

In this research different methods for measuring water quality indices were conducted to investigate the performance of the newly designed, constructed and operated 9-Nissan water treatment plant, Iraq. Data gathering and implementation took place throughout winter and summer. Water samples were taken periodically, according to the standard method, the research was carried out by collecting different random samples for eight months (Jun. 2015–Jan. 2016) and measuring (turbidity, total hardness, pH, total dissolved solids, suspended solids, Cl–, Mg2+, Fe2+,NO3–, NH3+) for each sample. Five different approaches and methodologies of calculating the water index were applied. The results revealed that the Water Quality Indices varied from 70.55 to 88.24, when applying Canadian Council of Ministers of the Environment Water Quality Index (CCMEWQI) and British Columbia water quality index (BCWQI) geometric weighted mean respectively. All the results, from the five approaches indicated good water quality, multiple regression analyses were conducted for turbidity, total hardness and suspended solids, they found that these parameters are strongly related to each other and to other parameters.

10

Analiza zanieczyszczenia związkami azotowymi wody ujęcia „Grotowice”

88%

Landwójtowicz A.

Zeszyty Naukowe. Mechanika / Politechnika Opolska

|

2013

|

tom z. 102

91-94

EN

The following article analyzes water quality in “Grotowice” water intake, especially in terms of the presence of nitrates. The analysis of changes in nitrates levels in the period from 2000 to 2012 has shown a positive and lasting trend of decreasing of their content since 2004. Nevertheless, the problem of contamination with nitrogenous compounds for the analyzed site is still valid. The most important of them is the need for a buffer zone for each intake well.

11

Isotopic studies of nitrates – a short review

88%

Gebus B. , Hałas S.

|

tom 70

EN

Nitrogen is an essential element for life. One of its available forms are nitrates - the compounds playing a key role in the biogeochemical N cycle. However, excessive amounts of nitrates may be harmful to organisms and the environment, therefore in recent years the emphasis is on continuous monitoring of quality of consumed water. Nitrates from different sources have wide, but different ranges δ15N and δ18O. Also researchers observed typical changes in both delta values induced by biological processes and in the case of mixing water with anthropogenic nitrates. This is a reason why the isotopic analysis are often used to identify the source of contamination in a reservoir or to quantitatively describe the processes occurring in an ecosystem.In this review article, we present a model of the global nitrogen cycle, along with the latest data on the disturbances caused by human activity. We describe the processes occurring in the N cycle and biogeochemical mechanisms, which modify the nitrogen isotopic composition in their compounds. We also present a short description of analytical techniques utilized for studying isotopic compositions of nitrates. In addition, we discussed the methods for extraction and preparation of nitrates from freshwater and ocean water, by determining the δ15N, δ18O and δ17O (or Δ17O) values. The final part is a description of applications of developed techniques for environmental research.

12

Removal of Nitrate from Aqueous Solution by Bio-Calcium from Iraqi Eggshells

88%

Al-Agili Z. H.

Journal of Ecological Engineering

|

2023

|

tom Vol. 24, nr 9

10--18

EN

Nitrate contamination of drinking water is one of Iraq’s environmental problems in some of its most vital lands as a result of sewage sedimentation, agricultural fertilizer waste, and remnants of war. Iraqi egg waste (bio-calcium Iraqi eggshells) was tested to remove nitrates, which is considered one of the best investments to achieve industrial sustainability on the one hand and reduce environmental problems on the other. The optimum conditions for removal were pH = 6, 120 min, 0.5 g Iraqi eggshells, and 150 rpm where 95.73% of nitrates were removed by Iraqi eggshells. The equilibrium data analysis determined that the (Langmuir isotherm) model was the best for describing adsorption, while (pseudo-second-order) adsorption kinetics were significantly appropriate for demonstrating nitrate adsorption kinetics, and a statistical model for nitrate removal percentage was developed.

13

Experimental studies on effect of sodium fluoride and nitrate on biochemical parameters in rats

88%

Zabulyte D. , Uleckiene S. , Kalibatas J. , Paltanaviciene A. , Jascaniniene N. , Stosik M.

Bulletin of the Veterinary Institute in Puławy

|

2007

|

tom 51

|

nr 1

EN

The aim of the study was to investigate the effects of sodium fluoride (NaF) and nitrate (NO₃⁻) either administered orally alone or in a combination, on the biochemical parameters of rats. Tests on general toxicity were conducted on the basis of methodical recommendations 408 of the Organisation for Economic Co-operation and Development Guideline for Testing of Chemicals: "Subchronic Oral Toxicity - Rodent: 90-d Study".The following combined effects of the tested chemicals were predominantly observed: additive, synergistic, and antagonistic. Methaemoglobinaemia was noted in groups given NO₃⁻ or NaF + NO₃⁻ complex.

