Phytoextraction crop disposal--an unsolved problem

Several methods of contaminated crop disposal after phytoextraction process (composting, compaction, incineration, ashing, pyrolysis, direct disposal, liquid extraction) have been described. Advantages and disadvantages of methods are presented and discussed. Composting, compaction and pyrolysis are the pretreatment steps, since significant amount of contaminated biomass will still exist after each of the process. Four methods of final disposal were distinguished: incineration, direct disposal, ashing and liquid extraction. Among them, incineration (smelting) is proposed as the most feasible, economically acceptable and environmentally sound.     

Uptake of cadmium by Stichococcus bacillaris

The uptake of cadmium by the green alga $\text{Stichococcus bacillaris}$ was studied. It was found that about 80% of the uptake was due to adsorption, and about 20% to energy-dependent transport. Investigations on the relationship between the sorption of cadmium and the equilibrium concentration (Ce) revealed that the alga cells are saturated at Ce20mg Cd/1.     

Hepatotoxicity of monobromobenzene and hexabromobenzene: effects of repeated dosage in rats

The aim of the study was to determine whether monobromobenzene (BB) and hexabromobenzene (HBB) administered repeatedly (for 28 days) to female rats resulted in disturbances of heme synthesis. 5-Aminolevulinate dehydratase (ALA-D) and 5-aminolevulinate synthase (ALA-S) activities were slightly changed and the concentration of glutathione increased. The excretion of 5-aminolevulinic acid (ALA-U) in urine after all doses of BB and HBB increased already in the first week. After BB administration, increased excretion of coproporphyrins was detected only at the highest dose. The increased excretion of coproporphyrins following the administration of HBB could be observed already at the lowest dose (15 mg/kg). The excretion of uroporphyrins increased after two higher doses (75 and 375 mg/kg) in the fourth week of exposure. HBB also caused elevation of microsomal P450 level. The data suggest porphyrogenic activity of HBB; whereas in the case of BB we cannot exclude that elevated excretion of ALA-U resulted from kidney impairment.     

Possibilities for the efficient utilisation of spent geothermal waters

Waters located at greater depths usually exhibit high mineral content, which necessitates the use of closed systems, i.e. re-injecting them into the formation after recovering the heat. This significantly reduces investment efficiency owing to the need to drill absorption wells and to perform anti-corrosion and anti-clogging procedures. In this paper, possibilities for the efficient utilisation of cooled geothermal waters are considered, particularly with respect to open or mixed geothermal water installations. Where cooled water desalination technologies are used, this allows the water to be demineralised and used to meet local needs (as drinking water and for leisure purposes). The retentate left as a by-product of the process contains valuable ingredients that can be used for balneological and/or leisure purposes. Thus, the technology for desalinating spent geothermal waters with high mineral content allows improved water management on a local scale and makes it possible to minimise the environmental threat resulting from the need to dump these waters into waterways or surface water bodies and/or inject them into the formation. The paper is concerned with Polish geothermal system and provides information about the parameters of Polish geothermal waters.     

Plutonium concentrations in waters from the southern Baltic Sea and their distribution in cod (Gadus morhua) skin and gills

The concentrations of (238)Pu and (239+240)Pu in water samples and suspended particulate fractions, as well as in colloidal fraction from the southern Baltic Sea are presented. The (239+240)Pu concentration in surface seawater samples fall within range from 5.2 mBq.m(-3) for Gdańsk Bay to 150 mBq.m(-3) for Pomeranian Bay, most of which (from 52 to 96%) constituted filterable forms (相似文献   

Response of mosses to the heavy metal deposition in Poland--an overview

Concentrations of heavy metals (Cd, Cr, Cu, Fe, Ni, Pb, Zn) in Pleurozium schreberi (Brid.) Mitt., a common moss species, were used to indicate relative levels of atmospheric deposition in Poland in the years 1975-1998. Spatial and temporal differences in the heavy metal concentrations in mosses were found. The highest concentration of heavy metals was recorded in the moss samples from the southern, most industrialised part of the country, and the lowest from north-eastern Poland. A significant decrease of heavy metals over 20 years (1975-1998) was found.     

The influence of pH on cadmium toxicity to the green alga Stichococcus bacillaris and on the cadmium forms present in the culture medium

Cadmium toxicity to the green alga Stichococcus bacillaris was investigated in media of pH 3-9. A significant decrease of cadmium toxicity occurred in both the acidic and alkaline ranges of pH. In media of pH 3 and 9, cadmium did not affect the dry mass content substantially. Maximum toxicity of cadmium was noticed at pH 6-7. Voltametric investigations showed a significant effect of pH on electrochemically measured cadmium content in the culture media. Hydrolysis of the medium components and formation of cadmium complexes with OH(-) ions caused a considerable decrease in amounts of electrochemically measured cadmium in the alkaline range of pH.     

Landscape trajectory of natural boreal forest loss as an impediment to green infrastructure

Loss of natural forests by forest clearcutting has been identified as a critical conservation challenge worldwide. This study addressed forest fragmentation and loss in the context of the establishment of a functional green infrastructure as a spatiotemporally connected landscape-scale network of habitats enhancing biodiversity, favorable conservation status, and ecosystem services. Through retrospective analysis of satellite images, we assessed a 50- to 60-year spatiotemporal clearcutting impact trajectory on natural and near-natural boreal forests across a sizable and representative region from the Gulf of Bothnia to the Scandinavian Mountain Range in northern Fennoscandia. This period broadly covers the whole forest clearcutting period; thus, our approach and results can be applied to comprehensive impact assessment of industrial forest management. The entire study region covers close to 46,000 km² of forest-dominated landscape in a late phase of transition from a natural or near-natural to a land-use modified state. We found a substantial loss of intact forest, in particular of large, contiguous areas, a spatial polarization of remaining forest on regional scale where the inland has been more severely affected than the mountain and coastal zones, and a pronounced impact on interior forest core areas. Salient results were a decrease in area of the largest intact forest patch from 225,853 to 68,714 ha in the mountain zone and from 257,715 to 38,668 ha in the foothills zone, a decrease from 75% to 38% intact forest in the inland zones, a decrease in largest patch core area (assessed by considering 100-m patch edge disturbance) from 6114 to 351 ha in the coastal zone, and a geographic imbalance in protected forest with an evident predominance in the mountain zone. These results demonstrate profound disturbance of configuration of the natural forest landscape and disrupted connectivity, which challenges the establishment of functional green infrastructure. Our approach supports the identification of forests for expanded protection and conservation-oriented forest landscape restoration.