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Radiocaesium in Cortinarius spp. mushrooms in the regions of the Reggio Emilia in Italy and Pomerania in Poland
2016
Zalewska, Tamara | Cocchi, Luigi | Falandysz, Jerzy
Activity concentrations of ¹³⁴Cs and ¹³⁷Cs have been determined in 23 species of mushrooms of the genus Cortinarius (59 individual samples) collected from the Reggio Emilia in Italy 1992–1999 and in 4 species (16 composite samples and 413 individuals) from the Pomerania region in Poland from 1996 to 2015. Across all the Cortinarius species from the Reggio Emilia, the activity concentrations were relatively high in Cortinarius alboviolaceus, Cortinarius duracinus, Cortinarius orellanus, Cortinarius rapaceus, and Cortinarius subannulatus, in which ¹³⁷Cs was at 10,000 ~ 100,000 Bq kg⁻¹ dry biomass (db) in 1994. Smaller activity concentrations were found in Cortinarius bivelus, Cortinarius bulliardii, Cortinarius cotoneus, Cortinarius largus, Cortinarius lividoviolaceus, Cortinarius purpureus, Cortinarius rufo-olivaceus, Cortinarius torvus, and Cortinarius venetus with levels at 1000 ~ 6000 Bq kg⁻¹ db from 1992 to 1994, and further in Cortinarius anserinus, Cortinarius auroturbinatus, C. largus, Cortinarius praestans, Cortinarius purpurascens, Cortinarius scaurus, Cortinarius sebaceous, Cortinarius talus, and Cortinarius variecolor with activity concentrations at 100 ~ 600 Bq kg⁻¹ db in 1994. All the data were calculated for dehydrated fungal material corrected back to the exact date samples of collection. The greatest activity concentrations of ¹³⁷Cs both in Italy (1992–1999) and Poland (1996–2010) were found in the popular Cortinarius caperatus, confirming its very high capacity of radiocaesium accumulation. Besides ¹³⁷Cs, the isotope ¹³⁴Cs was detected in some species from the Reggio Emilia. An average calculated ratio of activities of ¹³⁴Cs to ¹³⁷Cs referenced to 1986 was equal to 0.38 in mushrooms from the Reggio Emilia, and this value slightly differ from that specific for Chernobyl fallout, which was 0.54. It was calculated that ¹³⁷Cs originating from Chernobyl accident constituted about 68 % of the total activity concentration of the isotope in Reggio Emilia in 1986, while as much as 32 % of ¹³⁷Cs in mushrooms were from the global fallout from nuclear bomb testing.
Show more [+] Less [-]Effects of dicyandiamide and acetylene on N2O emissions and ammonia oxidizers in a fluvo-aquic soil applied with urea
2016
Wang, Qing | Zhang, Li-Mei | Shen, Ju-Pei | Du, Shuai | Han, Li-Li | He, Ji-Zheng
Ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) are crucial for N₂O emission as they carry out the key step of nitrification. Dicyandiamide (DCD) and acetylene (C₂H₂) are typical nitrification inhibitors (NIs), while the comparative effects of these NIs on N₂O production and ammonia oxidizers’ (AOB and AOA) growth are unclear. Four treatments including a control, urea, urea + DCD, and urea + C₂H₂ were set up to investigate their effect of inhibiting soil nitrification, nitrification-related N₂O emission as well as the growth of ammonia oxidizers with a fluvo-aquic soil using microcosms for 28 days. N₂O emission and net nitrification rate increased after the application of urea, but were significantly restrained in urea + NI treatments, while C₂H₂ was more effective in reducing N₂O emission and nitrification rate than DCD. The abundance of AOB, which was significantly correlated with N₂O emission and net nitrification rate, was more inhibited by C₂H₂ than DCD. Furthermore, the application of urea in all the soils had little impact on the AOA community, while obvious shifts of AOB community structure were found compared with the control. All AOB sequences fell within Nitrosospira cluster 3, and the AOA community was clustered to group 1.1b. Collectively, it indicated that application of urea combined with NIs (DCD or C₂H₂) could potentially alter N₂O emission, mainly through regulating the growth of AOB but not AOA in this fluvo-aquic soil.
