Wyniki wyszukiwania - Biblioteka Nauki

1

Soil Redox Potential and its Impact on Microorganisms and Plants of Wetlands

100%

Tokarz E. , Urban D.

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tom Vol. 16, nr 3

20--30

EN

Although peatlands cover only 3% of the Earth’s surface, they constitute a huge reservoir of carbon. It is estimated that they accumulate one third of carbon contained in all types of soils worldwide. Therefore, knowledge of the physical, chemical, and biological properties of peat is important for prevention of peat degradation and release of carbon stored as CO2 into the atmosphere. In organic soils, water plays a very important role as a protective factor against mineralisation of organic matter. Therefore, organic soils are characterised by high specificity and dissimilarity from mineral soils. The hydrological factor induces a variety of changes in the physical and chemical properties, e.g. low redox potential or low oxygen content in soil pores. Many soil processes are determined by the soil oxygenation status, which can be measured with various indicators as well as direct and indirect measurements. One of the indirect methods is measurement of the redox potential. The oxidation-reduction potential (redox potential or Eh) is a measure of the ratio of oxidised to reduced forms in a solution. This parameter is inextricably linked to oxygen supply and the processes of consumption thereof by microorganisms and plant roots. Therefore, the redox potential is used as an indicator of the oxygenation status and the content of biogenic forms and toxins in the soil environment and sediments. In the case of submerged soils, penetration of atmospheric oxygen into the soil is limited due to low rates of oxygen diffusion and, hence, low redox potential, which inhibits plant growth through inhibition of respiration and production of toxins in reducing conditions. The aim of this article is (1) to the show soil-plant-soil microorganism interactions taking place on peatbogs in the context of redox potential, (2) to investigate the responses of plants and soil microorganisms to the changing redox potential, and (3) to demonstrate the mechanisms of plant adaptation to the reducing conditions prevailing in peatbogs.

2

Impact of ovalbumin on pyrite flotation in the absence and presence of metal ions

88%

Guler T. , Sahbudak K. , Akdemir U. , Cetinkaya S.

Physicochemical Problems of Mineral Processing

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2014

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tom Vol. 50, iss. 1

31--40

EN

Recovery of gangue pyrite and its accidental activation are vital issues in flotation of complex sulfide ores. This work was performed by cyclic voltammetry (CV) and flotation tests to elucidate applicability of ovalbumin (OVA) as depressant for pyrite. The synergetic effect of metal ions in addition to its possible use in case of accidental activation by metal ions. CV tests stated that OVA adsorbed irreversibly on pyrite, and restricted electron transfer up to moderately oxidizing potentials due to electrostatic interaction together with weak hydrophobic interactions. At highly oxidizing potentials, adsorption occurred through electrochemical mechanisms through formation of metal-OVA chelates. Rate of pyrite depression with OVA was found to be potential dependent reaching its peak point around moderately oxidizing potentials both in absence and presence of metal ions. Electrochemically active metals display synergetic effect with OVA on pyrite depression, whereas noble metals activate pyrite and reduced depressing potency of OVA.

3

Redox Potential in Soil as Affected by Many Yeras of Fertilization

88%

Łabuda S. , Mazurkiewicz I. , Maćkowiak C.

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tom Vol. 9, nr 4

419-429

EN

The aim of investigation was to determine the effect of many years application of organic matter and nitrogen fertilization on the redox potential as well as of soil suppleness on reduction in laboratory conditions. The treatments in the field experiment were 2 crop rotations, 3 level of farmyard manure application of 0,40 and 80Mg/ha for 4 years, and 4 levels of nitrogen fertilization with the rate of 0, 40, 80, and 120 kg/ha for year. In the soil samples from the field experiment the following parameters were determined: organic - C, total - N, available - P, sulfate - S, mobile - Fe and active - Mn. In the soil-water suspension prepared as l: l soil to water ratio and kept at 25°C the redox potential (Eh) and reaction (PH) after the 1, 24, 48, 96, 168 and 336 hours were measured. The organic matter application and nitrogen fertilization had only a little influence on the values of redox potential in the soil-water suspension. The investigated soil had a low suppleness on reduction due to the experimental treatments applied.

