Grzegorz Jozefaciuk

• Polish Academy of Sciences

Nitrogen adsorption isotherms, along with the BET model for interpretation, are recommended for estimating biochar surface area. The frequently measured small surface areas of biochars contrast with their high sorption and cation exchange capacities. We hypothesised that water adsorption provides a better tool for estimating the surface area of bio...

Biochar has great potential as a soil conditioner and as a carrier of beneficial microorganisms that support the removal of pollutants, influence the circulation of nutrients, and support plant growth. This review summarizes and discusses factors shaping the physicochemical properties of biochar, including feedstock, pyrolysis conditions, and accom...

Knowledge of the effects of different organic species on soil structure and strength is gained mostly from experiments on natural soils amended with organic substances of various particle sizes, pH, ionic composition, and inorganic impurities. It greatly diversifies the experimental results and shadows individual effects of organic amendments. Ther...

Knowledge on the effects of minerals on soil water stability and wettability is mostly gained from experiments on natural soils of different mineral composition. To gain a “clearer” picture, the water stability and wettability of artificial aggregates composed of soil silt and various proportions of pure minerals: kaolinite, montmorillonite, illite...

Chitosan is becoming increasingly applied in agriculture, mostly as a powder, however little is known about its effect on soil mechanical properties. Uniaxial compression test was performed for cylindrical soil aggregates prepared from four soils of various properties (very acidic Podzol, acidic Arenosol, neutral Fluvisol and alkaline Umbrisol) con...

Chitosan has become increasingly applied in agriculture worldwide, thus entering the soil environment. We hypothesized that chitosan should affect the water stability of soil. Since this problem has not been studied to date, we examined, for the first time, the influence of chitosan on the water stability and wettability of soil aggregates. The agg...

Structure and strength are responsible for soil physical properties. This paper determines in a uniaxial compression test the strength of artificial soils containing different proportions of various clay-size minerals (cementing agents) and silt-size feldspar/quartz (skeletal particles). A novel empirical model relating the maximum stress and the Y...

Wood pellets are an important source of renewable energy. Their mechanical strength is a crucial property. In this study, the tensile strength of pellets made from oak, pine, and birch sawdust with moisture contents of 8% and 20% compacted at 60 and 120 MPa was determined in a diametral compression test. The highest tensile strength was noted for o...

Thousands of tons of zeolitic materials are used yearly as soil conditioners and components of slow-release fertilizers. A positive influence of application of zeolites on plant growth has been frequently observed. Because zeolites have extremely large cation exchange capacity, surface area, porosity and water holding capacity, a paradigm has arous...

Soil strength is an influential property in determining agricultural and geotechnical outcomes. In uniaxial compression test the strength of artificial aggregates containing different proportions of kaolinite (cementing agent) and feldspar (skeletal particles) was determined in uniaxial compression test, and empirical model of aggregates breakage w...

One of the ways to recycle millions of tons of fly ash and chitin wastes produced yearly is their utilization as low-cost sorbents, mainly for heavy metal cations and organic substances. To improve their sorption efficiency, fly ashes have been thermally activated or modified by chitosan. We aimed to deeply characterize the physicochemical properti...

Calcium phosphates, due to their similarity to the inorganic fraction of mineralized tissues, are of great importance in treatment of bone defects. In order to improve the biological activity of hydroxyapatite (HAP), its fluoride-substituted modification (FAP) was synthesized using the sol-gel method and calcined at three different temperatures in...

3D virtual network was numerically constructed from particles of various sizes and the drainage process was simulated. The resulting moisture retention curves suggested that the sample geometry affects the drainage. This unexpected result was confirmed experimentally for water retention curves of sandy and loamy soil samples differing only in air a...

Existing methods for estimation of water stability of aggregates suffer from intrinsic uncertainties and are not more than semi-quantitative. New method for quantitative measurement of aggregate destruction rate in water was developed basing on monitoring of air bubbling after aggregate immersion by recording a decrease in buoyancy of the aggregate...

Zeolites, naturally possessing a high negative surface charge and large specific surface, are used in agriculture as cationic fertilizers, water holders, heavy metals, and organic pollutants sorbents. Since some nutrients occur in anionic forms, there is a need to modify the zeolite surface to hold anions. In this study, hydrogen (hydrochloric acid...

The effects of 0 (control), 1, 4 and 8 t ha ⁻¹ doses of natural clinoptilolite on the yield and quality of oat were evaluated. The experiment was carried out in a triplicate split-plot system on brown pseudopodzolic soil, with N fertilization applied on all plots. For comparison, standard NPK fertilization was applied on extra plots. As compared to...

