Influence of humic acids on soil environment is still subject of scientific discussions. The aim of above studies was to investigate the relationships between selected physicochemical properties of eleven peaty-muck soils and properties of humic acids isolated from these soils. The following parameters were determined for soils: total and organic carbon, density, ash, humifi- cation, and the water absorption index. Humic acids were described by: absorbance at 280 nm, absorbance ratios at 465 and 665 nm, at 260 and 665 nm, elemental composition and atomic ratios: H/C, O/H, O/C, C/N, the degree of internal oxidation, and the content of carboxylic and phenolic groups. Statistical analyses showed that an increase in density, humification, and water absorption indices of soils caused a significant increase in the humic acid parameters: absorbance at 280 nm, the oxygen content, O/H, O/C ratios, inter- nal oxidation degree, and functional groups. Statistically signifi- cant negative correlations were found for the same parameters of soils and for the hydrogen and carbon content as well as the H/C ratio of humic acids. The relationships showed that there was a pos- sibility to express the properties of humic acids on the basis of more simple parameters measured for soil and without time-consuming isolation of humic acids.
Celem niniejszej pracy jest optymalizacja procesu miareczkowania kwasów huminowych w obecności silnie buforujących jonów fosforanowych. Analizą optymalizacyjną objęty został zarówno sposób przygotowania próbek, kalibracja aparatury badawczej, mająca na celu ustalenie odpowiednich parametrów technicznych procesu miareczkowania potencjometrycznego, jak również otrzymanie wiarygodnych i powtarzalnych wyników. W niniejszej pracy badania prowadzone były na modelowych roztworach kwasu huminowego (Aldrich HA). Wszystkie badane roztwory, jak również roztwór titranta, wykonano na bazie 1 M NaCl. Dodatek chlorku sodu stabilizował siłę jonową układu, a tym samym zapobiegał wahaniom mierzonego sygnału. W badaniach optymalizacji procesu miareczkowania uwzględnione zostały aspekty przygotowania próbki: stężenie kwasu huminowego (50 i 500 ppm), stężenie substancji silnie buforującej, jonów fosforanowych (0, 600, 1500, 3500 i 7000 ppm), a także parametry techniczne prowadzenia procesu: objętość titranta (0,1 i 0,01ml) i wartość progowa potencjału dryfu w roztworze (10 i 70 mV·min-1). Z otrzymanych danych wyliczono rozkłady pozornych stałych dysocjacji. Na podstawie uzyskanych charakterystyk zbadane zostały optymalne warunki prowadzenia miareczkowania potencjometrycznego w obecności substancji silnie buforujących.
The object of this study was to determine change of natural buffer capacity of humic acids by strong buffering agents, which were phosphate ions. Studies were carried out on the humic acids extracted from peat soils. Additional information was obtained by determination of water holding capacity, density, ash and pH for peats and optical parameterQ4/6 for humic acids. Humic acid suspensions exhibited the highest buffer properties at low pH and reached maximum at pH ~ 4. Phosphates possessed buffer properties in the pH range from 4.5 to 8.0. The maximum of buffering was at pH~6.8 and increased proportionally with an increase in the concentration of phosphate ions. The study indicated that the presence of phosphate ions may strongly change natural buffer capacity of humic acids by shifting buffering maximum toward higher pH values. Significant correlations were found for the degree of the secondary transformation with both the buffer capacity and the titrant volume used during titration.