PL

Celem badań było określenie wpływu wieloletniego stosowania substancji organicznej i nawożenia azotem na potencjał redoks oraz podatność gleby na redukcję w warunkach laboratoryjnych. Czynnikami w doświadczeniu polowym były 2 zmianowania, 3 poziomy stosowania obornika w ilości O, 40 i 80 Mg/ha co 4 lata i 4 poziomy dawek azotu O, 40, 80 i 120 kg/ha. W próbkach glebowych z doświadczenia polowego oznaczono C - organiczny, N - ogólny, P - przyswajalny, S - siarczanową, Fe - mobilne i Mn - aktywny. W zawiesinie glebowej w stosunku gleba-woda jak I : I przy temperaturze 25°C mierzono potencjał redoks (Eh) i odczyn (PH) w kolejnych terminach po 1, 24, 48, 96, 168 i 336 godzinach. Wieloletnie stosowanie substancji organicznej i nawożenie azotem miało mały wpływ na wartości potencjału redoks i wodnej zawiesinie glebowej, a badana gleba miała małą podatność na redukcję pod wpływem zastosowanych czynników doświadczalnych.

4

Properties of surface of bottom sediments in the coastal zone of the Gulf of Gdańsk (1994-1995)

75%

Dubrawski R. , Witkowska K. , Kula A.

Oceanological Studies

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1998

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tom Vol. 27, No. 4

23-47

EN

Results of chemical and granulometric investigations of bottom surface sediments of the near-shore zone - beach and shallow water zone - carried out along cross-shore profiles in the Gulf of Gdansk in the period 1994-1996 are presented. Organic matter, total phosphorus and nitrogen, and carbonate (beach and dune) contents, also pH and the reducing-oxidising potential (Eh), as well as granulo-metric composition of the sediments were determined. The seasonal and spatial changes in sediment composition, relationships between the components, the rate of self-purification and the influence of factors shaping the properties of sediments were defined. It has been found that the sediment environment of the Gulf of Gdansk is in poor condition and that its further degradation is likely to happen.

5

Pomiar potencjału Redox w procesie denitryfikacji w oczyszczalnin ścieków

75%

Polok A.

Forum Eksploatatora

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2003

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tom Nr 1 (10)

12-15

6

Pomiar wartości potencjału redox

75%

Suchocki K.

Forum Eksploatatora

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2003

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tom Nr 4 (13)

8-10

7

Dezynfekcja wody basenowej metodą ozonowania

75%

Dmochowski D. , Wojtkowska M.

Chemistry-Didactics-Ecology-Metrology

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2001

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tom R. 6, NR 1-2

27--29

PL

W uzdatnianiu wody basenowej stosowane są różne technologie z wykorzystaniem szeregu utleniaczy chemicznych. Skuteczność stosowanych metod zależy od wartości potencjału redoks wykorzystanych utleniaczy. Ozon (O3) jest utleniaczem o wysokim potencjale redoks (2,07V). W technologii uzdatniania wody metodą ozonowania uzyskuje się poprawę właściwości organoleptycznych, usunięcie barwników i wirusów, utlenianie materii organicznej i mikrozanieczyszczeń.

EN

Different production technologies with a lot of chemical oxidizing agents are used in the treatment of water in swimming pools. The method efficiency depends on the oxidant redox potential. Ozone (O3) has a high redox potential (2.07V). Ozonization of water improves its organoleptic proprieties and removes its different pollutants.

8

Analiza N2O i CO2 wydzielanych z gleby lessowej po wprowadzeniu ściekow miejskich

75%

Stepniewska Z. , Ostrowska A. , Pasztelan M. , Kotowska U.

Acta Agrophysica

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2001

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tom 57

9

How artificial aeration improved sewage treatment of an integrated vertical-flow constructed wetland

75%

Tao M. , He F. , Xu D. , Li M. , Wu Z.