The yield potential of 60 spring barley varieties was examined under controlled drought and natural conditions in the years 2011–2013. The studied varieties were genotyped with the 1536‐SNP barley oligonucleotide assay. In experiments with controlled drought conditions, the grain yield, 1,000‐grain weight, number of productive tillers and length of...

The possibility of detecting low levels of soil pollution by petroleum fuel using an electronic nose (e-nose) was studied. An attempt to distinguish between pollution caused by petrol and diesel oil, and its relation to the time elapsed since the pollution event was simultaneously performed. Ten arable soils, belonging to various soil groups from t...

Zeolites have an extremely large surface area and porosity and are frequently applied to soils to increase their sorption properties. However, behaviour of the surface properties of zeolite‐amended soil has not been studied in detail. Seven mineral soils were mixed with various amounts of a zeolitic tuff and subjected to three cycles of wetting–dry...

The microstructure of concretes containing ceramic sanitary ware waste and granite aggregates was studied using scanning electron microscopy, mercury intrusion porosimetry and computer microtomography, before and after cyclic heating of the concretes to 1000 °C. All methods showed an increase in porosities in the concretes after heating. The propos...

It is widely believed that pectin are responsible for the vast majority of cation binding positions in the root cell walls. To estimate the role of particular kinds of pectin, we studied the cell wall material isolated from the roots of monocots (wheat and rye) and dicots (clover and lupine) before and after removal of different fractions of solubl...

We aimed to assess role of cell walls in formation of cation exchange capacity, surface charge, surface acidity, specific surface, water adsorption energy and surface charge density of plant roots, and to find the input of the cell wall pectins to the above properties. Whole roots, isolated cell walls and the residue after the extraction of pectins...

Lightweight aggregates (LWAs) made by sintering beidellitic clay deposits at high temperatures, with and without the addition of spent zeolitic sorbents (clinoptilolitic tuff and Na-P1 made from fly ash) containing diesel oil, were investigated. Mineral composition of the aggregates determined by X-ray diffraction was highly uniformized in respect...

Soil sorptivity is considered a key parameter describing early stages of water (rain) infiltration into a relatively dry soil and it is related to build-up complexity of the capillary system and soil wettability (contact angles of soil pore walls). During the last decade an increasing water repellency of sandy soils under pine forest and grassland...

An admixture of lightweight aggregate substrates (beidellitic clay containing 10 wt % of natural clinoptilolite or Na-P1 zeolite) with used motor oil (1 wt %–8 wt %) caused marked changes in the aggregates’ microstructure, measured by a combination of mercury porosimetry (MIP), microtomography (MT), and scanning electron microscopy. Maximum porosit...

The possibility of distinguishing different soil moisture levels by electronic nose (e-nose) was studied. Ten arable soils of various types were investigated. The measurements were performed for air-dry (AD) soils stored for one year, then moistened to field water capacity and finally dried within a period of 180 days. The volatile fingerprints cha...

Huge amount of information on the plants response to drought is available throughout the literature; however, extremely rare information concerns effects of limited water availability on cation exchange capacity (CEC) and surface acidity of plant roots despite their importance for cations uptake by plants. As it is known, the CEC and acidity of bar...

Most of the information on soil aggregation and porosity comes from studies of natural soil in which the effects of the different constituents that form the structure overlap. The aim of this research was to study the effects of these constituents separately on well-characterized artificial aggregates in order to understand them better. To do this,...

The impact of fertilizer application on soil aggregate stability is of increasing interest to soil scientists. Aggregate water stability depends primarily on soil organic matter. We studied silty loam and loamy sand aggregates from three long-term fertilizer treatments (control, pig manure and NPK) which significantly altered the quantity of organi...

Formation and stability of natural soil aggregates are affected by dozens of different factors and their individual effects are hardly distinguishable. Therefore to observe more clear mechanisms governing their water and mechanical stability, we studied aggregates artificially formed from silt fraction extracted from a loessial soil with various ad...

Amount and properties of roots surface charge are important for nutrient uptake and balance in plants. Roots surface charge markedly varies at different rizosphere conditions (particularly pH and ionic strength), which can markedly alter during vegetation season. Among recently available measuring methods, surface charge-pH dependence of roots (as...