A study was made on the effect of the presence of rubble of building materials on the buffer capacity of loess soil (Typic Entrochrept acc. to FAO). Ground building materials: brick, concrete, foam concrete and mortar were added to the soil. Additionally, identical mixtures were prepared, with an addition of 6% of peat as reclamation material for the model mixtures. The prepared mixtures were subjected to thermal stress. They were frozen to –20°C, then the samples were transferred to a temperature of 30°C, all the time maintaining constant moisture at the level of 25% by weight, that is in the moisture range between the field water capacity and the wilting point for the loess soil. In the course of the study a significant impact of the building materials on the loess soil buffer capacity was observed. They varied with relation to the type of building material added, the time of thermal stress, and the additional presence of peat. It was found that the presence of building materials increased the buffering capacity of the soil in relation to substances of acidic nature. The presence of peat caused a reversal of this process. The ability of peat to remediate a soil degraded with building materials was also confirmed in the course of the study of the effect of thermal stress on the buffer capacity of the soil and its mixtures. With extension of the time of thermal stress, there was a decrease in the differences in buffer capacity between the particular mixtures and the soil.
The main aim of the paper was to study the effect of coagulation of copper ions on dissolved form of humic acids. Research material was isolated from four peaty muck soils (Terric Histosols). The soils were described by means of the Springer humification number, secondary transformation index, ash content and pH in H2O and in KCl. For the studied humic acids, surface charge was determined, E4/E6 which described the degree of concentration of the chain of aromatic carbons of the humic acids and could be used as their humification number, and the elemental composition and atomic ratios were determined as well. Systems composed of humic acids and increasing concentrations of copper ions were investigated at pH 5 and in the copper concentration range of 0-40 mg dm-3, at constant concentration of humic acids. Coagulation of solutions was studied by measurement of changes of organic carbon and copper ions concentration in liquid phase at pH 5 as well as by observation of absorbance changes at wavelength 465 nm in series of prepared solutions. The results showed that coagulation of experimental systems consisted mainly in humic acid coagulation. In a certain range of concentration of copper added to solutions, metal also partly precipitated and went to the solid phase together with humic carbon, which indicated coagulation of complexed compound of humic acids with copper. At high copper concentration, ionic strength had a dominant influence on coagulation of humic acids. Copper ions stayed all in liquid phase, whereas almost total organic carbon passed to precipitate, which resulted from interactions with electrolyte ions.
The objective of the study was optical characterisation of humic acids extracted from organic wastes. The study included wastes such as turkey manure, solid sludge from sewage treatment plant Hajdów, substrate after mushrooms growth and materials obtained after the fermentation of residues from a biogasing plant, as well as charcoal derived from biomass biogasing pyrolysis. The tested organic wastes were analysed for the content of organic carbon and for their humification degree. The humification number of investigated wastes was obtained according to the Springer method. Humic acids were extracted from the wastes according to the Schnitzer method. The acids extracted were characterised in terms of their optical properties. A correlation was found between yield of humic acids and organic matter content in organic wastes and their degree of humification. The parameters q4/6 for examined organic compounds were characterised to fulvic acids, and the values of ΔlogK indicated a low or medium humification degree.
W pracy wyznaczono całkowitą objętość porów oraz wymiar fraktalny mieszanin gleby lessopodobnej i preparatu keratyno-koro-mocznikowego (KKM). Pomiary porowatości prowadzono na porozymetrze rtęciowym. Z danych porozymetrycznych obliczano powierzchniowy wymiar fraktalny metodą Neimarka. Zróżnicowanie w ilości rtęci wtłoczonej do badanych próbek mieszanin gleba+preparat KKM było wyraźnie widoczne i zawierało się w przedziale od 92,5 do 146,8 mm3 ·g-1. Nie stwierdzono proporcjonalnej zależności pomiędzy zawartością preparatu KKM w mieszaninie, a objętością rtęci wtłoczonej do próbek. Na krzywych rozkładu porów w funkcji ich promienia dla większości mieszanin gleba+KKM oraz dla kompostu KKM występował jeden pik, co świadczy o jednorodnej strukturze (występowaniu porów o podobnych rozmiarach). Wymiar fraktalny (DHg) mieszanin gleby lessopodobnej z KKM był w przedziale od 2,539 do 2,669. Wymiar fraktalny mieszanin wzrastał wraz z wielkością dawki KKM w glebie. Wymiary fraktalne wskazywały na niejednorodność geometryczną badanych mieszanin.
