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Survey of cyanobacterial toxins in Czech water reservoirs—the first observation of neurotoxic saxitoxins 全文
2014
Jančula, Daniel | Straková, Lucie | Sadílek, Jan | Maršálek, Blahoslav | Babica, Pavel
The environmental occurrence and concentrations of cyanobacterial toxins (cyanotoxins) were investigated in the Czech Republic. Concentrations of microcystins (MCs), cylindrospermopsin (CYN) or saxitoxins (STXs) were determined immunochemically by ELISA assays in 30 water samples collected from the surface layers of 19 reservoirs during the summer season of 2010. MCs were detected in 18 reservoirs and 83 % of samples, with median and maximal concentration being 1.5 and 18.6 μg/L, respectively. The high frequency of MC occurrence coincided with prevalence of cyanobacterium Microcystis sp., which was detected in 87 % samples, followed by Dolichospermum (Anabaena) sp. observed in 33 % samples. CYN was detected by ELISA only in one sample at a concentration of 1.2 μg/L. STXs presence was indicated for the first time in Czech water reservoirs when the toxins were found at low concentrations (0.03–0.04 μg/L) in two samples (7 %) collected from two different reservoirs, where STXs co-occurred with MCs and eventually also with CYN. In both STX-positive samples, the phytoplankton community was dominated by Microcystis sp., but Dolichospermum sp. and/or Aphanizomenon sp. were also present as putative producers of STX and/or CYN. Cyanotoxins commonly occurred in Czech water reservoirs, and MCs frequently at concentrations possibly associated with human health risks. MCs were the most prevalent and abundant cyanotoxins, but also other cyanotoxins were detected, though sporadically. Further research and regulatory monitoring of cyanotoxins other than MCs is therefore required.
显示更多 [+] 显示较少 [-]Influence of the organic loading rate on the performance and the granular sludge characteristics of an EGSB reactor used for treating traditional Chinese medicine wastewater 全文
2014
Li, Weiguang | Su, Chengyuan | Liu, Xingzhe | Zhang, Lei
The effects of the organic loading rate (OLR) on the performance and the granular sludge characteristics of an expanded granular sludge bed (EGSB) reactor used for treating real traditional Chinese medicine (TCM) wastewater were investigated. Over 90 % of the COD removal by the EGSB reactor was observed at the OLRs of 4 to 13 kg COD/(m³ day). However, increasing the OLR to 20 kg COD/(m³ day) by reducing the hydraulic retention time (HRT 6 h) reduced the COD removal efficiency to 78 %. The volatile fatty acid (VFA) concentration was 512.22 mg/L, resulting in an accumulation of VFAs, and propionic acid was the main acidification product, accounting for 66.51 % of the total VFAs. When the OLR increased from 10 to 20 kg COD/(m³ day), the average size of the granule sludge decreased from 469 to 258 μm. There was an obvious reduction in the concentration of Ca²⁺and Mg²⁺in the granular sludge. The visible humic acid-like peak was identified in the three-dimensional excitation-emission matrix (EEM) fluorescence spectra of the soluble microbial products (SMPs). The fatty acid bond, amide II bond, amide III bond, and C–H bond bending were also observed in the Fourier transform infrared (FTIR) spectra of the SMPs. Methanobacterium formicicum, Methanococcus, and Bacteria populations exhibited significant shifts, and these changes were accompanied by an increase in VFA production. The results indicated that a short HRT and high OLR in the EGSB reactor caused the accumulation of polysaccharides, protein, and VFAs, thereby inhibiting the activity of methanogenic bacteria and causing granular sludge corruption.