To provide enough space to carry all surface charges responsible for high cation exchange capacity of plant roots, large area of the root specific surface is necessary, however all experimental methods used up to date give too small surface area values. In this paper, we propose to measure the plant roots surface area using water vapor adsorption i...

Huge amount of papers describe plant response to drought, however information on reaction of plant roots cation exchange capacity and surface acidity on draught conditions is up to date lacking. These parameters are important for amount and ratio of cations uptake by plants. Since other stresses induce changes in roots cation exchange capacity and...

Background and Aims: Structure and composition of plant roots surfaces are extremely complicated. Water vapor ad-sorption/desorption isotherm is a powerful tool to characterize such surfaces. The aim of this paper is to present theo-retical approach for calculating roots surface parameters as adsorption energy, distribution of surface adsorption ce...

Throughout the literature the problem of soil wettability is usually associated with hydrophobicity and water repellency. These phenomena occur, as a rule, in soils of high organic matter content. However, mineral soils, usually considered as well wettable, may markedly differ in wettability that may be particularly important for water transport in...

A vast number of environmentally important processes occur on surface of soil solid phase. This surface is extremely complex due to diversified mineral, organic and ionic composition of soil constituents, and it constantly changes under various environmental factors. Soil surface become increasingly used for description and modeling of soil physica...

The size, shape, and continuity of pores in mineral solids greatly influence the behavior of percolating liquids and solids in porous media, which has significant practical environmental implications. In order to expand understanding of these properties in soil minerals, the present study was undertaken to analyze the pore characteristics of benton...

Bentonite, biotite, illite, kaolin, vermiculite and zeolite were acidified or alkalized with hydrochloric acid or sodium hydroxide of concentrations 0.0, 0.1, 1.0 and 5.0 mol dm−3 at a room temperature during two weeks. The treated minerals were transferred to calcium homoionic forms from which aggregates were formed by hand (if possible) and subje...

The plants of winter rye variety Rostockie grown in nutrient solution prepared according to Marschner and Romheld (1983) were stressed at shooting stage with different zinc (ZnCl2) concentrations of 0, 20, 200 and 400mgXdm−3 during 10days at pH=4.5. The control plants were grown continuously at pH=7, without Zn2+. The roots of all plants were titra...

Plant root structure including the pore system is severely injured in Al-toxic environments. Experimental water vapor desorption isotherms estimated using vacuum chamber method were used to characterize micropore build-up of roots of wheat (Lanca) and triticale (Debo) 4-day seedlings and its changes after 24h (8mg dm−3) aluminum stress. The micropo...

We studied pavement seam material. This is the soil substrate in joints of pervious pavements in urban areas. It is mostly 1 cm thick and develops from the original seam filling by depositions of all kinds of urban residues, including anthropogenic organic substances. It was investigated, how this unique form of organic matter influences the filter...

Based on water vapor adsorption–desorption isotherms, the specific surface and its energetic and geometric properties were estimated for twelve profiles of saline soils of different salinity. The contents of clay fraction and organic matter governed the CEC and the surface area of the soils. The contribution of clay fraction to the CEC was over fou...

Measurements were made of the contact angle for glycerol, di-iodomethane and cis-decalin drops settled on the surface of pellets prepared from sodium forms of clay fractions of soils before and after successive removal of organic matter, iron and aluminium. On the basis of contact angles thus measured and a modified Young equation, the dispersive a...

Bentonite, biotite, illite, kaolin, muscovite, vermiculite and zeolite were acidified or alkalized with HCl or NaOH of concentrations 0.0, 0.1, 1.0 and 5.0 mole dm−3 at room temperature for 2 weeks and converted into Ca homoionic forms. Low-temperature nitrogen and room-temperature water-vapor adsorption-desorption isotherms were used to characteri...

The original light-brown sandy seam filling of pavements in urban areas turns dark and changes its properties by the time due to various inputs of urban dust. Deposited Corg inputs do mostly not have natural characteristics but are man-made, e.g., diesel dust. Thus, properties of the seam material are not predictable from experiences with forest or...

Shooting stage roots of cereal plants varying in Al tolerance: rye (Secale L.), triticale (Triticale), barley (Hordeum L.) and four wheat (Triticum L.) varieties grown at pH 7 (controls) and stressed during 10 days at pH 4 with aluminium concentrations ranging from 0 to 40 mg dm–3 were back titrated with NaOH. Back-titration data were used for esti...

Soil-plant-atmosphere system, our living environment. And its components: Soil – microbiologically active, extremely heterogeneous, multiphaseous, multicomponential, polydispersive; Plant – living organism with all its peculiarities; and Atmosphere within which everything is soaked. And extremely complex interrelations between these elements. Peopl...

