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The ratio of clay content to total organic carbon content is a useful parameter to predict adsorption of the herbicide butachlor in soils Полный текст
2008
Liu, Z. | He, Y. | Xu, J. | Huang, P. | Jilani, G.
Thirteen soils collected from 11 provinces in eastern China were used to investigate the butachlor adsorption. The results indicated that the total organic carbon (TOC) content, clay content, amorphous Fe2O3 content, silt content, CEC, and pH had a combined effect on the butachlor sorption on soil. Combination of the data obtained from the 13 soils in the present study with other 23 soil samples reported by other researchers in the literature showed that Koc would be a poor predictive parameter for butachlor adsorption on soils with TOC content higher than 4.0% and lower than 0.2%. The soils with the ratio of clay content to TOC content (RCO) values less than 60 adsorbed butachlor mainly by the partition into soil organic matter matrix. The soils with RCO values higher than 60 apparently adsorbed butachlor by the combination of the partition into soil organic matter matrix and adsorption on clay surface. The relative importance of organic matter and clay in butachlor adsorption in soil will depend on the ratio of clay content to total organic carbon content.
Показать больше [+] Меньше [-]Long-term study of palladium in road tunnel dust and sewage sludge ash Полный текст
2008
Leopold, K. | Maier, M. | Weber, S. | Schuster, M.
The present work summarizes data about palladium contents of road tunnel dust from 1994 to 2007 and sewage sludge ash from 1972 to 2006. Since palladium is emitted from automotive catalytic converters as elemental particles, road dust is quiet useful to study traffic-related Pd emissions. Very high Pd values of up to 516 μg Pd kg−1 were found in the road dust samples collected in 2007. Heavy metals of all urban emissions, also dental practice effluent, are enriched in sewage sludge ash and thus this matrix is useful for the documentation of palladium emission caused by the use of Pd alloys in dental medicine. In sewage sludge ash highest Pd contents of maximum 460 μg Pd kg−1 were found in the years 1986–1997. In both matrices correlations of Pd content to Pd demand of industry are discussed. This work reveals the link between intensified industrial Pd use and Pd content in according environmental samples.
Показать больше [+] Меньше [-]Field and laboratory simulations of storm water pulses: Behavioural avoidance by marine epifauna Полный текст
2008
Roberts, D.A. | Johnston, E.L. | Muller, S. | Poore, A.G.B.
Epifaunal communities associated with macroalgae were exposed to storm water pulses using a custom made irrigation system. Treatments included Millipore® freshwater, freshwater spiked with trace metals and seawater controls to allow for the relative importance of freshwater inundation, trace metals and increased flow to be determined. Experimental pulses created conditions similar to those that occur following real storm water events. Brief storm water pulses reduced the abundance of amphipods and gastropods. Freshwater was the causative agent as there were no additional effects of trace metals on the assemblages. Laboratory assays indicated that neither direct nor latent mortality was likely following experimental pulses and that epifauna readily avoid storm water. Indirect effects upon epifauna through salinity-induced changes to algal habitats were not found in field recolonisation experiments. Results demonstrate the importance of examining the effects of pulsed contaminants under realistic exposure conditions and the need to consider ecologically relevant endpoints. Brief storm water pulses trigger avoidance response in mobile epifauna due to the inundation of freshwater.
Показать больше [+] Меньше [-]Allocation plasticity and plant–metal partitioning: Meta-analytical perspectives in phytoremediation Полный текст
2008
Audet, Patrick | Charest, Christiane
In this meta-analysis of plant growth and metal uptake parameters, we selected 19 studies of heavy metal (HM) phytoremediation to evaluate trends of allocation plasticity and plant–metal partitioning in roots relative to shoots. We calculated indexes of biomass allocation and metal distribution for numerous metals and plant species among four families of interest for phytoremediation purposes (e.g. Brassicaceae, Fabaceae, Poaceae, and Solanaceae). We determined that plants shift their biomass and distribute metals more to roots than shoots possibly to circumvent the challenges of increasing soil-HM conditions. Although this shift is viewed as a stress-avoidance strategy complementing intrinsic stress-tolerance, our findings indicate that plants express different levels of allocation plasticity and metal partitioning depending on their overall growth strategy and status as ‘fast-grower’ or ‘slow-grower’ species. Accordingly, we propose a conceptual model of allocation plasticity and plant–metal partitioning comparing ‘fast-grower’ and ‘slow-grower’ strategies and outlining applications for remediation practices. This meta-analysis has revealed a shift in plant biomass and metal distribution from shoots to roots possibly to protect vital functions when subjected to metal stress.