Show more [+] Less [-]Effects of bypass system on PCDD/F emission and chlorine circulation in cement kilns
2016
Zhan, Ming-Xiu | Fu, Jianying | Chen, Tong | Li Yeqing, | Zhang, Jiang | Li, Xiao-Dong | Yan, Jian-Hua | Buekens, Alfons
A bypass at the kiln inlet allows the effective reduction of alkali chloride cycles and thus perhaps affects the emission of PCDD/Fs. Effects of bypass system on PCDD/F emission and chlorine circulation were studied in two typical dry cement kilns with 5000 ton/day clinker capacity in China and named CK1 and CK2, respectively. Firstly, the emission level of PCDD/Fs with the operation of bypass system was estimated in CK1, to certify that bypass system has a perfect adaption to the cement kiln regarding the PCDD/F emission even with the refuse derived fuel (RDF) as the replacement of fuel. On the other hand, the operating conditions in the CK2 were scrutinised by monitoring the concentrations of SO₂, NH₃ and HCl. In addition, the characteristics of raw meal, clinker, bag filter ash and bypass ash were also investigated by Energy Dispersive Spectrometer (EDS), metal and chlorine analysis. The balance of chlorine showed that 18 % of the possible accumulated chlorine could be ejected from the cement kiln system when 2 % of kiln exhaust gas was extracted. Furthermore, the emission level of PCDD/Fs in the main flue gas also decreased from 0.037 ± 0.035 ng I-TEQ/Nm³ to 0.019 ± 0.007 ng I-TEQ/Nm³ with a reduction efficiency of 48.2 %. Most importantly, PCDD/F emission from the bypass system was proven to have rather minor effect on the total emission factor. The congener distributions of PCDD/Fs were also analysed in the flue gas and fly ash, before and after application of bypass system, to find cues to the formation mechanism.
Show more [+] Less [-]Screening beneficial rhizobacteria from Spartina maritima for phytoremediation of metal polluted salt marshes: comparison of gram-positive and gram-negative strains
2016
Paredes-Páliz, Karina I. | Caviedes, Miguel A. | Doukkali, Bouchra | Mateos-Naranjo, Enrique | Rodríguez-Llorente, Ignacio D. | Pajuelo, Eloísa
The aim of our work was the isolation and characterization of bacteria from the rhizosphere of Spartina maritima in the metal contaminated Odiel estuary (Huelva, SW Spain). From 25 strains, 84 % were identified as gram-positive, particularly Staphylococcus and Bacillus. Gram-negative bacteria were represented by Pantoea and Salmonella. Salt and heavy metal tolerance, metal bioabsorption, plant growth promoting (PGP) properties, and biofilm formation were investigated in the bacterial collection. Despite the higher abundance of gram-positive bacteria, gram-negative isolates displayed higher tolerance toward metal(loid)s (As, Cu, Zn, and Pb) and greater metal biosorption, as deduced from ICP-OES and SEM-EDX analyses. Besides, they exhibited better PGP properties, which were retained in the presence of metals and the ability to form biofilms. Gram-negative strains Pantoea agglomerans RSO6 and RSO7, together with gram-positive Bacillus aryabhattai RSO25, were selected for a bacterial consortium aimed to inoculate S. maritima plants in metal polluted estuaries for phytoremediation purposes.
Show more [+] Less [-]Level of contamination by metallic trace elements and organic molecules in the seagrass beds of Guadeloupe Island
2016
Bouchon, Claude | Lemoine, Soazig | Dromard, Charlotte | Bouchon-Navaro, Yolande
Seagrass bed ecosystems occupy the most important part of coastal shelf in the French West Indies. They also constitute nurseries for many invertebrates and fishes harvested by local fisheries. In Guadeloupe, coastal fish stocks are declining meanwhile several agroecosystems revealed to be heavily contaminated by pollutants (agricultural lands, rivers, mangroves, seagrass beds, and coral reefs). Considering these facts, a study of the contamination of seagrass beds (8000 ha) of the Grand Cul-de-Sac Marin (GCSM) bay was conducted on their sediments and marine phanerogams. The analyses concerned six metals (Cd, Cu, Hg, Pb, V, Zn), tributyltin, 18 polycyclic aromatic hydrocarbons (PAHs), eight polybrominated diphenyl ethers (PBDEs), 38 polychlorobiphenyls (PCBs), dithiocarbamates (CS2 residues), and 225 pesticide molecules.Overall, the level of contamination of the seagrass beds was low for both sediments and phanerogams. Metallic trace elements were the main pollutants but with higher concentrations recorded in coastal sites, and their distribution can be explained by the proximity of river mouths and current patterns. The level of contamination was lower in plants than in sediments. However, the level of contamination between these two compartments was significantly correlated. The conclusion of this study is that, unlike other coastal ecosystems of Guadeloupe such as mangroves, the seagrass beds in the GCSM present a low degree of pollution. The observed level of contaminants does not seem to threaten the role of nursery played by the seagrass beds and does not likely present a risk for the reintroduction of manatees.