14

Nitrates [V] in loess soils modified by weather conditions [preliminary data of a model experiment]

88%

Glinski P. , Stepniewska Z. , Kotowska U. , Borkowska A.

International Agrophysics

|

2007

|

tom 21

|

nr 1

15

Levels of residual nitrates and nitrites in milk in 1996

88%

Baranova M. , Burdova O. , Mal'a P. , Zezula I.

Bulletin of the Veterinary Institute in Puławy

|

1998

|

tom 42

|

nr 2

EN

Levels of nitrates and nitrites were observed in pooled samples of milk from selected suppliers of the Košice dairy, and in dairy treated milk during certain months of the year. The average value of nitrates in examined (432) pooled samples of milk ranged from 1.84 to 4.58 mg of NaNO₃.1⁻¹, and in dairy-treated milk (72 samples), from 2.33 to 6.23 mg of NaNO₃.1⁻¹. In the both cases maximal values of nitrates were observed in April, and minimal values in January. With the exception of one pooled sample, all the examined milk samples complied with the Slovak Codex Alimentarius, where the highest values of nitrates and nitrites in some of the final products are fixed. The average value of nitrites in the examined samples of milk taken during the investigated period, amounted to 0.07 mg of NaNO₂.1⁻¹.

16

The effect of environment conditions on the level of nitrates and nitrites in various varieties of potato

88%

Miedzobrodzka A. , Cieslik E. , Sikora E. , Leszczynska T.

Polish Journal of Food and Nutrition Sciences

|

1992

|

tom 01

|

nr 4

17

Nutrient losses from manure after application

75%

Shepherd M.

Nawozy i Nawożenie

|

2001

|

tom 03

|

nr 1[06]

18

Effect of temperature in removing of anions in solution on biochar using Zea mays stalks as a precursor

75%

Villabona-Ortiz Á. , Tejada-Tovar C. , Ortega-Toro R.

Journal of Water and Land Development

|

2021

|

tom no. 50

64--68

EN

Biochar was prepared from corn (Zea mays) stalks and impregnated with sulfuric acid. The biomass was impregnated for 24 h with a 50% solution of H2SO4 with impregnation ratios 1:2 (B 1:2) and 1:3 p/v (B 1:3); then, it was carbonized in a muffle furnace at 520°C for 30 min with a 10°C per min ramp. The adsorption capacity to remove anions (nitrate, sulfate, and phosphate) in an aqueous solution was evaluated by varying the temperature. The adsorption mechanism was studied by determining the thermodynamic parameters: Gibbs free energy (ΔGº), enthalpy (ΔHº) and entropy (ΔSº) standard. The biochars were characterized by Scanning Electron Microscopy-Energy Dispersive X-Ray Spectroscopy (SEM-EDS) analysis and were found to exhibit a heterogeneous surface and porous nature, with C, O, S, and Si. The experiments in the batch system showed the best performance of B 1: 2 in the removal of the three anions occurred at 303 K, while B 1: 3 had the best performance at 298 K. From the thermodynamic parameters, it was found that the removal processes are endothermic, their mechanism is by chemisorption. It is concluded that synthesized biochar is an excellent alternative to removing nutrient anions present in the solution.

19

Assessment of the Feasibility of Modified Chitosan Beads for the Adsorption of Nitrate from an Aqueous Solution

75%

Jamka Z. N. , Mohammed W. T.

Journal of Ecological Engineering

|

2023

|

tom Vol. 24, nr 2

265--278

EN

The objective of the current work was to investigate the effectiveness and mechanism of nitrate removal from an aqueous solution by adsorption using metal (Zr4+)loaded chitosan and Bentonite beads (Cs-Bn-Zr). The study was carried out in a batch system, and the effect of the critical factors on the adsorption performance, such as contact time, initial nitrate anion concentration, and adsorbent dosage, were investigated. In addition, the adsorption equilibrium models of the Langmuir, Freundlich, and Temkin isotherms were evaluated. The modified adsorbent was characterized by Fourier transform infrared spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), and analysis with an energy-dispersive X-ray analyzer (EDX). The results demonstrated that at 0.2 g of CS-Bn-Zr adsorbent with an initial concentration of 50 mg/l and a contact time of 120 minutes, the maximum removal of nitrate ions was found to be 97.28%. The result demonstrated that the maximum adsorption capacity of nitrite ions on the manufactured bead was 110.46 mg/g. The Freundlich model was shown to be the most effective for the adsorbate of nitrate. The pseudo–first-order model fits the adsorption kinetic data well.

20

Plant peroxidases and nitrogen metabolism: interactions with nitrates and nitrites

75%

Minibayeva F. , Galeeva E. , Gurjanov O. , Viktorova L.

BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology

|

2013

|

tom 94

|

nr 2