Показать больше [+] Меньше [-]Levels and bioaccumulation of organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs) in fishes from the Pearl River estuary and Daya Bay, South China Полный текст
2008
Guo, L. | Qiu, Y. | Zhang, G. | Zheng, G.J. | Lam, P.K.S. | Li, Xunjing
Fifty fish samples were collected from the Pearl River estuary (PRE) and Daya Bay, South China and were analyzed for DDTs, HCHs, chlordanes and polybrominated biphenyl ethers (PBDEs). Except the high concentrations of DDT observed in fishes, the concentrations of HCHs, chlordanes and PBDEs were low when compared to other regions. BDE-47 was the predominant PBDE congener and the BDE-209 concentrations were relatively low, despite its high concentration in surface sediments. The absence of significant increase of DDT, HCH, chlordane and PBDE concentrations towards higher δ15N values, as well as the lack of a significant correlation (p < 0.1) between log concentrations (lipid normalized) and δ15N, may indicate a weak biomagnification of these chemicals in the food webs. Good agreement was observed between their concentrations and lipid contents of the organisms. Bioconcentration was suggested to be responsible for the accumulation of OCPs and PBDEs in the lower trophic organisms in the studied subtropical waters. Bioconcentration was suggested to be responsible for the accumulation of OCPs and PBDEs in the lower trophic organisms of subtropical waters.
Показать больше [+] Меньше [-]Slow growth of Empetrum nigrum in industrial barrens: Combined effect of pollution and age of extant plants Полный текст
2008
Zverev, Vitali E. | Zvereva, Elena L. | Kozlov, Mikhail V.
We studied the impact of industrial pollution on population demography (age structure), growth and reproduction of crowberry, Empetrum nigrum L. Crowberry growing in severely polluted sites near non-ferrous smelters (at Harjavalta, Monchegorsk and Nikel) was on average twice as old as in unpolluted habitats, as indicated by the number of annual rings at root collar. Shoot length decreased both with plant ageing and due to pollution impact, while neither the proportion of generative plants nor berry production was affected by pollution or plant age. Our results suggest that death of the extant individuals of E. nigrum near the non-ferrous smelters is to a large extent explained by age-related damage of the main stem accelerated by pollution. Since vegetative propagation, seed germination and seedling establishment are hampered by soil toxicity, E. nigrum populations near the smelters continue to decline with ageing in spite of the gradual decline of emissions. Both older age of crowberry in heavily polluted sites and pollution-induced environmental disturbance contributed to slower growth, but had no effect on fructification.
Показать больше [+] Меньше [-]Simultaneous monitoring of profiles of polycyclic aromatic hydrocarbons in contaminated air with semipermeable membrane devices and spruce needles Полный текст
2008
Zhu, Xiuhua | Pfister, Gerd | Henkelmann, Bernhard | Kotalik, Jarmila | Bernhöft, Silke | Fiedler, Stefan | Schramm, Karl-Werner
Gaseous emissions of combusted electronic scrap, PVC, carpet and wood were monitored for polycyclic aromatic hydrocarbons (PAHs) by simultaneous use of semipermeable membrane devices (SPMDs) and shoots of spruce needles (Picea abies). It was found that phenanthrene, acenaphthylene and fluorene were the dominating PAHs in all samples. SPMDs and needles mainly sequestered PAH associated with the vapor phase. Particle-bound PAHs were only detected in small amounts, at which the needles tended to uptake more of these compounds in comparison to the SPMDs. Nevertheless, the logarithm of the concentrations of PAHs analyzed in both passive samplers after the same sampling period exhibited a significant linear correlation with correlation coefficients larger than 0.8073. SPMDs and spruce needles can complement each other in passive air sampling for compounds with a preference to the gas phase rather than aerosols.Relationship of PAHs in SPMDs and spruce needles at the same sampling time was found.