Show more [+] Less [-]Early genotoxic response and accumulation induced by waterborne copper, lead, and arsenic in European seabass, Dicentrarchus labrax
2016
Canalejo, Antonio | Diaz-de-Alba, Margarita | Granado-Castro, M Dolores | Córdoba, Francisco | Espada-Bellido, Estrella | Galindo-Riaño, M Dolores | Torronteras, Rafael
Cu, Pb, and As, which are among the most abundant metals in the aquatic environment, are also among the most health-threatened by causing diverse cellular injuries. The aim of this study was to assess and compare the potential early induction of genotoxic effects after waterborne Cu, Pb, and As exposure in European seabass, Dicentrarchus labrax, a commercial widely cultured fish, using the micronucleus (MN) assay in peripheral blood erythrocytes. Fish were exposed under laboratory conditions to nominal solutions ranging 0–10 mg/L for 24 and 96 h. Furthermore, actual metal ion concentrations were measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES) or differential pulse anodic stripping voltammetry (DPASV) in water and four fish tissues differentially related to environmental exposition and metal accumulation, i.e. the gills, liver, muscle, and brain. Dose-dependent increases of micronuclei (MNi) frequency were observed after these very short exposures; based on measured metal concentrations in water, the genotoxic effect ordered as Cu > As > Pb. Significant genotoxic effect at 0.009 mg/L Cu, 0.57 mg/L Pb, and 0.01 mg/L As was seen. For Cu and Pb these are only slightly higher, but for As it is notably lower than the USEPA criteria of maximum concentration to prevent acute toxicity in aquatic organisms. Furthermore, genotoxicity was differentially related to metal accumulation. MNi frequency correlated positively with the content of Pb in all the organs, with the content of As in liver and gills and only with the content of Cu in the brain. In conclusion, our findings raised environmental concerns because these depicted a genotoxic potential of Cu, Pb, and As after a very short exposure to low but environmentally relevant concentrations, too close to regulatory thresholds. In addition, the MN test in D. labrax could be considered an early biomarker of genotoxicity induced by these metals in fish.
Show more [+] Less [-]Immobilization of heavy metals in electroplating sludge by biochar and iron sulfide
2016
Lyu, Honghong | Gong, Yanyan | Tang, Jingcshun | Huang, Yao | Wang, Qilin
Electroplating sludge (ES) containing large quantities of heavy metals is regarded as a hazardous waste in China. This paper introduced a simple method of treating ES using environmentally friendly fixatives biochar (BC) and iron sulfide (FeS), respectively. After 3 days of treatment with FeS at a FeS-to-ES mass ratio of 1:5, the toxicity characteristic leaching procedure (TCLP)-based leachability of total Cr (TCr), Cu(II), Ni(II), Pb(II), and Zn(II) was decreased by 59.6, 100, 63.8, 73.5, and 90.5 %, respectively. After 5 days of treatment with BC at a BC-to-ES mass ratio of 1:2, the TCLP-based leachability was declined by 35.1, 30.6, 22.3, 23.1, and 22.4 %, respectively. Pseudo first-order kinetic model adequately simulated the sorption kinetic data. Structure and morphology analysis showed that adsorption, electrostatic attraction, surface complexation, and chemical precipitation were dominant mechanisms for heavy metals immobilization by BC, and that chemical precipitation (formation of metal sulfide and hydroxide precipitates), iron exchange (formation of CuFeS₂), and surface complexation were mainly responsible for heavy metals removal by FeS. Economic costs of BC and FeS were 500 and 768 CNY/t, lower than that of Na₂S (940 CNY/t). The results suggest that BC and FeS are effective, economic, and environmentally friendly fixatives for immobilization of heavy metals in ES before landfill disposal.
