Search Results

You are looking at 1 - 10 of 19 items for :

  • "cation exchange capacity" x
  • Earth and Environmental Sciences x
  • Refine by Access: All Content x
Clear All

Hungarian). MSZ-08-0214-1 . 1978 . Quantitative and Qualitative Determination of Cation Exchange Capacity in Soil . Hungarian Standards Association , Budapest (in Hungarian

Restricted access
Agrokémia és Talajtan
Authors: Barbara Simon, E. Michéli, G. E. van Scoyoc, and et al.

The Typic Haplustalfs soils (Karád and Oltárc) and the Typic Ustochrepts (Gödöllő) are developed on loess, and on aeolian sand parent material, under forest vegetation, resp. The Dystric Ustochrepts (Velem) soil formed on metamorphic schist parent material and had forest vegetation, while the Typic Medisaprists (Zalavár) soil developed on peat parent material and had marsh vegetation.   Based on this study the spatial variability of surface pH samples indicate that the TIM sampling procedure should be improved. Ten to thirty samples must be collected at each site to be able to monitor changes of 0.2 pH units. If only one sample is taken at each site yearly, spatial difference in pH or other parameters are likely to obscure differences which may be occurring over time.  The colloidal composition (organic matter and clay minerals), influenced by parent material, vegetation, and precipitation, showed a close relationship with the acidity factors, such as pH, HAC 1 and EAC 1 values. The pH values were the lowest in the Velem and Oltárc soils where the annual precipitation was the highest (750-800 mm), and in the Karád soil, where the annual precipitation was 650-700 mm. The Gödöllő soil had the highest pH values, probably due to the lowest amount of rainfall (550-600 mm) and the disturbance. The Zalavár soil had fairly high pH throughout the profile probably due to a fluctuating water table.   The HAC 1 and EAC 1 values were the highest in the Velem soil when compared to the other mineral soils.  The pH values were the lowest at this site. The HAC 1 and EAC 1 values were lower in the other three forest soils, at the Karád, Oltárc, and Gödöllő sites. The Zalavár soil had fairly high HAC 1 values in the H3, H4 and H5 horizons, probably due to the very high OM content, which provided a lot of H + ions that can dissociate from the exchange sites.   The E4/E6 ratios were closely related to the decomposition or humification rate in the upper and the subsurface horizons with accumulation of low molecular weight soluble fraction in the deeper horizon.   The mineralogical analysis showed similar compositions for the soils developed on loess (Karád and Oltárc), or aeolian sand (Gödöllő), where the major minerals were vermiculite, mica, kaolinite, and chlorite. A different mineral composition (mica, vermiculite, clintonite, and kaolinite) was observed for the Velem site, where the parent material was metamorphic schist. The four mineral soils are forest soils, with a predominant downward water movement, thus with fairly intensive leaching process. However, there was a distinct difference among the soils formed on loess (Karád and Oltárc), or aeolian sand (Gödöllő), and the soil (Velem) developed on metamorphic schist parent material.  The soils at the Karád, Oltárc, and the Gödöllő sites were less acidified, with higher pH, and lower HAC 1 , and EAC 1 values as compared to the Velem soil, even if the precipitation was very high. The calcareous loess parent material probably compensated for the higher precipitation and the resulting leaching process at the Karád and the Oltárc sites. The Gödöllő soil received a very low amount of precipitation, which resulted in a low degree of weathering, with higher pH, and lower HAC 1 , and EAC 1 values. However, the metamorphic schist parent material probably contributed to a lower pH and lower buffering of the developing soil.   Based on the chemical and physical analyses, we concluded that among the soil forming factors, precipitation and parent material had the greatest influence on the acidity characteristics of the examined soils. The parent material influenced the mineralogy of the developing soil, which then influenced the pH, HAC 1 , EAC 1 , and CEC values of the soil. In order to substantiate these tendencies more samples from a wider array of geological regions are needed.   

Restricted access

et al., 2018). In Europe, C REAMER et al. (2016) noted that soil respiration rate was greatly influenced by soil properties, such as pH, SOM, total nitrogen (TN), and cation exchange capacity (CEC). Temperature and water content were also found to be

Open access
Agrokémia és Talajtan
Authors: G. Gelybó, E. Tóth, C. Farkas, Á. Horel, I. Kása, and Z. Bakacsi

cation exchange capacity . In: Standard Soil Methods for Long-Term Ecological Research, Oxford University Press , New York . 106 – 111 . Rosenzweig

