Anna Karczewska

Mercury accumulation in the surface layers of mountain soils: A case study from the Karkonosze Mountains, Poland

The study was aimed to examine total concentrations and pools of Hg in surface layers of soils in the Karkonosze Mountains, dependent on soil properties and site locality. Soil samples were collected from a litter layer and the layers 0-10 cm and 10-20 cm, at 68 sites belonging to the net of a monitoring system, in two separate areas, and in three altitudinal zones: below 900 m, 900-1100 m, and over 1100 m. Air-borne pollution was the major source of mercury in soils. Hg has accumulated mainly in the litter (where its concentrations were the highest), and in the layer 0-10 cm. Hg concentrations in all samples were in the range 0.04-0.97 mg kg(-1), with mean values 0.38, 0.28, and 0.14 mg kg(-1) for litter and the layers 0-10 cm and 10-20 cm, respectively. The highest Hg concentrations in the litter layer were found in the intermediate altitudinal zone, whereas Hg concentrations in the layer 0-10 cm increased with increasing altitude. Soil quality standard for protected areas (0.50 mg kg(-1)) was exceeded in a few sites. The pools of Hg accumulated in soils were in the range: 0.8-84.8 mg m(-2), with a mean value of 16.5 mg m(-2), and they correlated strongly with the pools of stored organic matter.

Strong solutions to stochastic Volterra equations

In this paper stochastic Volterra equations admitting exponentially bounded resolvents are studied. After obtaining convergence of resolvents, some properties for stochastic convolutions are studied. Our main results provide sufficient conditions for strong solutions to stochastic Volterra equations.

Copper, Zinc, and Lead Fractions in Soils Long-Term Irrigated with Municipal Wastewater

Long-term irrigation with municipal wastewater may lead, even in spite of intense farming, to an accumulation of organic matter, nutrient elements, and trace metals in soils. Excessive increases of heavy metals may pose a potential risk to the food chain and provoke restrictions for the further cultivation of sensitive crops. Copper (Cu), zinc (Zn), and lead (Pb) forms in soils under long-term irrigation (for 100–120 years) with treated wastewater of Wroclaw were investigated by using selective seven-step sequential extraction (procedure of Zeien-Bruemmer) for partitioning the metals into operationally defined fractions, likely to be released in solution under various environmental conditions. The largest fraction of Cu, Pb, and particularly Zn in nonirrigated (control) soils was strongly bound in a residual form, while the percentage of exchangeable and the most labile fractions were negligible. Total concentration of metals in irrigated soils was elevated, and significant redistribution of metals among phases was observed. Percentages of residual fraction of Cu and Pb were no more than 25% (Zn < 40%), while significantly increased contribution of fractions occluded on iron (Fe) oxides and organically bound Cu. Exchangeable and readily mobile forms of Zn are predominant zinc fractions in soils irrigated with wastewater.

Energy invariant for shallow-water waves and the Korteweg-de Vries equation: Doubts about the invariance of energy.

It is well known that the Korteweg-de Vries (KdV) equation has an infinite set of conserved quantities. The first three are often considered to represent mass, momentum, and energy. Here we try to answer the question of how this comes about and also how these KdV quantities relate to those of the Euler shallow-water equations. Here Lukes Lagrangian is helpful. We also consider higher-order extensions of KdV. Though in general not integrable, in some sense they are almost so within the accuracy of the expansion.

A new nonlinear equation in the shallow water wave problem

In this paper, a new nonlinear equation describing shallow water waves with the topography of the bottom directly taken into account is derived. This equation is valid for weakly nonlinear, dispersive, and long wavelength limits. Some examples of soliton motion for various bottom shapes obtained in numerical simulations according to the derived equation are presented.In the paper a new nonlinear equation describing shallow water waves with the topography of the bottom directly taken into account is derived. This equation is valid in the weakly nonlinear, dispersive and long wavelength limit. Some examples of soliton motion for various bottom shapes obtained in numerical simulations according to the derived equation are presented.

Arsenic extractability and uptake by velvetgrass Holcus lanatus and ryegrass Lolium perenne in variously treated soils polluted by tailing spills.

Phytostabilization should be considered as an appropriate phytoremediation technique to restore the area affected by tailing spills in Zloty Stok, where arsenic ores were mined and processed for several centuries. The study aimed to compare the suitability of velvetgrass (Holcus lanatus L.) and ryegrass (Lolium perenne L.) for development of plant cover in that area. Various treatments commonly applied to support phytostabilization were examined. A pot experiment was carried out to assess the effects of soil amendment with phosphate (P), sewage sludge (SS) and iron salts (Fe) on arsenic extractability and its uptake by grass. Four kinds of soil material, containing 356-5350 mg kg(-1) As, were examined. Velvetgrass proved to be more resistant than ryegrass to the toxicity of soil arsenic. Ammonium sulphate extractability of As in soils correlated well with As concentrations in the biomass of both grass species. In three of four tested soils, application of Fe failed to decrease As extractability and to reduce its concentrations in the aboveground parts of grasses. Application of P and SS resulted in increased As solubility in soils, but their effects on plant biomass and As uptake were ambiguous. SS had a strong beneficial influence on the growth of velvetgrass, while such an effect was not observed for ryegrass.

INFLUENCE OF SOIL PROPERTIES AND PHOSPHATE ADDITION ON ARSENIC UPTAKE FROM POLLUTED SOILS BY VELVETGRASS (HOLCUS LANATUS)

Four kinds of soil material were used in a pot experiment with velvetgrass (Holcus lanatus). Two unpolluted soils: sand (S) and loam (L) were spiked with sodium arsenite (As III) and arsenate (As V), to obtain total arsenic (As) concentrations of 500 mg As kg−1. Two other soils (ZS I, ZS III), containing 3320 and 5350 mg As kg−1, were collected from Zloty Stok where gold and arsenic ores were mined and processed for several centuries. The effects of phosphate addition on plants growth and As uptake were investigated. Phosphate was applied to soils in the form of NH4H2PO4 at the rate 0.2 g P/kg. Average concentrations of arsenic in the shoots of velvetgrass grown in spiked soils S and L without P amendment were in the range 18–210 mg As kg−1 d.wt., whereas those in plants grown on ZS I and ZS II soils were considerably lower, and varied in the range 11–52 mg As kg−1 d.wt. The addition of phosphate caused a significant increase in plant biomass and therefore the total amounts of As taken up by plants, however, the differences in As concentrations in the shoots of velvetgrass amended and non-amended with phosphate were not statistically significant.

Numerical solutions to integral equations equivalent to differential equations with fractional time

Numerical solutions to integral equations equivalent to differential equations with fractional time This paper presents an approximate method of solving the fractional (in the time variable) equation which describes the processes lying between heat and wave behavior. The approximation consists in the application of a finite subspace of an infinite basis in the time variable (Galerkin method) and discretization in space variables. In the final step, a large-scale system of linear equations with a non-symmetric matrix is solved with the use of the iterative GMRES method.

Stochastic Volterra equations driven by cylindrical Wiener process

Abstract.In this paper, stochastic Volterra equations driven by cylindrical Wiener process in Hilbert space are investigated. Sufficient conditions for existence of strong solutions are given. The key role is played by convergence of α-times resolvent families.

Solutions to stochastic fractional oscillation equations

Abstract We formulate a fractional stochastic oscillation equation as a generalization of Bagley’s fractional differential equation. We do this in analogy with the case for Basset’s equation, which gives rise to fractional stochastic relaxation equations. We analyze solutions under some conditions of spatial regularity of the operators considered.