In this paper, we tried to find interrelations between water retention properties, surface characteristics, and structural features of sandy soils rich in organic matter. Raw humic, epihumic, and endohumic horizons of four acidic sandy forest soils were selected for this study. Specific areas and water adsorption energies were estimated from water...

The application of cyclodextrins in several soil remediation technologies has been increasingly studied, but little is known about their effects on soil physical properties, One of the popular soil remediation additives, randomly methylated beta-cyclodextrin (RAMEB), was found to significantly alter surface and pore properties of soil clay minerals...

Water storage capacity of forest humus layer

Surface areas and energetic properties of the shooting stage roots of rye (Secale L.), triticale (Triticale), barley (Hordeum L.) and four wheat (Triticum L.) varieties were estimated from experimental water vapor adsorption data. Roots stressed during 10 days at pH 4 with aluminium concentrations ranging from 0 to 40 mg dm–3 were studied. Roots gr...

Surface-micropore properties of the clay fractions of several soils before and after removal of a particular clay fraction components: organic matter, iron oxides and aluminum oxides were studied with an application of the water vapor adsorption-desorption method. Changes in micropore radii, volumes and fractal dimensions were observed after the re...

Bentonite, biotite, illite, kaolin, vermiculite and zeolite were acidified or alkalized with hydrochloric acid or sodium hydroxide at concentrations of 0.1, 1.0 and 5.0 mole dm ­3 at room temperature for two weeks. In acid treatments, dissolution of Al prevailed over Si and the opposite was observed in alkali treatments. The XRD patterns showed sev...

This study concentrates on the effects of strong acid or alkaline treatments on subsequent titration curves of soil solid phase. Changes of soil mineral composition and organic matter content were estimated as a background. Samples of upper horizons of three brown, two chernozemic, one pseudopodzolic and three yellow-red soils were treated with hyd...

Bentonite, biotite, illite, kaolin, vermiculite and zeolite were treated with 0.1, 1.0 and 5.0 mol. dm ⁻³ HCl or NaOH. Suspensions of Na homoionic forms of the initial and the treated minerals were back titrated with 0.1 mol. dm ⁻³ NaOH. From back-titration data variable surface charge, Q V , vs. pH dependencies and apparent surface dissociation co...

Surface, charge, and pore properties of three profiles of a solonetzic toposequence: Mollic Solonetz (top), Salic Solonetz (in-between), and Haplic Solonetz (bottom) were studied. A trial of finding relations between the above and other chemical and physical parameters characterizing salt-affected soils was undertaken.Physicochemical soil propertie...

Heavy metal polluted soils from a recent and a former sewage farm were studied in a 2.5 years-column experiment under various irrigation regimes and/ or liming treatment. The copper (Cu), zinc (Zn), lead (Pb), and cadmium (Cd) concentrations in the soil and the leaching of these elements were studied. The amounts of the metals leached differed mark...

Samples of six Polish and three Korean soils were acidified and alkalized with elevated concentrations of hydrochloric acid or sodium hydroxide from 0. 001 to 1 mol dm-3. The pore system of the studied soils was investigated using mercury intrusion ("macropores") and water vapor adsorption ("mesopores") experiments. The characteristics of the pores...

Although cyclodextrins are increasingly used in soil decontamination, little is known about their effects on soil physicochemical properties. In this work, the surface and pore properties of randomly methylated beta-cyclodextrin (RAMEB) and three typical clay minerals were characterized, and the effects of RAMEB concentrations on clay minerals were...

The geometric and energetic characteristics of root surfaces of two wheat (Triticum L.) varieties, Al tolerant (Inia 66/16) and Al sensitive (Henika), were estimated from experimental water vapor adsorption–desorption data. Roots stressed for around 1 week at pH 4 without and with a toxic aluminium level (0.741 mol m–3) were studied at the tillerin...

Effects of 6 years no-tillage (NT), ploughing, disking and the two last treatments combined with loosening on surface area, water vapor adsorption energy, variable charge and fine pore properties of a brown forest soils were studied using water vapor adsorption–desorption, back-titration and mercury intrusion measurements. The studied soil properti...

A two-year pot experiment with alfalfa was carried out on an Albic Luvisol contaminated with As of 120 mg/kg and with Cu/As of 300/120 mg/kg soil. Seven subsequent cuts of the plant were harvested. To study the effect of physicochemical soil melioration on arsenic uptake, the soil was treated with the optimal dose of lime and with various amounts o...