The main goal of this study was to investigate the effect of biochar on hygroscopic water content (maximum hygroscopicity) of grey-brown podzolic soil (Haplic Luvisol). The biochar was applied to the soil of sub-plots under fallow and grassland in the amount of 0 (control), 10, 20 and 30 Mg·haˉ¹. Soil samples were taken three times per year during the period of 2013-2015. Sorption isotherms of water vapour were determined for all studied samples and the maximum hygroscopicity (MH) was calculated from the relative water vapour pressure at p·p0ˉ¹ = 0.965. Value of the MH varied from 1.5 to 3%. The effect of biochar addition to soil on hygroscopic water content was ambiguous. Addition of biochar caused a slight decrease in MH value in the case of the grassland. For the fallow, a positive effect of biochar addition was observed.
Celem badań była analiza chemiczna odpadów organicznych w celu wykorzystania ich jako wsady do fermentacji metanowej. Badaniami objęto odpady takie jak pomiot indyczy, osad stały Hajdów, podłoże po pieczarkach oraz pozostałość pofermentacyjna stała po odciśnięciu części płynnej i wysuszona pozostałość pofermentacyjna stała i węgiel drzewny pochodzący ze zbiogazowania biomasy w wyniku pirolizy. Badane materiały analizowano na zawartość węgla organicznego oraz miedzi, ołowiu, kadmu, manganu i wapnia. Stwierdzono, że ilości węgla organicznego i analizowanych metali w badanych odpadach oraz osadach pofermentacyjnych było różne. Najwyższą zawartością węgla organicznego charakteryzował się pomiot indyczy. Najwyższą zawartość ołowiu stwierdzono w pomiocie indyczym i w osadzie z Hajdowa, a obecność żelaza w osadzie stałym z Hajdowa.
The main aim of the study was the determination of the content of selected metal ions in soils originating from Polesie Lubelskie and Biebrza River Region, as well as an attempt at relating the results obtained to the degree of secondary transformation of studied soils. All the soils belonged to peat-muck soils and differed from each other in their secondary transformation index. The study included analyses of the content of potassium, calcium, magnesium and manganese with the use of absorption atomic spectroscopy for the determination of the concentration of those metals. At the next stage of the study, relationships between the secondary transformation index of peat-muck soils and selected metal contents were examined. Weak linear relationships were found for the secondary transformation index and the content of calcium, manganese and potassium. A more complex situation was observed for the relation of magnesium ions. The lack of a straight-line trend could be explained in this case by the effect of chemical processes occurring in particular classes of mucks transformation on magnesium ion binding.
Adsorption of nitrogen on the rapeseed oil cake and rapeseed oil cake with wheat meal extrudates was investigated. The results are presented as adsorption-desorption isotherms. The Brunauer-Emmet and Teller equation was used to analyse the experimental sorption data. To obtain estimates of the surface area and surface fractal dimension, the sorption isotherms were analyzed using the Brunauer-Emmet and Teller and Frenkel-Halsey-Hill equations. Mesopore analysis was carried out using the Dollimore and Heal method. The properties and surface characteristic of rapeseed oil cake extrudates are related to different basic properties of particular samples and duration of the extrusion process. Extrusion conditions lead to essential differences in particular products. For all kinds of rapeseed oil cakes the amount of adsorbed nitrogen was different, but for the rapeseed oil cake extrudates a large amount of adsorbed nitrogenwas observed. The average surface area of the rapeseed oil cake extrudates was about 6.5-7.0 m2 g-1, whereas it was equal to about 4.0-6.0 m2 g-1 for rapeseed oil cake with the wheat meal extrudates. In the case of non-extruded rapeseed oil cake and wheat meal, the dominant group included ca. 2 and 5 nmpores. The values of surface fractal dimension suggested that the surface of the extrudates was more homogenous than that of the raw material. Duration of the extrusion process to 80 s resulted in a decrease in the specific surface area, surface fractal dimension, and porosity of the extrudates.
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