The sorption of naphthalene and naphthol from water solutions by peat, chernozem, and humic and fulvic acids was studied. The sorption isotherms of naphthalene and naphthol by chernozem corresponded to the Langmuir isotherms. More complex nonlinear isotherms were obtained for peat. Binding of naphthalene and naphthol by humic and fulvic acids can proceed through hydrophobic interactions with aromatic fragments of humic substances and hydrogen bonds between the polar groups of humic molecules and naphthol OH groups. 相似文献
The influence of humic acids of different origins on the growth of bacterial cultures of different taxa isolated from the
soil and the digestive tracts of earthworms (Aporrectodea caliginosa)—habitats with contrasting conditions—was studied. More than half of the soil and intestinal isolates from the 170 tested
strains grew on the humic acid of brown coal as the only carbon source. The specific growth rate of the bacteria isolated
from the intestines of the earthworms was higher than that of the soil bacteria. The use of humic acids by intestinal bacteria
confirms the possibility of symbiotic digestion by earthworms with the participation of bacterial symbionts. Humic acids at
a concentration of 0.1 g/l stimulated the growth of the soil and intestinal bacteria strains (66 strains out of 161) on Czapek’s
medium with glucose (1 g/l), probably, acting as a regulator of the cell metabolism. On the medium with the humic acid, the
intestinal bacteria grew faster than the soil isolates did. The most active growth of the intestinal isolates was observed
by Paenibacillus sp., Pseudomonas putida, Delftia acidovorans, Microbacterium terregens, and Aeromonas sp.; among the soil ones were the representatives of the Pseudomonas genus. A response of the bacteria to the influence of humic acids was shown at the strain level using the example of Pseudomonas representatives. The Flexom humin preparation stimulated the growth of the hydrocarbon-oxidizing Acinetobacter sp. bacteria. This effect can be used for creating a new compound with the elevated activity of bacteria that are destroyers
of oil and oil products. 相似文献
Data on the distribution of the components of oil products that have accumulated in the arctic tundra soils of the Bol’shoi Lyakhovskii Island (the Novosibirskie Islands) under the impact of technogenic loads are analyzed. The examined soils differ in the vertical and lateral distribution patterns of the methanenaphthenic and naphthenic hydrocarbons and in the degree of their transformation. This is determined by the position of particular soils in the catenas and by the sorption of particular hydrocarbon compounds in the soils. The portion of light molecular-weight hydrocarbons in the upper horizons decreases by two-ten times in comparison with the deeper soil layers. In the lateral direction, the twofold difference in the contents of the methane-naphthenic and naphthenic hydrocarbons in the upper horizons is seen. The degree of transformation of the hydrocarbons under the impact of microbiological processes depends on the aeration conditions, the depth of permafrost table, the composition of oil products, and the soil organic matter content. 相似文献
Eurasian Soil Science - The content of polycyclic aromatic hydrocarbons (PAHs) and carbon isotope composition in the peat of a palsa near Eletsky settlement, Vorkuta urban district, Komi Republic... 相似文献
Eurasian Soil Science - The influence of land use history and chemical properties of soils on their allelotoxicity has been studied. Twelve soil samples collected on the Russian Plain and seeds of... 相似文献
The effect of excreta of earthworm species Aporrectodea caliginosa and Eisenia fetida on the mineralization of nitrogen compounds in soils has been studied. A single application of excreta obtained from three earthworms in one day increased the formation of nitrate nitrogen compounds in the soil by 10–50%. The application of ammonium nitrogen (in the form of NH4Cl) in amounts equivalent to the ammonium nitrogen content in the daily excreta of three earthworms had the same effect on the mineralization of nitrogen compounds. The effect of earthworm excreta, as well as the effect of ammonium nitrogen, on the nitrification process was an order of magnitude higher than their contribution to the formation of nitrates due to the oxidation of the introduced ammonium. Hence, ammonium—an important component of the earthworm excreta—can exert a stimulating effect on nitrification processes in the soil and produce long-term cumulative effects that are much more significant than the direct effect of this nitrogen compound. 相似文献
The results of a model laboratory experiment in which the acidic oil-polluted sand was incubated for three months in the presence of palygorskite or bentonite clays supplemented with mineral fertilizers and lime under conditions of periodic wetting and drying are presented. A reliable decrease in the total content of nonpolar and weakly polar CCl4 extractable organic compounds and of the weakly polar compounds was established. The content of the nonpolar fraction, the amount of C14–C36 alkanes in its composition, and the (C17 + C18)/(Ci–15 + Ci–16) ratio, which was indicative of microbiological destruction of hydrocarbons, decreased significantly in the experiment with the palygorskite clay. 相似文献
The study was conducted to quantify the polycyclic aromatic hydrocarbons (PAHs) accumulation in urban soils from different functional areas via atmospheric inputs with particulate matter.
Materials and methods
PAH concentration and pattern were measured in the particulate matter of snow depositions, in the upper layers of artificial soils from densely built-up areas and in the undisturbed natural soils (Umbric Retisols) from green park area. Samples were collected in 2011–2013 at 58 sites with different traffic activities located at the territory of the Eastern Administrative Okrug of Moscow. The soil samples and filters with particulate matter were extracted by pressurized liquid extraction using Dionex ASE200. Clean-up analyses were performed on SPE cartridges filled with silica gel. Concentrations of PAHs were determined by high-performance liquid chromatography using an Agilent 1100 System equipped with fluorescent detector.
Results and discussion
Mean values of PAH input with snow particles were 45–57 μg/m2 for recreational and residential zones, and 140–264 μg/m2 for traffic zones. The samples of depositions from different functional areas showed a similar PAH pattern and consisted primarily of 3–4-ring PAHs. Total PAH concentrations in upper layers of artificial soils showed similar mean values of 1.43–2.21 μg/g for all functional zones. The PAH content in soils from the park area was twofold lower than that from the built-up area (0.34–0.63 μg/g), despite equal levels of atmosphere contamination on these territories. The upper layers of natural soils from recreational and traffic zones showed slight differences in PAH content, though PAH input with snow was fivefold higher in the traffic zone. Compared with airborne depositions, soils contained significant amounts of 5–6-ring PAHs.
Conclusions
A high level of soil PAH contamination in urban areas of Moscow, several orders of magnitude higher than the current PAH input to them from the atmosphere, indicates a lack of direct connection of the PAH pool in soils with this source. The high PAH content in the upper layer of constructed soils can be the result of repeated use of materials subjected to a constant technogenic impact for the production of artificial soils.
A sorbent of oil and water-dissolved oil components is prepared from organobentonite, and its ability to absorb those products is assessed. Bentonite modified with dodecyltrimethylammonium added at a rate of 0.5 CEC was found to absorb 1.6 times as many oil components as nonmodified bentonite. The obtained sorbent has good flotage characteristics due to the formation of a durable film on the surface of oil spots, which can be easily removed. The sorbent is effective in extracting water-soluble oil compounds and has no toxic effect on Paramecium caudatum and Ceriodaphnia affinis. When the temperature is lowered from 22 to 10°C, sorbent efficiency is reduced. 相似文献