Polish Journal of Environmental Studies

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2010

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tom 19

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nr 1

183-191

EN

Artificial aeration was added to an integrated vertical-flow constructed wetland (called aerated IVCW hereafter) for improving water purification performance. The results showed that both oxygen levels and aerobic zones were increased in the wetland substrates. The electric potential (Eh) profiling demonstrated that artificial aeration maintained the pattern of sequential oxic-anoxic-oxic redox zones within the aerated IVCW chambers in winter, while only two oxic-anoxic zones were present inside the non-aerated IVCW in the cold seasons. The nitrification/denitrification processes and organic matter decomposition were enhanced by artificial aeration since the removal efficiency of NH₄⁺-N and BOD₅ were significantly improved in all seasons, particularly in winter. It seemed that artificial aeration could compensate for the absence of plant-mediated oxygen supply, though the low temperatures and plant dieback still affected the removal efficiency of COD and TN in the winter. Eight hours of artificial aeration per day was sufficient to eliminate the significant accumulation of NO₃⁻-N previously observed in the effluent from continuously aerated subsurface-flow constructed wetlands. These results suggest that the aerated IVCW could treat domestic sewage more efficiently, especially in winter.

10

N2O emission and sorption in relation to soil dehydrogenase activity and redox potential

75%

Wlodarczyk T. , Stepniewski W. , Brzezinska M. , Kotowska U.

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nr 3

11

Pomiar potencjału redoks - czy warto go zastosowac?

63%

Kita T. , Kita M.

Forum Eksploatatora

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2001

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tom Nr 1 (2)

13-14

12

Action mechanisms of antioxidant and prooxidants properties of flavonoids as model for understanding the oxygen metabolism

63%

Espindola C.

BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology

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2013

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tom 94

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nr 2

13

Trochę teorii na temat pomiaru potencjału redoks

63%

Kalinowska E.

Forum Eksploatatora

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2003

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tom Nr 3 (12)

9-10

14

Developmental changes in the levels and redox potentials of main hemolymph thiols/disulfides in the Jamaican field cricket Gryllus assimilis

63%

Sadowska-Bartosz I. , Furmaniak P. , Bieszczad-Bedrejczuk E. , Bartosz G. , Głowacki R.

Acta Biochimica Polonica

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2017

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tom 64

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nr 3

503-506

EN

Main thiols and disulfides were determined in the hemolymph of the Jamaican field cricket Gryllus assimilis at various developmental stages. On the basis of these data, redox potentials of the glutathione, cysteine and homocysteine redox systems were calculated. The concentrations of all thiols studied decreased during development (at a stage of 6 molts) with respect to young crickets, and increased again in adult insects. Redox potentials of the glutathione and cysteine systems increased from values of -131.0±5.6 mV and -86.9±17.1 mV, respectively in young crickets to -58.0±3.6 mV and -36.1±4.2 mV, respectively, at the stage of 6 molts and decreased to values of -110.4±24.8 mV and -66.3±12.2 mV, respectively, in adult insects. Redox potentials of the glutathione and cysteine systems in the hemolymph of young and adult insects were similar to those reported for human plasma.

15

Potencjał redox jako istotny parametr kontroli technologicznych procesów produkcji szkieł użytkowych. Cz. II - Metody określania potencjału redox.

63%

Zawiła J.

Szkło i Ceramika

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2006

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tom R. 57, nr 4

26-29

16

Wpływ czynników technologicznych na potencjał redox stopu szklanego

63%

Zawiła J.

Prace Instytutu Szkła, Ceramiki, Materiałów Ogniotrwałych i Budowlanych

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2008

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tom R. 1, nr 1

45-57

PL

Omówiono zagadnienia związane z rolą, jaką odgrywa stan redox w procesie topienia szkieł użytkowych. Przedstawiono pojęcie i najważniejsze reakcje redox zachodzące w trakcie topienia składników zestawu, omówiono także wpływ niektórych czynników na wartość potencjału redox. Szczególny nacisk położono na: wpływ składu chemicznego zestawu, skład atmosfery nad lustrem szkła, dodatek stłuczki szklanej oraz zanieczyszczeń organicznych w niej zawartych.