显示更多 [+] 显示较少 [-]Accumulation of chlorothalonil and its metabolite, 4-hydroxychlorothalonil, in soil after repeated applications and its effects on soil microbial activities under greenhouse conditions 全文
2014
Wu, Xiangwei | Yin, Yuanming | Wang, Shaoyun | Yu, Yunlong
The effect of repeated chlorothalonil applications on its persistence and soil microbial activities were investigated in planted soil under greenhouse conditions. The results revealed that suppressed dissipation of chlorothalonil and the consequent accumulation of chlorothalonil and its toxic metabolite, 4-hydroxychlorothalonil, resulted from four successive applications at rates of 2, 4, and 10 kg a.i./ha. Soil respiration for 7 h (SR7) was slightly affected by chlorothalonil applications at all three levels, whereas soil respiration for 24 h (SR24) at 10 kg a.i./ha was reduced by 17.6–59.1 %, depending upon the frequency. This harmful effect of chlorothalonil on SR24 persisted throughout the experiment although it gradually weakened with time. A persistent inhibitory effect on soil dehydrogenase activity was also observed with repeated applications of chlorothalonil at 10 kg a.i./ha. This study indicated that repeated chlorothalonil applications may lead to the accumulation of chlorothalonil and its metabolite in soil under greenhouse conditions and thereby alter soil microbial activity.
显示更多 [+] 显示较少 [-]Heavy metal concentrations in Mullus barbatus and Pagellus erythrinus in relation to body size, gender, and seasonality 全文
2014
Giannakopoulou, Loukia | Neofitou, Christos
Marine environments have been subjected to an increase in heavy metal pollution. Investigations were conducted in the bioaccumulation of heavy metals for both a benthic (Mullus barbatus) and a benthopelagic fish species (Pagellus erythrinus). The aim of this study was to examine the concentration levels of four metals in the body tissue of two fish species, in Pagasitikos Gulf in Greece, and to determine if metal concentration levels were affected by season, size, and species. Fish samples were collected monthly from September 2009 to August 2010. Chromium (Cr), Copper (Cu), Zinc (Zn), and Cadmium (Cd) concentrations were measured in muscle, gills, vertebral column, and in the “remaining fish sample.” Statistical analysis pinpointed substantial differences in metal concentration levels between some size classes. Significant differences were observed between two fish species’ tissues concerning Cu, Zn, and Cd concentrations. Cu and Zn concentrations varied amongst red mullet tissues as did Zn and Cd concentrations in common pandora. Ample variations were found seasonally in metal concentration levels; however, nonsignificant statistical differences were found among sexes.
显示更多 [+] 显示较少 [-]Systematic screening of common wastewater-marking pharmaceuticals in urban aquatic environments: implications for environmental risk control 全文
2014
Zhou, Haidong | Zhang, Qingjun | Wang, Xuelian | Zhang, Qianqian | Ma, Lixin | Zhan, Yong
In this report, we refer to pharmaceuticals that are widespread in the urban aquatic environment and that mainly originate from wastewater treatment plants or non-point source sewage as “wastewater-marking pharmaceuticals” (WWMPs). To some extent, they reflect the condition or trend of water contamination and also contribute to aquatic environmental risk assessment. The method reported here for screening typical WWMPs was proposed based on academic concerns about them and their concentrations present in the urban aquatic environment, as well as their properties of accumulation, persistence, eco-toxicity and related environmental risks caused by them. The screening system consisted of an initial screening system and a further screening system. In the former, pharmaceuticals were categorised into different evaluation levels, and in the latter, each pharmaceutical was given a normalised final evaluation score, which was the sum of every score for its properties of accumulation, persistence, eco-toxicity and environmental risk in the aquatic environment. The system was applied to 126 pharmaceuticals frequently detected in the aquatic environment. In the initial screening procedure, five pharmaceuticals were classified into the “high” category, 16 pharmaceuticals into the “medium” category, 15 pharmaceuticals into the “low” category and 90 pharmaceuticals into the “very low” category. Subsequently, further screening were conducted on 36 pharmaceuticals considered as being of “high”, “medium” and “low” categories in the former system. We identified 7 pharmaceuticals with final evaluation scores of 1–10, 10 pharmaceuticals with scores of 11–15, 15 pharmaceuticals with scores from 16 to 20 and 4 pharmaceuticals with scores above 21. The results showed that this screening system could contribute to the effective selection of target WWMPs, which would be important for spatial-temporal dynamics, transference and pollution control of pharmaceuticals in the urban aquatic environment. However, there remains a number of pharmaceutical parameters with measured data gaps, such as organic carbon adsorption coefficients and bioconcentration factors, which, if filled, would improve the accuracy of the screening system.
