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[Character of pollution and longtime variations of Tamis river water quality]
1997
Cukic, Z. (Univerzitet u Novom Sadu, Novi Sad (Yugoslavia). Prirodno-matematicki fakultet, Institut za hemiju) | Kilibarda, P. | Kojcic, K. | Jovanovic, D.
In this paper, the results of statistical analysis of then years water quality data of Tamis river at the Romanian-Yugoslav border ("Jasa Tomic" Control Station) are presented. Following changes of analyzed water quality parameters at the Romanian-Yugoslav border a strong trend of deterioration has been observed during analyzed period. Because of periodical accidentally high organic content (COD, BOD) and concentration of ammonia and organic nitrogen in river water, it is concluded that upstream discharging of farm waste waters was the main reason of deterioration of water quality along the Yugoslav part of Tamis river.
Afficher plus [+] Moins [-]Effects of preparatory stands on forest site restoration
2002
Remes, J. | Podrazsky, V. (Czech University of Agriculture, Prague (Czech Republic). Faculty of Forestry)
The main aims of the preparatory stands in air pollution areas are growth development, successfull dynamics of the plants and fast creation of the stand microclimate with favourable effect on soil conditions. This process is documented by height and diameter increment. The results confirm different growth dynamics of the particular species. Larch is the species with the best growth dynamics of selected species on experimental plots. On the other hand, beech is the worst species for reforestation in this condition. One of the causes could be damage by frost
Afficher plus [+] Moins [-]The potential ecological risk of multiwall carbon nanotubes was modified by the radicals resulted from peroxidase-mediated tetrabromobisphenol A reactions
2017
Lu, Kun | Huang, Qingguo | Xia, Tian | Chang, Xiaofeng | Wang, Peng | Gao, Shixiang | Mao, Liang
Extensive studies have been conducted on the environmental degradation of multiwall carbon nanotubes (MWCNTs), but primarily focused on the extent and rate of MWCNTs mineralization. Few studies have explored possible structural changes that may occur to MWCNTs during natural or engineered processes. We systematically examined MWCNTs in oxidative coupling reactions in the presence of a common contaminant tetrabromobisphenol A (TBBPA). MWCNTs was modified by the radicals of TBBPA resulting from peroxidase-mediated coupling reaction. Interactions between TBBPA radicals and MWCNTs were definitely confirmed by analyzing the characteristic mass spectrometry response of bromine in TBBPA and the structures of MWCNTs. After reaction with TBBPA radicals for 60 min, the content of bromine contained in MWCNTs was 6.84(±0.12)%, a quantity equivalent to a 501.65(±2.19) mg loading of TBBPA per gram MWCNTs. Modified MWCNTs had better stability and smaller sizes than that of MWCNTs and TBBPA-adsorbed MWCNTs. Assessment using zebrafish embryos revealed that the modified MWCNTs passed through the chorion and entered the embryo inducing acute toxicity, while the MWCNTs/TBBPA-adsorbed MWCNTs was trapped by chorion. These findings indicated that MWCNTs was modified in peroxidase-mediated coupling reactions, and suggested that such modifications may have an influence on the ecological risks of MWCNTs.
Afficher plus [+] Moins [-]Simulated degradation of biochar and its potential environmental implications
2013
Liu, Zhaoyun | Demisie, Walelign | Zhang, Mingkui
A simulated oxidation technique was used to examine the impacts of degradation on the surface properties of biochar and the potential implications of the changes in biochar properties were discussed. To simulate the short- and long-term environmental degradation, mild and harsh degradation were employed. Results showed that after mild degradation, the biochar samples showed significant reductions in surface area and pore volumes. After harsh degradation, the biochar samples revealed dramatic variations in their surface chemistry, surface area, pore volumes, morphology and adsorption properties. The results clearly indicate that changes of biochar surface properties were affected by biochar types and oxidative conditions. It is suggested that biochar surface properties are likely to be gradually altered during environmental exposure. This implies that these changes have potential effects for altering the physicochemical properties of biochar amended soils.
Afficher plus [+] Moins [-]Development of a test-tube stress-ethylene bioassay for detecting phytotoxic gases | Development of a test-tube stress-ethylene bioassay for detecting phytotoxic gases
1982
Craker, L. E. | Fillatti, J. J.