Показать больше [+] Меньше [-]Metals in particle-size fractions of the soils of five European cities Полный текст
2008
Ajmone-Marsan, F. | Biasioli, M. | Kralj, T. | Grčman, H. | Davidson, C.M. | Hursthouse, A.S. | Madrid, L. | Rodrigues, S.
Soils from Aveiro, Glasgow, Ljubljana, Sevilla and Torino have been investigated in view of their potential for translocation of potentially toxic elements (PTE) to the atmosphere. Soils were partitioned into five size fractions and Cr, Cu, Ni, Pb and Zn were measured in the fractions and the whole soil. All PTE concentrated in the <10 μm fraction. Cr and Ni concentrated also in the coarse fraction, indicating a lithogenic contribution. An accumulation factor (AF) was calculated for the <2 and <10 μm fraction. The AF values indicate that the accumulation in the finer fractions is higher where the overall contamination is lower. AF for Cr and Ni are particularly low in Glasgow and Torino. An inverse relationship was found between the AF of some metals and the percentage of <10 μm particles that could be of use in risk assessment or remediation practices.
Показать больше [+] Меньше [-]Biomonitors and the assessment of ecological impacts: Distribution of herbivorous epifauna in contaminated macroalgal beds Полный текст
2008
Roberts, David A. | Johnston, Emma L. | Poore, Alistair G.B.
We determined metal contents of co-occurring algae Padina crassa and Sargassum sp. in Port Jackson (Australia), and relationships between metal levels and the abundance of epifaunal amphipods. Copper, lead and zinc concentrations were amongst the highest yet recorded in these algae. Copper, manganese and lead concentrations were far greater in P. crassa than Sargassum sp., possibly due to the low growth of P. crassa in proximity to contaminated sediments. However, in manipulative experiments the proximity of algae to sediments did not explain these differences. The abundance of herbivorous amphipods correlated negatively with the copper content of P. crassa, but not with the lower concentrations in Sargassum sp. The greater contamination of P. crassa led to patchy distributions of metals in algal beds and recolonisation experiments showed Sargassum sp. acts as a refuge from contaminants for epifauna. The contamination of macroalgae may pose threats to epifauna in harbours around the world. The accumulation of metals by macroalgae may pose ecological threats to herbivorous epifauna in ports and harbours worldwide.
Показать больше [+] Меньше [-]Phthalate esters (PAEs): Emerging organic contaminants in agricultural soils in peri-urban areas around Guangzhou, China Полный текст
2008
Zeng, Feng | Cui, Kunyan | Xie, Zhiyong | Wu, Linuo | Liu, Min | Sun, Guoquan | Lin, Yujun | Luo, Danling | Zeng, Zunxiang
This study reports the first data on the concentrations and distribution of phthalate esters (PAEs) in the agricultural soils from the peri-urban areas of Guangzhou city. Σ16PAEs concentrations ranged from 0.195 to 33.6 μg g−1-dry weight (dw). Elevated levels of PAEs were recorded in the vegetable fields located next to the urban districts, and a decreasing trend exists following the distance away from the urban center. Diisobutyl phthalate (DiBP), Di-n-butyl phthalate (DnBP), and Di(2-ethylhexyl) phthalate (DEHP) dominated the PAEs in the agricultural soils. Significant relationship (correlation coefficient R2 = 0.85, p < 0.01, n = 40) was present between the accumulation of PAEs and total organic carbons in agricultural soils. In addition, both pH and texture of soils are found to be important factors affecting the level of PAEs. This study shows that the agricultural soils in the peri-urban area of Guangzhou city were moderately polluted by PAEs. PAEs are determined in agricultural soils at high concentration levels, which imply a potential risk for the food chain.
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