Effects of natural or anthropogenic soil acidification and alkalization on chemical or biological properties have been studied extensively while little is known about changes in physicochemical characteristics, such as surface area or adsorption energy. To investigate this, samples of six Polish soils (Inceptisols, Mollisols) and three Korean soils...

Physicochemical properties of two sandy soils taken from a present and from a former sewage farm were studied during a 2.5 years column experiment, in which lime and irrigation water of various compositions were applied. The amount of exchangeable bases and base saturation percentage in both soils changed markedly during the experiment. These chang...

Changes of microstructural properties of a sandy soil from a former sewage farm due to the leaching of dissolved organic carbon (DOC) were studied. The leaching of DOC at various pH values was induced using sodium hydroxide or hydrochloric acid solutions. The removal of DOC altered the pore properties of the remaining solid. The average pore radius...

Acidic brown forest soil was acidified to various pH's at low moisture content for one week. Changes in the soil surface adsorption and charge properties were studied by water vapor adsorption and black-titration experiments. With the increase of acid load the surface area increased. The apparent surface dissociation constants decreased with acid l...

Acidic brown forest soil was acidified to various pH's at low moisture content during one week. Changes in soil porous system were studied by water vapour desorption and mercury intrusion porosimetry. The soil pore system started to alter at pH around 3.5. At maximal acid load, the pore volume and average pore radii increased up to 30% of their ini...

Soil pH is probably the most important, single, parameter characterizing its fertility. For theoretical and practical reasons the soil pH is usually measured in salt solutions of different strength. The most common solution used in Europe is 1M potassium chloride (KCl) in a soil/solution ratio of 1:2.5 (W/V). The ultimate goal of the international...

Mercury intrusion porosimetry was applied to measure pore properties of selected soils and minerals. Every material was studied as powder, powder wetted with water and hand-formed aggregate. Marked differences in pore volume, average pore radius, pore size distribution and fractal behaviour were observed for the given material at various structural...

Three clay minerals: bentonite, illite and kaolin were treated with acid at different concentration and time. The changes of surface areas, water vapor adsorption energies, variable charge and apparent surface dissociation constants were observed depending on the kind of the mineral and acidification conditions. After acid treatment, the surface ar...

Water vapor adsorption isotherms were used for the estimation of surface areas and adsorption energy distribution functions of roots of barley grown at different pH levels and at a toxic Al level (10 mg·dm−3), induced at tillering and shooting stages of plants growth. Values of surface area as well as energy distributions were the same for the root...

Water vapor adsorption isotherms were measured for samples of kaolin and quartz amended with different amounts of humic acid extracted from a Cambic Arenosol under forest. Applying the approximation of the adsorption isotherms with the BET equation the monolayer capacities (surface areas) for the studied systems were calculated. For kaolin systems...

This paper describes the relationship between crust features and the size and amount of artificial soil matrix, the type of clay minerals and organic matter content. It was proved that raindrop energy has a great influence on the thickness of the crust and that the presence of soil organic matter may inhibit crust formation. Changes in mineral comp...

In this study, changes of adsorption properties of a sandy soil from a former sewage farm due to the leaching of dissolved organic carbon (DOC) were examined. The leaching of DOC at various pH levels was simulated in laboratory experiment using sodium hydroxide as the leaching agent. An increase of pH resulted in an increase of the amount of DOC in...

Measurements of contact angles for glycerol, diiodomethane and cis-decalin drops in solid/ liquid/air systems and for water drops in solid/water/n-octane system were performed. The liquid drops were settled on the surface of pressed pellets made from calcium forms of soil clay fractions: in their natural state and after successive removal of organi...

Changes of cation exchange capacity and of its strong and weak acidic parts were studied for minerals and soils before and after the deposition of humic compounds during the humification process of oak leaves. Humus compounds decreased the exchange capacity of montmorillonite and of montmorillonitic soil, and increased the exchange capacity of kaol...

A B S TRACT: Mineralogical and water adsorption properties of water dispersible clays extracted from five soils of different typology after treatment with acid to different pH levels, were studied. The mineral composition, total and divalent iron content, surface areas and average adsorption energies of water dispersible clays were complicated func...

In this study, we examined the applicability of the theory of gas adsorption on heterogeneous surfaces to assess changes in soil particle surfaces in degrading soils. Soil degradation was simulated by laboratory treatments of gray forest soil (Udic Argiboroll), chernozem soil (Typic Haploboroll), and chestnut soil (Ustolic Orthid) rumples. Water va...