EN

There have been described problems connected with function of the redox-state in the melting process of the commercial glasses. Definition and the most important redox-reactions occurring during melting process of glass batch components have been presented as well as influence of some essential factors on the redox-potential values. Especially, attention has been devoted the problems connected with influence of such factors as chemical composition of glass batch, composition of gas atmosphere above the surface of the melt, application and organic contaminations of the cullet.

17

Badania potencjału redoks na przykładzie sudeckich wód leczniczych

63%

Dobrzyński D.

Przegląd Geologiczny

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2010

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tom Vol. 58, nr 1

46-53

EN

In Poland, the redox potential (EH) is seldomly measured in groundwater. Since the year 2006 determination of redox potential is required for documenting properties of curative mineral waters. Investigations of redox conditions in groundwater need both proper measurement and interpretation. In the paper, crucial questions of: 1) redox equilibrium in groundwater, 2) field measurement, 3) correction methods, and 4) EH interpretation are presented. Some aspects of applying the redox potential for interpreting groundwater chemistry and using geochemical modelling are illustrated by hydrochemical data of curative waters from spas in the Sudetes Mts., SW Poland. Main reasons of the common redox non-equilibrium found in groundwater are co-existence of numerous aqueous redox pairs and usually non-equilibrium in particular redox pairs. Redox determinations have to be done in the field, and require extreme cleanness and precision, e.g., measuring without contact with the atmospheric air. Field measurements must be corrected to the standard hydrogen electrode, considering: type of reference electrode, concentration of electrode filling solution, type of standard redox solution, and water temperature. The redox potential has been measured in water at first from all the Sudetic spas, totally in 33 water intakes. In curative waters from the Sudetes corrected EH ranges between –159 mV and +343 mV. Usually, thermal waters show lower EH values than cold, CO2-rich waters. The lowest redox potential was found in the hottest thermal waters, i.e., in water from Zdzisław intake (in Lądek Zdrój) and C-2 intake (in Cieplice Śląskie Zdrój). Generally, the higher the pH, the lower the EH in groundwater. Methods of geochemical modelling, which are often and often applied in groundwater research, also require the EH determination. Information about EH are used in the calculation of speciation models of water, and affect the results of whole geochemical modelling as well as evaluations of the saturation state. The speciation-solubility modelling for the Sudetic curative waters, presented in the paper, shows that the proper correction of field EH measurement determines the quality of calculations. Improperly corrected EH values might lead to species activity errors, even up to several order of magnitudes, and erroneous interpretation of the mineral phases stability in the hydrogeochemical system.

18

The influence of the redox potential of the medium on the growth of some Chlorophyceae

63%

Guminski S. , Jurajda K. , Tatkowska E.

Oceanologia

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1983

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tom 17

19

Anaerobic biological degradation of carbamazepine at environmental concentrations

63%

König A. , Sorgler Y. , Jekel M.

Czasopismo Techniczne. Środowisko

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2016

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tom Y. 113, iss. 1-Ś

45--54

EN

A removal of the antiepileptic drug carbamazepine is frequently observed under anaerobic redox conditions at managed aquifer recharge sites. The biological influence on this effect is widely unknown and therefore it is the focus of this study. Anaerobic degradation batch tests and long-term soil column experiments, conducted within this study, suggest a removal of 2 to 50% induced by microbiological processes. Transformation products and their molecular structures are suggested – one of them is clearly identified as 10,11-dihydro-carbamazepine. This study provides a deeper understanding regarding the biotic reduction of carbamazepine.

