Carbon dioxide affects charge accumulation in leaves

This work was supported by grants OKKFT (Tt) 222/1988 and 310/1988 from the National Foundation of Technical Development (Hungary). Govindjee was supported by an interdisciplinary McKnight Research Grant to the University of Illinois at Urbana, IL (USA).     

Acetochlor as a soil pollutant

Acetochlor is a widely used herbicide all over the world. Similarly to other organic pollutants, the environmental fate of the acetochlor is strongly related to its adsorption properties. Static adsorption equilibrium measurements were carried out at 25 degrees C on different types of Hungarian soils characterized by varying amounts of organic matter and pH values. Isotherms obtained under different conditions, as well as on various soils, exhibit a similar shape, thus indicating a two-step adsorption process. The plots cannot be interpreted according to the classes of isotherms suggested by Giles. The adsorption coefficients (K) were estimated from the initial slope of the curves. These values were determined not only by the type of the soil, but also by the composition of the aqueous media. The organic matter adsorption coefficients (Kom) were also calculated and they were approximately identical for soils of high organic matter. Due to the low value of the adsorption coefficients, the acetochlor is a rather mobile pollutant of the soil posing a potential danger to the aquatic environment. For soils with high organic content, the Kom values are similar to each other and, due to the significant coverage of the inorganic surfaces, the adsorption is controlled by the solute-organic substance interactions. The adsorption of weakly polar compounds, however, is remarkable even on those soils where the organic content is low. In this case, the binding is governed by the solute-inorganic surface interactions. This conclusion is nicely proved by the adsorption of the acetochlor on quartz. According to our hypothesis, the second part of the adsorption step is controlled by the solute-adsorbed solute interactions. The role of the organic matter in this region of the isotherm is probably negligible. As the organic matter content of the soils plays an important role in the acetochlor adsorption, humic substances must have a strong influence upon the transport of this compound. Experiments to obtain adsorption isotherms of further pesticides and the development of a quantitative model are in progress.     

Environmental information system for visualizing environmental impact assessment information

The Institute of Environmental Engineering at the University of Pannonia has undertaken the challenge to develop an online environmental information system. This system is able to receive and process the collected environmental data via Internet. The authors have attached importance to the presentation of the data and have included other comprehensible information for laymen as well in order to work out visualisation techniques that are expressive and attract attention for environmental questions through the developed information system. The ways of visualizing physical and chemical parameters of surface water and the effects of motorway construction were examined.     

Sensitivity analysis of an ozone deposition model

In this study, sophisticated sensitivity analyses of a detailed ozone dry deposition model were performed for five soil types (sand, sandy loam, loam, clay loam, clay) and four land use categories (agricultural land, grass, coniferous and deciduous forests). Deposition velocity and ozone flux depend on the weather situation, physiological state of the plants and numerous surface-, vegetation-, and soil-dependent parameters. The input data and the parameters of deposition-related calculations all have higher or lower spatial and temporal variability. We have investigated the effect of the variability of the meteorological data (cloudiness, relative humidity and air temperature), plant-dependent (leaf area index and maximum stomatal conductance) and soil-dependent (soil moisture) parameters on ozone deposition velocity. To evaluate this effect, two global methods, the Morris method and the Monte Carlo analysis with Latin hypercube sampling were applied. Additionally, local sensitivity analyses were performed to estimate the contribution of non-stomatal resistances to deposition velocity. Using the Monte Carlo simulations, the ensemble effect of several nonlinear processes can be recognised and described. Based on the results of the Morris method, the individual effects on deposition velocity are found to be significant in the case of soil moisture and maximum stomatal conductance. Temperature and leaf area index are also important factors; the former is primarily in the case of agricultural land, while the latter is for grass and coniferous forest. The results of local sensitivity analyses reveal the importance of non-stomatal resistances.     