显示更多 [+] 显示较少 [-]Influence of spontaneous vegetation in stormwater infiltration system clogging 全文
2014
Gonzalez-Merchan, Carolina | Barraud, Sylvie | Bedell, Jean-Philippe
The paper presents the role of spontaneous vegetation on the hydraulic performance of an infiltration basin. The objective of the research was more particularly to study this role of different types of spontaneous vegetation found in situ in an infiltration basin near Lyon. The saturated hydraulic conductivity of three areas covered by Phalaris arundinacea, Polygonum mite, Rumex crispus and similar non-vegetated zones was compared. Eight field campaigns were carried out from July 2010 to May 2011 in order to compare the performance of each type of vegetation and its evolution over time. The results suggest a positive impact of vegetation on hydraulic performance in particular in summer during the growth of the plants. The hydraulic conductivity in this period was twice to four times higher than in bare areas or in vegetated zones during the plant rest periods. Some species were also found more appropriate to limit clogging (Phalaris arundinacea) likely due to its specific structure and growth process.
显示更多 [+] 显示较少 [-]Radioactive isotopes in atmospheric aerosols over Russia and the Sea of Japan following nuclear accident at Fukushima Nr. 1 Daiichi Nuclear Power Station in March 2011 全文
2014
Neroda, Andrey S. | Mishukov, Vasily F. | Goryachev, Vladimir A. | Simonenkov, Denis V. | Goncharova, Anna A.
Artificial radionuclides, such as iodine-131 (¹³¹I), cesium-134 (¹³⁴Cs), and cesium-137 (¹³⁷Cs), as well as natural isotopes of beryllium-7 (⁷Be) and potassium-40 (⁴⁰K) have been registered in atmospheric aerosols over Vladivostok selected from 11 March to 17 June 2011. Additionally,¹³⁴Cs and¹³⁷Cs were detected in atmospheric aerosols over Tomsk selected from 16 March to 17 June 2011. Artificial radionuclides were also discovered in atmospheric wet depositions sampled in Vladivostok from 3 to 17 May 2011. Moreover, these radionuclides have been registered in atmospheric aerosols over the sea surface of the Sea of Japan selected from 3 to 31 May 2011 during an expedition of the “Nadezhda” sailing ship. From 18 March to 15 April, an increase in concentrations of atmospheric aerosols over Vladivostok from 108.8 to 321.5 μg/m³has been registered. It was accompanied by increased activity concentrations of¹³⁴Cs,¹³⁷Cs, and the¹³¹I. During the period from 18 March to 15 April, activity concentrations of¹³⁷Cs and¹³⁴Cs in atmospheric aerosols increased 100 times compared with the minimum detectable concentration (MDC) level and peaked in the weekly sample gathered from 8 to 15 April (145.0 and 105.3 μBq/m³, respectively). Variability of concentrations of natural isotopes of⁷Be and⁴⁰K was not greater than 1 order of magnitude throughout the sampling period. Maximal values of¹³⁷Cs and¹³⁴Cs concentrations (1,281.5 ± 141 and 384.4 ± 42.3 μBq/m³, respectively) in Tomsk were reached in samples taken from 1 to 2 April. For the atmospheric aerosol samples from the Sea of Japan, the largest concentration of¹³¹I (392.3 ± 215.7 μBq/m³) was detected from 13 to 19 May, while all other samples had much lower concentration values. Synoptic analysis of back trajectories movement of air masses showed that the radioactive cloud came to Vladivostok from the regions of Siberia and northeastern part of China. Synoptic analysis for Tomsk showed that during the period of maximal activity concentrations (1–9 April), air masses were arriving from the European part of Russia and north of Kazakhstan.
