Mirosław Kobierski

On the origin of surfaces-dependent growth of benzoic acid crystal inferred through the droplet evaporation method

Crystal growth behavior of benzoic acid crystals on different surfaces was examined. The performed experiments documented the existence of very strong influence introduced by polar surfaces as glass, gelatin, and polyvinyl alcohol (PVA) on the growth of benzoic acid crystals. These surfaces impose strong orientation effect resulting in a dramatic reduction of number of faces seen with x-ray powder diffractions (XPRD). However, scrapping the crystal off the surface leads to a morphology that is similar to the one observed for bulk crystallization. The surfaces of low wettability (paraffin) seem to be useful for preparation of amorphous powders, even for well-crystallizable compounds. The performed quantum chemistry computations characterized energetic contributions to stabilization of morphology related faces. It has been demonstrated, that the dominant face (002) of benzoic acid crystal, growing on polar surfaces, is characterized by the highest densities of intermolecular interaction energies determining the highest cohesive properties among all studied faces. Additionally, the inter-layer interactions, which stand for adhesive properties, are also the strongest in the case of this face. Thus, quantum chemistry computations providing detailed description of energetic contributions can be successfully used for clarification of adhesive and cohesive nature of benzoic acids crystal faces.

On the origin of surface imposed anisotropic growth of salicylic and acetylsalicylic acids crystals during droplet evaporation

In this paper droplet evaporative crystallization of salicylic acid (SA) and acetylsalicylic acid (ASA) crystals on different surfaces, such as glass, polyvinyl alcohol (PVA), and paraffin was studied. The obtained crystals were analyzed using powder X-ray diffraction (PXRD) technique. In order to better understand the effect of the surface on evaporative crystallization, crystals deposited on glass were scraped off. Moreover, evaporative crystallization of a large volume of solution was performed. As we found, paraffin which is non-polar surface promotes formation of crystals morphologically similar to those obtained via bulk evaporative crystallization. On the other hand, when crystallization is carried out on the polar surfaces (glass and PVA), there is a significant orientation effect. This phenomenon is manifested by the reduction of the number of peaks in PXRD spectrum recorded for deposited on the surface crystals. Noteworthy, reduction of PXRD signals is not observed for powder samples obtained after scraping crystals off the glass. In order to explain the mechanism of carboxylic crystals growth on the polar surfaces, quantum-chemical computations were performed. It has been found that crystal faces of the strongest orientation effect can be characterized by the highest surface densities of intermolecular interactions energy (IIE). In case of SA and ASA crystals formed on the polar surfaces the most dominant faces are characterized by the highest adhesive and cohesive properties. This suggests that the selection rules of the orientation effect comes directly from surface IIE densities.

Zawartość miedzi i cynku w glebie lekkiej nawożonej popiołem ze słomy jęczmienia, pszenicy i rzepaku

Abstract The use of cereals and rapeseed straw ash in the fertilisation of soils has been one of the alternative straw management methods. Adding high ash rates to soil decreased its acidity and increased the total content of copper and zinc as well as the forms of those metals extracted with the DTPA solution. Due to a low natural richness of those soils in bioavailable metal forms, the ash application to fertilise light soil, despite a low content of copper and zinc in the post-burning ash waste, must be still considered beneficial. The use of barley, wheat and rapeseed straw ash at the rate exceeding 2 Mg×ha.1 resulted in a significant increase in the total content of copper and zinc and their forms available to plants. Streszczenie Wykorzystanie popiołów ze spalenia słomy zbóż i rzepaku w nawożeniu gleb pozostaje jednym z alternatywnych sposobów ich zagospodarowania. Dodatek wy sokich dawek popiołu do gleby spowodował wzrost wartości pH oraz wzrost całkowi- tej zawartości miedzi i cynku, a także form tych metali ekstrahowanych roztworem DTPA. Pomimo niskiej zawartości miedzi i cynku w odpadach paleniskowych ich zastosowanie wr nawożeniu gleb lekkich należy uznać za korzystne ze względu na niską naturalną zasobność tych gleb wr formy biodostępne metali. Zastosowanie popiołu ze słomy jęczmienia, pszenicy i rzepaku wr dawce przekra- czającej 2 Mg-ha 1 spowodowało istotny wzrost całkow itej zaw artości miedzi i cynku wr glebie oraz ich fonn dostępnych dla roślin

Clay minerals from Weichselian glaciolimnic sediments of the Sępopolska Plain (NE Poland)