Restricted access

Abstract

Extreme changes of environmental conditions can alter the soil properties and influence the migration ability and bioavailability of pollutants. Elucidation of the effects of the extreme weather conditions, such as sharp temperature change, drought and floods, on the fractionation of radionuclides in different soil types is especially important for adequate risk assessment after radioactive contamination. The effects of short-term and prolonged freezing and soil drought on the geochemical fractionation of americium in two soil types (Fluvisol and Cambisol, classified according to the World Reference Base for Soil Resources/FAO) from Bulgaria were studied. The changes of the physico-chemical forms of 241Am after storage under different conditions were determined by the sequential extraction procedure and gamma-spectrometric measurements. The impact of the sharp temperature decrease and drought on the association of the radionuclide with the various soil phases was considered in terms of the soil characteristics. The results showed that the risk of increased mobility and bioavailability of americium in the loamy-sand soil with acidic pH and very low cation exchange capacity (CEC) exists under the examined extreme environmental conditions. The soil with sand-loam texture tended to immobilize americium after freeze and drought storage.

Restricted access
Central European Geology
Authors: Zsuzsanna Szabó, Nóra Edit Gál, Éva Kun, Teodóra Szőcs, and György Falus

by incorporating cation exchange capacity as modeling input, by refining applied transport parameters, and even extending the approach to 2D and 3D. Estimation of solution conductivity and rock total porosity changes are also useful and expected in

Open access
Agrokémia és Talajtan
Authors: I. Kádár, P. Ragályi, A. Murányi, L. Radimszky, and A. Gajdó

. Rapid method for the determination of cation exchange capacity of calcareous and noncalcareous soils . J. Soil Sci. Food Agric . 15 . 821 – 823 . B uzás , I. (Ed

Restricted access

Kationos felületaktív anyag, a hexadecilpiridinium-klorid (CPC) adszorpcióját vizsgáltuk különböző talajokon, üledékeken és ásványi őrleményeken. Valódi talajokon történő adszorbeálódásáról kevés irodalmi adat található. Célunk volt megha-tározni, hogy mely talajtulajdonságok befolyásolják leginkább a tenzid megkötődé-sét.

A minták ásványos összetételének meghatározása röntgen-pordiffrakcióval (XRD) történt. Ez alapján hat csoportra tudtuk elkülöníteni: 1. Szmektites (kis rétegtöltésű montmorillonitos) talajok; 2. Vermikulitos talajok; 3. Szmektitet is tartalmazó illites minták; 4. Klorit/vermikulit tartalmú talajok; 5. Illit és klorit tartalmú talajok; 6. Nagy kvarctartalmú minták.

A minták felületaktív anyaggal történő kezelése az ún. „elárasztásos módszerrel” (static equilibrium experiments) valósult meg.

A CPC oldat koncentrációjának függvényében ábrázoltuk a minták által adszor-beált tenzidmennyiségét, majd a mérési pontokra Langmuir-típusú izotermát illesz-tettünk. Az adszorpciós izotermák segítségével meghatároztuk a vizsgált adszorbensek hidrofóbizálásához szükséges fajlagos tenzidmennyiségeket, amely mellett feltételeztük, hogy a talajszemcsék felületén monomolekuláris tenzidborítottság alakul ki. Az illesztett görbe telítődő jelleget mutat és első szakasza nagy affinitású H-típusra utal. Logaritmikus skálán ábrázoltuk a tenzidadszorpciós értékeket és megállapítottuk, hogy az egyes minták monomolekuláris rétegborítottságához szükséges tenzidmennyiségek mintánként általában szignifikánsan eltérőek. A fajlagos CPC mennyiségét a nagy agyagtartalmú, szmektites minták esetében találtuk a legnagyobbnak, a kvarchomok mintáét pedig a legkisebbnek.

Vizsgáltuk, hogy a minták mely tulajdonságai állnak kapcsolatban a monomolekuláris telítettségnél adszorbeált fajlagos tenzid mennyiségekkel. Számítottuk továbbá a Pearson-féle korrelációs együtthatókat.

A fajlagos tenzid mennyiségével szoros összefüggést mutatott a higroszkóposság (hy1), az agyagtartalom, a fajlagos felület (BET-felület) és a kationcserélő képesség (T-érték). A CPC adszorpcióját leíró regressziós egyenletek szerint öt paraméter határozza meg a fajlagos tenzid mennyiségét: agyag-, humusz-, mésztartalom, pH(H2O) és a BET-felület.

Restricted access

, J. , Solomon , D. , Kinyangi , J. , Grossman , J. , O’Neill , B. , Skjemstad , J. O. , Thies , J. , Luizao , F. J. , Petersen , J. , Neves. , E. G. 2006 . Black Carbon Increases Cation Exchange Capacity in Soils . Soil

Restricted access

. , S KJEMSTAD , J. O. , T HIES , J. , L UIZÃO , F. J. , P ETERSEN , J. & N EVES , E. G. , 2006 . Black carbon increases cation exchange capacity in soil . Soil Science Society of America Journal . 70 . 1719 – 1730

Restricted access