The fraction of mineral surface covered by humic acids and surface free energy components were calculated for samples of quartz and kaolin at different humic acids contents, indicating different mechanisms of surface coating by HA for both minerals.

The mineral composition, total and divalent iron content, surface areas and average adsorption energies of water dispersible clays were complicated functions of pH, reflecting the simultaneous effects of mineral destruction and agregated disruption processes under influences of protons on soils. The magnetic susceptibilities of water dispersible cl...

Fractal parameters of soils become increasingly important in understanding and quantifying transport and adsorption phenomena in soils. It is not known yet how soil degradation affects fractal characteristics of soil pores. We estimated pore surface area fractal parameters from Hg porosimetry data on samples of a Udic Argiboroll, a Typic Haploborol...

Water vapor adsorption isotherms were used for estimation of (apparent) surface areas of samples of limed and unlimed plots of an acidic sandy forest soil. Samples were taken at two microrelief (ridge and furrow) positions from five subsequent 10 cm layers. Values of surface area and CEC correlated linearly with organic matter content but only for...

The dependences between negative charge and pH for organic matter of limed and unlimed profiles of sandy acidic forest soils were determined on the base of ion exchange and titration curves measurements. Subtracting the titration curves of the supernatant from the titration curves of the respective suspensions the quantities of base consumed by sol...

Water vapor adsorption isotherms were measured for soil samples taken from five subsequent 10 cm layers of limed and unlimed Cambic Arenosol under forest. Applying the numerical approximation of adsorption isotherms with an exponential isotherm equation and a local BET model, the surface areas, average adsorption energies and adsorption energies di...

Mineralogy and iron distribution were evaluated for genetic horizons of some soils typical of the region, and were attributed to soil pedogenetic processes. Differences in profile distribution of FeII and magnetic susceptibility, and the processes of mineral transformations, the dominant one of which seems to be the destruction of the mica-group mi...

Based on the concepts of the acidic reactivity of the soil colloids, the physicochemical behaviour of heavy metals in soils is discussed. It is shown that this passes through: ionic (toxic) mobilization in the case of incomplete neutralization of the strongly acidic ion exchanger by strong bases; an optimum, when the strongly acidic ion exchanger i...

The relations governing ion adsorption for overlapped diffuse layers at different surface potentials are shown and discussed. It is shown that particle aggregation may lead to severe changes of the measured adsorption values that can influence the results of agrochemical and physicochemical soil analysis. The variations in the measured amount of io...

An examination of negative surface charge distribution among solid soil phase components and its relations to pH of the equilibrium solution was conducted by model experiments on clays, separated from selected acidic soils. It was noted that negative charge blocking by iron and aluminium oxides occurs, with the most pronounced effect in brown and P...

Investigations of the quantity and behaviour of variable positive charges were carried out using sodium forms of clays separated from selected acidic soils of different origin. The clay fractions investigated possess considerable quantities of positive charge connected with mineral components surfaces. It was noted that organic matter presence lead...

The influence of pH and aluminium on soil clays' negative surface charge was investigated for clays separated from acidic soils of different origin. It was observed that aluminium caused a negative charge decrease due possibly to nonexchangeable Al polycations adsorption in the 4-6 pH range. Aluminium complexing by organic matter can diminish soil...

The behaviour of exchangeable aluminium and hydrogen in the broad range of pH was studied at model conditions on clays taken from acidic soils of different origin. Sodium and aluminium forms of clays were used and ion exchange experiments were performed. On the basis of the results obtained and data previously reported. it was calculated that excha...

Relations among clay particle aggregation, clay composition and the pH of equilibrium solution were studied using sedimentrical scales and sodium forms of clay fractions separated from six acidic soils of different origin. Experimentally obtained sedimentation curves were numerically extrapolated and the mass of sediment taken as a basic factor cha...

The pH influence on the particular forms of soil acidity and the relations between soil neutralization and charge were investigated. Clay fractions of six acidic soils of different origin were examined after conversion into homoionic sodium and aluminium forms. Results indicate that soil exchange acidity should be defined not on the basis of neutra...

Measurements of adsoprtion isotherms of water vapour on clay fractions of five soils prepared by successive removal of organic matter, iron, and aluminium compounds were performed. From isotherms obtained and the Bangham-Razouk's equation, water film pressures were calculated and compared with previously obtained results of surface free energy comp...