Show more [+] Less [-]Heavy metals in sediments, soils, and aquatic plants from a secondary anabranch of the three gorges reservoir region, China
2016
Gao, Jun-min | Sun, Xiu-qian | Jiang, Wen-chao | Wei, Yun-mei | Guo, Jin-song | Liu, Yuanyuan | Zhang, Ke
We investigated the occurrence of cadmium (Cd), copper (Cu), chromium (Cr), nickel (Ni), lead (Pb), Znic (Zn), iron (Fe), manganese (Mn), and magnesium (Mg) in sediments, as well as in related soils and aquatic plants in the Liangtan River, a typical secondary anabranch of the Yangtze River in the Three Gorges Reservoir Region (TGRR) of China. We found that sediments accumulated more metals than soils and aquatic plants. Concentrations of the nine metals in sediments and soils followed the same sequence, while their concentrations in aquatic plants followed a different sequence. Potential adverse effects of contaminated sediments on benthic fauna were evaluated, and the results showed that the toxic effect on benthic organisms followed the sequence Zn > Ni > Cr > Cu > Cd > Pb. The potential ecological risk index analysis indicated that Cd in sediments had considerable ecological risk, whereas Cr, Cu, Zn, Ni, and Pb had low ecological risk. The potential ecological risk index (RI) of the heavy metals in sediments of the Liangtan River was 174.9, indicating moderate ecological risk. The transfer factor trend of metals for aquatic plants showed that Cd and Ni had the most and least accumulation, respectively. For Cu, Cd, Mg, Pb, and Cr, a significant positive correlation of the metal concentrations was observed between sediments and soils, but no correlations (excluding Cr) were detected between sediments and aquatic plants. Our study indicated that anthropogenic input may be the primary source of metal contamination in the Liangtan River, and that Zn and Cd pollution in the Liangtan River should be further explored.
Show more [+] Less [-]Amelioration of iron mine soils with biosolids: Effects on plant tissue metal content and earthworms
2016
Cele, Emmanuel Nkosinathi | Maboeta, Mark
The achievement of environmentally sound and economically feasible disposal strategies for biosolids is a major issue in the wastewater treatment industry around the world, including Swaziland. Currently, an iron ore mine site, which is located within a wildlife sanctuary, is being considered as a suitable place where controlled disposal of biosolids may be practiced. Therefore, this study was conducted to investigate the effects of urban biosolids on iron mine soils with regard to plant metal content and ecotoxicological effects on earthworms. This was done through chemical analysis of plants grown in biosolid-amended mine soil. Earthworm behaviour, reproduction and bioaccumulation tests were also conducted on biosolid-amended mine soil. According to the results obtained, the use of biosolids led to creation of soil conditions that were generally favourable to earthworms. However, plants were found to have accumulated Zn up to 346 mg kg⁻¹ (in shoots) and 462 mg kg⁻¹ (in roots). This was more than double the normal Zn content of plants. It was concluded that while biosolids can be beneficial to mine soils and earthworms, they can also lead to elevated metal content in plant tissues, which might be a concern to plant-dependant wildlife species. Nonetheless, it was not possible to satisfactorily estimate risks to forage quality since animal feeding tests with hyperaccumulator plants have not been reported. Quite possibly, there may be no cause for alarm since the uptake of metals from soil is greater in plants grown in pots in the greenhouse than from the same soil in the field since pot studies fail to mimic field conditions where the soil is heterogeneous and where the root system possesses a complex topology. It was thought that further field trials might assist in arriving at more satisfactory conclusions.
Show more [+] Less [-]Simulation of aromatic polycyclic hydrocarbons remobilization from a river sediment using laboratory experiments supported by passive sampling techniques
2016
Belles, Angel | Mamindy-Pajany, Yannick | Alary, Claire
Resuspension of bedded sediments was simulated under laboratory-controlled conditions in order to assess the amount of polycyclic aromatic hydrocarbons (PAH) remobilized in the dissolved fraction during one short and vigorous mixing. The desorbed amount of PAH was compared to the exchangeable fraction, the total amount of PAH sorbed on the sediment particles, and the dissolved PAH amount contained in the interstitial pore waters in order to evaluate the contribution of each fraction to the total amount of PAH released. To monitor the desorption of PAH and measure low trace level concentrations, passive samplers were used in an experimental open flow through exposure simulator. Results show that for the selected sediment, a substantial fraction of sorbed PAH (69 % of the total amount) is not available for remobilization in a depleted medium. Obtained data pinpoint that over 9 days, only 0.007 % of PAH are desorbed by passive diffusion through a water-sediment interface area of 415 cm² and that an intense resuspension event of 15 min induces desorption of 0.015 % of PAH during the following 9 days. Results also highlight that during resuspension simulation, modifications of the sediment and the water body occurred since partitioning constants of some pollutants between sediment and water have significantly decreased.
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