Clay minerals from Weichselian glaciolimnic sediments of the Sępopolska Plain (NE Poland) Glaciolimnic deposits sampled from three sedimentation reservoirs located on the Sępopolska Plain (northeastern Poland) were investigated. The material under study was deposited in the recession phase of the Pomeranian phase of Vistula (Weichselian) glaciation. The clay fraction was separated by centrifugation after preparation according to Jackson. Mineralogical investigations were done by X-ray diffraction. The analysed deposits had a similar complex composition of clay minerals. The main components were illites mixed with the illite/smectite mineral with percentages < 10 % S. Another part were minerals of the illite/smectite type which had differentiated content of smectite layers (mainly 80-90 % S). There were also chlorite minerals, probably as mixed layer minerals of the chlorite/vermiculite type or HIV with a negligible amount of chlorite layers. The results indicated that all the deposits were of the same age as well as similar deposited material and the samples are different from typical Pomeranian till and typical limnic material of the same age. Small differences observed among the deposits of specific sedimentation reservoirs were probably the result of later processes.

Soil Quality Assessment of Phaeozems and Luvisols from the Kujawy Region (Central Poland) / Ocena cech użytkowych czarnych ziem i gleb płowych rejonu Kujaw

Abstract To assess the soil quality of Phaeozems and Luvisols from Kujawy region (Kujawy-Pomerania Province, Poland), the soil quality indicators such as: content of organic matter and nutrients, as well as bulk density were used. The soils showed similar inherent properties (soil texture, depth to parent material, type of clay) and management practices (tillage, crop rotation, nutrient application). The following properties were determined: bulk density, grain size composition, exchangeable acidity, concentration of available forms of potassium, phosphorus and magnesium, and the content of total organic carbon (TOC) and nitrogen (Nt). The amounts of dissolved organic carbon (DOC) and dissolved nitrogen (DN) were measured in the solution obtained after extraction with 0.004 M CaCl2. The stock of TOCs, Nts and DOCs, and DNs were calculated. The total organic carbon content in surface horizon of Phaeozems was significant higher (13.9-20.1 g·kg-1) than in Ap horizon of Luvisols (8.3-11.0 g·kg-1), which is a consequence of their origin. The stock of organic carbon in Ap horizon fell within 5.89 to 8.49 kg·m2 in Phaeozems and 3.80 to 4.81 kg·m2 in Luvisols. Although Phaeozems demonstrated a significant higher content of TOC, as compared with Luvisols, the amount of dissolved organic carbon was similar in both soil types, which points to a higher share of DOC in the total organic carbon content in Luvisols (up to 17.5% in Et horizon). The amounts of dissolved organic carbon and dissolved nitrogen and their stock do not depend on the type of soils if the management practices are similar.

EVALUATION OF THE CONTENT OF HEAVY METALS IN FLUVISOLS OF FLOODPLAIN AREA DEPENDING ON THE TYPE OF LAND USE

The aim of the research was the evaluation of the potential contamination with heavy metals in Fluvisols, used as grasslands and arable soils of Vistula River floodplain in the area of the Chelminski and Nadwiślanski Complex of Landscape Parks. The indicators proposed by Hakanson allow to evaluate the potential ecological risk of the contamination with heavy metals associated with the accumulation of one metal or a combination of multiple metals. The mean total content of Cd, Pb, Ni Cu, Zn, Mn, as well as Fe in Fluvisols at the depth of 120–150 cm was assumed as the content of the local geochemical background and it was: 1.0 mg·kg-1, 22.8 mg·kg-1, 26.9 mg·kg-1, 1.4 mg·kg-1, 60.8 mg·kg-1, 591 mg·kg-1, and 17.6 g·kg-1, respectively. The values of the indicators such as contamination factor (CF), enrichment factor (EF) revealed higher levels of the accumulation of heavy metals in the soils of grasslands, which shows that the method of their use has a significant effect on the total metal content. Contamination with heavy metals in the surface layer of the investigated Fluvisols was found, and in terms of the content with cadmium a moderate and considerable potential ecological risk was reported. Due to the fact that no unfavourable effect of trace elements on the riverside environment was proved and that the floodplain areas are under agricultural use, to evaluate the contamination with metals, the limit values for the soils of agricultural land were assumed as stipulated in the Regulation of Minister of the Environment of September 9, 2002. According to that criterion, the soils studied do not qualify as contaminated with metals. Only in one of the soil sampling points the total content of zinc was higher than the one determined as the maximum for agricultural land soils, namely 350 mg·kg-1. A significantly positive correlation was noted between the content of C org and the total content of metals as well as very numerous interactions between metals. The results of cluster analysis confirm that the method of use determines the concentration of metals in the surface layer of the Fluvisols studied.