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101.
Phosphorus (P) fertilizer is essential for food production and is a limiting factor in crop yields. However, the role of P in the eutrophication of surface water has long been recognised. During recent years, the input of P from agriculture to surface waters has increased and has been the focus for strategies aimed at mitigating diffuse P losses. As not all forms of P have the same availability, it is important to know the main forms of phosphorus in biowastes, and hence to develop fractionation schemes. The standards, measurements, and testing (SMT) procedure for phosphorus fractionation in freshwater sediments, developed within the framework of the Standards, Measurements, and Testing Program of the European Commission, was applied to 15 biowastes used frequently in agriculture, to obtain total P, inorganic and organic P, apatite P, and non-apatite inorganic P. The Hedley method was applied to determine the water-soluble phosphorus (WSP) in all the biowastes. In addition, the aluminium, calcium, and iron concentrations were quantified and related to the WSP. The results confirm the applicability of the SMT protocol to all kinds of waste usually applied in agriculture. The SMT protocol revealed the existence of large amounts of inorganic P and non-apatite inorganic P, the most-available forms of P for all the biowastes. The comparison of the data for total P (SMT protocol) and WSP (Huang protocol) does not show a good linear relationship between these parameters. Instead, the relationship between [aluminium+calcium+iron] and WSP is a better indication of the availability of P.  相似文献   
102.
A composted biosolid from wastewater treatment was added to soils of two public parks of Sevilla, and successive samples were taken during one year. In one of the parks, a second addition of biosolid was carried out after the first year. The soil contents in metals (pseudo-total) and their plant-available and oral bio-accessible fractions were significantly altered when the soils were amended with biosolid. Increase of the bio-accessible metal contents represents a deterioration of the environmental quality of recreational areas, where hand-to-mouth transfer of pollutants to children is likely to occur, although part of the metals added might be leached by rainfall or irrigation. The limits established in several countries for metal contents of soils in recreational areas are often exceeded after application of the biosolid. A careful study of the metal contents of recycled wastes is thus recommended before being used for green area maintenance.  相似文献   
103.

Introduction  

Many previous studies revealed a high ability of mushrooms to accumulate heavy metals from environment. This paper concerns the capacity of some wild macromycetes belonging to Russula genus to accumulate heavy metals in natural condition of pH (between 6.5 and 6.8) and the pattern of metal translocation in the fruiting body.  相似文献   
104.

Purpose  

Solid waste incineration has recently attracted much attention because the combustion process involved produces highly toxic organohalogen contaminants such as dioxin-like polychlorinated biphenyls (DL-PCBs) present in fly ash. This has raised the need for simple, rapid, accurate methods for monitoring PCBs in ash samples.  相似文献   
105.
The purpose of the present study was to research the sublethal and/or lethal effects produced by the exposure of fish and shellfish to the γ isomer of lindane, γ-hexachlorocyclohexane (γ-HCH). The teleostean fish Sparus aurata and the shellfish Crassostrea angulata and Scrobicularia plana, were exposed to 16 μ g/L of lindane for 15 days. Samples of different fish (liver, kidney and gills) and shellfish (gills, gut, digestive gland and mantle) tissues were extracted and processed for histopathological observations. Although mortality was not detected during the bioassay, sublethal effects (histopathological alterations) were observed. Vacuolization in the liver cells and lamellar fusion in gills from exposed fish were observed. Disorganization of normal gill structure, epithelial desquamation with the disappearance of apical ciliature in intestine, and inflammatory response in mantle from exposed shellfish were also observed. Thus, it can be concluded that the lindane concentration employed in the present research did not produce lethal effects in the exposed organisms but it caused sublethal effects. Lindane has time-dependent multiple toxic effects in S. aurata, C. angulata and S. plana, which were more severe at the end of the experimental time. The toxicological implications arising from these results are subjects for further multiconcentration tests dealing with lethal responses (mortality) or with sublethal responses (cellular/molecular biomarkers) of the aforementioned species.  相似文献   
106.
Influence of different parameters on biosurfactant (BS) activity was carried out on strains that were isolated from the polychaetes Megalomma claparedei, Sabella spallanzanii and Branchiomma luctuosum and additional 30 strains that were previously identified as potential BS producers from crude oil enrichments of the same polychaete specimens. The selection of BS-producing strains from polychaete natural samples was carried out by using standard screening tests. The BS activity by each isolate was evaluated for the effect of salinity and temperature on emulsion production and surface tension reduction, during incubation in mineral medium supplemented with tetradecane or diesel oil. All isolates showed a similar time course of BS activity, and the latter was more influenced by salinity rather than temperature. Some of the BS producers belonged to genera that have not (i.e. Citricoccus, Cellulophaga, Tenacibaculum and Maribacter) or have poorly been (Psychrobacter, Vibrio, and Pseudoalteromonas) reported as able to produce BSs. This is remarkable as some of them have previously been detected in hydrocarbon-enriched samples. Results confirm that filter-feeding polychaetes are an efficient source for the isolation of BS producers.  相似文献   
107.
A simplified dynamic model for the activated sludge process with high-strength wastewaters is presented. The model is based on activated sludge models and predicts effluent chemical oxygen demand concentration using only four parameters. Experimental data for testing the model were obtained in an activated sludge plant using flax retting wastewater. The proposal of the model is described: mass balance to the system, selection of variables and behaviour of the theoretical values versus experimental results.  相似文献   
108.
A PAH contaminated river floodplain soil was separated according to grain size and density. Coal and coal-derived particles from coal mining, coal industry and coal transportation activities were identified by organic petrographic analysis in our samples. Distinct concentrations of PAHs were found in different grain size and density fractions, however, similar distribution patterns of PAHs indicated similar sources. In addition, although light fractions had the mass fraction by weight of less than 5%, they contributed almost 75% of the total PAHs in the soil. PAH concentrations of all sub fractions showed positive correlation with their TOC contents. Altogether, coal and coal-derived particles that were abundant in light fractions could be the dominant geosorbents for PAHs in our samples.  相似文献   
109.
Foramina parietalia permagna (FPP) is an extremely uncommon congenital defect, inherited as an autosomal dominant condition. Its characteristics are two symmetrical orifices in the parietal bones (not of fixed size) on both sides of the midline. This defect does not affect either the psychic or the physical development of the affected person. This paper describes the sonographic appearance of FPP in utero as an enlargement of the posterior fontanelle.  相似文献   
110.
Chlorobenzene bioconcentration factors for Scenedesmus spp measured by batch equilibration, increased with temperature between 4.5 and 27.6 °C. A thermodynamic analysis suggests that the bioconcentration is driven by an entropy gain. Slopes of LogBCF-logKow relationships increased with temperature. These results agree with earlier reports for the analogous bioconcentration to fish.  相似文献   
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