PL

Eliminacja leku padaczkowego karbamazepiny jest często obserwowana podczas sztucznego wzbogacania wόd gruntowych w warunkach beztlenowych. W poniższym artykule przedstawiono badania dotyczące dotychczas niedostatecznie zrozumiałego wpływu faktorόw biologicznych na te zjawisko. Przeprowadzone testy naczyniowe (testy batch) w warunkach beztlenowych i testy ciągłe z kolumnami piaskowymi pokazały znaczną eliminację karbamazepiny spowodowanej przez procesy mikrobiologiczne w wysokości 2 do 50%. W artykule zasugerowano produkty transformacji karbamazepiny i ich struktury molekularne – jednoznacznie zidentyfikowana zostala 10,11-dihydro-karbamezepina. Przedstawione badania umożliwiają lepsze zrozumienie biotycznego rozkładu karbamazepiny.

20

Denitrification rate in soils as affect by their redox conditions

63%

Stępniewska Z. , Bennicelli R. P. , Weiss U. , Włodarczyk T. , Stahr K.

Journal of Water and Land Development

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2000

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tom no. 4

163-173

EN

The aim of the study was to investigate the influence of soil redox resistance on denitrification rate in soil material of 9 profiles from Poland and Germany. The soil samples from particular horizons were incubated under water saturation, in closed bottles, in an atmosphere of gaseous nitrogen containing 3 % acetylene at a temperature of 20°C for 5 days. The values of redox potential, pH, and the evolution of carbon dioxide and nitrous oxide were measured after 12, 24, 48, and 120 hours. The rate of nitrous oxide evolution in relation to native carbon mineralization, redox potential and soil reaction is discussed. Denitrification rate showed maximum at pH 6.3-7.3 and Eh 150-300 mV. It was positively correlated with redox resistance (t400).

PL

Badania emisji podtlenku azotu w agrocenozach wykazały, że w zależności od warunków aeracyjnych, gleby mogą być zarówno emiterem jak i sorberem N2O. Krytyczne wartości potencjału redoks, przy których następuje absorpcja i wydzielanie N2O, mieszczą się w zakresie od 250 mV (przy pH 6.0-8.5) do 300 mV (przy pH 5). Doniesienia literaturowe natomiast wskazują na szeroki zakres wartości Eh od +400 mV do +100 mV występujący podczas denitryfikacji. Jedną z propozycji wyrażenia odporności oksydoredukcujnej gleb jest wskaźnik t400, charakteryzujący zdolność buforującą gleb. Miarą jego jest czas, w którym następuje obniżenie wartości Eh gleb do 400mV, która charakteryzuje redukcję azotanów. Celem pracy było zbadanie wpływu odporności oksydoredukcyjnej gleb na szybkość denitryfikacji w 9 glebach z Polski i Niemiec. Próbki glebowe z poszczególnych poziomów próchnicznych były inkubowane w stanie wysycenia wodą, w zamkniętych naczyniach, w atmosferze gazowego azotu, zawierającej 3% acetylenu w temperaturze 20°C przez 5 dni. Wartości potencjału redoks, pH oraz stężenia powstającego CO2 i N2O były oznaczane po upływie 12, 24, 48 i 120 godzin inkubacji. Szybkość wydzielanego podtlenku azotu jest analizowana w odniesieniu do mineralizacji węgla organicznego, potencjału redoks oraz pH. Wykazano, że proces denitryfikacji osiągał maksimum szybkości przy pH 6,3-7,3 i Eh 150-300mV. Najwyższe kumulatywne stężenie podtlenku azotu dochodziło do 8 mg·kg-¹ po upływie 5 dni inkubacji przy pH 7, podczas gdy w przedziale pH 3-6.5 wartości stężeń były ponad dwukrotnie niższe (3 mg·kg-¹) . Wykazano istnienie dodatniej korelacji (R² = 0,49) pomiędzy szybkością denitryfikacji a odpornością oksydoredukcyjną (t400). Kiedy wartość t400 nie przekracza 2, wówczas tempo denitryfikacji spada poniżej 1,2 mg·kg-¹ ·dzień-¹.