A rapid, quantitative bioassay for detecting phytotoxic air pollutants has been developed. The technique uses wheat Triticum aestivum L. or tomato Lycopersicon esculentum L., seedlings growing on an agar medium in test-tubes. The seedlings are exposed to a pollutant in the test-tube and stress-ethylene induced by the pollutant is quantitatively measured by gas chromatography. Increases in ethylene production from seedlings exposed to a phytotoxic air pollutant as compared with controls not exposed to pollutants were related to the pollutant concentration.
Afficher plus [+] Moins [-]Forests health status as the result of environmental impacts and forestry interventions
2002
Hocevar, M. | Mavsar, R. | Kovac, M. (Slovenian Forestry Institute, Ljubljana (Slovenia))
The analysis of the latest results along with the change analysis reveals that the conditions of Slovenia's forest are considerably stable and that the process of decline has not progressed with the intensity, that had been predicted in the early eighties. Quite favourable conditions are due to prompt actions (selection and sanitary cutting) in the field
Afficher plus [+] Moins [-]Polychlorinated biphenyls and its potential role in endometriosis
2017
Yao, Mengyun | Hu, Tingting | Wang, Yinfeng | Du, Yongjiang | Hu, Changchang | Wu, Ruijin
With the progress of global industrialization and environmental deterioration, the relationship between human health and the living environment has become an increasing focus of attention. Polychlorinated biphenyls (PCBs, including dioxin-like polychlorinated biphenyls and non-dioxin-like polychlorinated biphenyls), as part of the organic chlorine contaminants, have been suspected as playing a role in the etiopathogenesis of endometriosis. Several population-based studies have proposed that exposure to PCBs may increase the risk of developing endometriosis, while some epidemiological studies have failed to find any association between PCBs and endometriosis. The purpose of this review is to discuss the potential pathophysiological relationship between endometriosis and PCBs with a focus on both dioxin-like polychlorinated biphenyls and non-dioxin-like polychlorinated biphenyls.
Afficher plus [+] Moins [-]Characterising the exchangeability of phenanthrene associated with naturally occurring soil colloids using an isotopic dilution technique
2015
Tavakkoli, Ehsan | Juhasz, Albert | Donner, Erica | Lombi, Enzo
The association of polycyclic aromatic hydrocarbons (PAHs) with inorganic and organic colloids is an important factor influencing their bioavailability, mobility and degradation in the environment. Despite this, our understanding of the exchangeability and potential bioavailability of PAHs associated with colloids is limited. The objective of this study was to use phenanthrene as a model PAH compound and develop a technique using 14C phenanthrene to quantify the isotopically exchangeable and non-exchangeable forms of phenanthrene in filtered soil water or sodium tetraborate extracts. The study was also designed to investigate the exchangeability of colloidal phenanthrene as a function of particle size. Our findings suggest that the exchangeability of phenanthrene in sodium tetraborate is controlled by both inorganic and organic colloids, while in aqueous solutions inorganic colloids play the dominant role (even though coating of these by organic matter cannot be excluded). Filter pore size did not have a significant effect on phenanthrene exchangeability.
Afficher plus [+] Moins [-]Managing urban nutrient biogeochemistry for sustainable urbanization
2014
Lin, Tao | Gibson, Valerie | Cui, Shenghui | Yu, Chang-Ping | Chen, Shaohua | Ye, Zhilong | Zhu, Yong-Guan
Urban ecosystems are unique in the sense that human activities are the major drivers of biogeochemical processes. Along with the demographic movement into cities, nutrients flow towards the urban zone (nutrient urbanization), causing the degradation of environmental quality and ecosystem health. In this paper, we summarize the characteristics of nutrient cycling within the urban ecosystem compared to natural ecosystems. The dynamic process of nutrient urbanization is then explored taking Xiamen city, China, as an example to examine the influence of rapid urbanization on food sourced nitrogen and phosphorus metabolism. Subsequently, the concept of a nutrient footprint and calculation method is introduced from a lifecycle perspective. Finally, we propose three system approaches to mend the broken biogeochemical cycling. Our study will contribute to a holistic solution which achieves synergies between environmental quality and food security, by integrating technologies for nutrient recovery and waste reduction.
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