Waste as alternative fuel – Minimising emissions and effluents by advanced design

This paper reviews the utilisation of waste as an alternative fuel, commonly referred to as Waste-to-Energy (WTE). The paper contains a comprehensive survey of the literature published in this field with comparative analysis of different approaches and methods. The main features and properties of municipal and industrial waste have been analysed as these can vary significantly from location to location and year to year. The paper discusses the applicability and limitations of current and developing WTE technologies as well as new and emerging WTE technologies and the recent developments in design of for producing heat, power and fuels. Methodologies that are considered include criteria for technology selection, together with procedures that comply with the environmental EC regulations Best Available and Best Applicable Techniques (BREFs).     

Interspecific distribution and co-associations of chemical elements in the liver tissue of marine mammals from the Polish Economical Exclusive Zone, Baltic Sea

Concentrations of Al, B, Ba, Cd, Co, Cr, Cu, Fe, Ga, Hg, Li, Mn, Mo, Ni, Pb, Se, Si, Sr, Tl, V, Zn, Ca, K, Mg, Na and P in the livers of marine mammals obtained from by-catches or stranded on beaches on the Polish Baltic coast were determined by ICP-MS or ICP-AES and CV AAS. Interspecific diversity with respect to the contents of these elements was found in cetaceans and pinnipeds. The diverse Cd contents in the livers of these mammals can be attributed to the variable concentrations of this element in their food. Mercury was correlated with age and can reach high concentration associated with higher level of Se in older specimens. No significant relationships were found between concentration of the chemical elements studied and nutritional status/condition of the Baltic harbour porpoises as well as between their concentration in specimens from the Gulf of Gdańsk and open Baltic. It seems that the nutritional and health status of the specimens studied is generally enough good since the specimens studied were not stranded on beach because of starvation but almost incidentally caught in salmon gill nets. Strong correlations were found between the macroelements analysed, i.e. for the Ba-Ca-Sr, Ca-K, Ca-Mg, Mg-P, Zn-Mg and Zn-P assemblies. Significantly higher content of Al was found in males of harbour porpoises.     

Oxidation of [Fe(CN)6]4- and reduction of [Fe(CN)6]3- in VUV-irradiated aqueous solutions

Vacuum ultraviolet (VUV) photolysis is one of the straightforward alternatives method among the advanced oxidation processes (AOPs) for the elimination of pollutants from water and air. The VUV photolysis of water produces hydroxyl radicals and hydrogen atoms, which have widely different oxidation and reduction abilities. In this work the oxidation and reduction properties of VUV-irradiated solutions were compared by investigating the reduction of [Fe(CN)6]3- and the oxidation of [Fe(CN)6]4-. The rate of oxidation of [Fe(CN)6]3- was found to be practically the same as the reduction rate of [Fe(CN)6]4- in the irradiated oxygen-free solutions under identical conditions. Dissolved oxygen strongly influences the redox properties of this system.     

Arsenic in drinking water and mortality in the Southern Great Plain,Hungary

Arsenic distribution has been found in drinking waters. A connection between arsenic and other constituents of water was determined. Close positive correlation was found between arsenic and humic substances over most of the study area. In two smaller areas, there was no correlation between arsenic and humic substances. In these waters, the arsenic distribution is not controlled by organic matter, but by other factors which need further investigations.Examination of mortality in the populations consuming water containing levels of arsenic above and below that permitted did not show any significant differences in standardised mortality ratio (SMR) from all causes of death for both male and female. The SMR from the main causes of death — diseases of the circulatory system and neoplasms — shows controversial results for males and females.     

Adsorption of propisochlor on soils and soil components equation for multi-step isotherms

Static equilibrium measurements were performed for the study of propisochlor on three different kinds of soils at pH = 7.0 at 25 degrees C. The concentration of herbicide was changed from 30 to 300 mumol/l. The obtained two-step adsorption isotherms cannot be evaluated by using the Freundlich or Langmuir equations. New equation has been derived by making use of the usual mass balance and equilibrium relationships of the adsorption and by considering the possibility of the formation of associates of the hydrophobic solute molecules. The characteristic model parameters of each step of the adsorption isotherm were estimated for the studied systems by a non-linear least square regression. The calculated curves fit well to the experimentally obtained two-step isotherms and the parameters of the model can be used for the characterization of the pesticide-soil interactions and consequently the mobility of the propisochlor in soil/water systems.