显示更多 [+] 显示较少 [-]Performance of the Arctic calanoid copepods Calanus glacialis and C. hyperboreus under elevated pCO2 and temperatures 全文
2014
Hildebrandt, Nicole | Niehoff, Barbara | Sartoris, Franz-Josef
Performance of the Arctic calanoid copepods Calanus glacialis and C. hyperboreus under elevated pCO2 and temperatures 全文
2014
Hildebrandt, Nicole | Niehoff, Barbara | Sartoris, Franz-Josef
The sensitivity of copepods to ocean acidification (OA) and warming may increase with time, however, studies >10 days and on synergistic effects are rare. We therefore incubated late copepodites and females of two dominant Arctic species, Calanus glacialis and Calanus hyperboreus, at 0 °C at 390 and 3000 µatm pCO2 for several months in fall/winter 2010. Respiration rates, body mass and mortality in both species and life stages did not change with pCO2. To detect synergistic effects, in 2011 C. hyperboreus females were kept at different pCO2 and temperatures (0, 5, 10 °C). Incubation at 10 °C induced sublethal stress, which might have overruled effects of pCO2. At 5 °C and 3000 µatm, body carbon was significantly lowest indicating a synergistic effect. The copepods, thus, can tolerate pCO2 predicted for a future ocean, but in combination with increasing temperatures they could be sensitive to OA.
显示更多 [+] 显示较少 [-]Long-term effects of elevated CO2 and temperature on the Arctic calanoid copepods Calanus glacialis and C. hyperboreus 全文
2014
Hildebrandt, Nicole | Niehoff, Barbara | Sartoris, Franz Josef
The sensitivity of copepods to ocean acidification (OA) and warming may increase with time, however, studies >10 days and on synergistic effects are rare. We therefore incubated late copepodites and females of two dominant Arctic species, Calanus glacialis and C. hyperboreus, at 0 °C at 390 and 3000 µatm pCO2 for several months in fall/winter 2010. Respiration rates, body mass and mortality in both species and life stages did not change with pCO2. To detect synergistic effects, in 2011 C. hyperboreus females were kept at different pCO2 and temperatures (0, 5, 10 °C). Incubation at 10 °C induced sublethal stress, which might have overruled effects of pCO2. At 5 °C and 3000 µatm, body carbon was significantly lowest indicating a synergistic effect. The copepods, thus, can tolerate pCO2 predicted for a future ocean, but in combination with increasing temperatures they could be sensitive to OA.
显示更多 [+] 显示较少 [-]Long-term effects of elevated CO2 and temperature on the Arctic calanoid copepods Calanus glacialis and C. hyperboreus 全文
2014
Hildebrandt, Nicole | Niehoff, Barbara | Sartoris, Franz Josef
The sensitivity of copepods to ocean acidification (OA) and warming may increase with time, however, studies >10days and on synergistic effects are rare. We therefore incubated late copepodites and females of two dominant Arctic species, Calanus glacialis and Calanushyperboreus, at 0°C at 390 and 3000μatm pCO2 for several months in fall/winter 2010. Respiration rates, body mass and mortality in both species and life stages did not change with pCO2. To detect synergistic effects, in 2011 C. hyperboreus females were kept at different pCO2 and temperatures (0, 5, 10°C). Incubation at 10°C induced sublethal stress, which might have overruled effects of pCO2. At 5°C and 3000μatm, body carbon was significantly lowest indicating a synergistic effect. The copepods, thus, can tolerate pCO2 predicted for a future ocean, but in combination with increasing temperatures they could be sensitive to OA.
显示更多 [+] 显示较少 [-]Biomarkers in the Siak River System, E. Sumatra, Indonesia 全文
2014
Liebezeit, Gerd | Wöstmann, Ralf | Ziehe, Daniel
A total of 33 plant species and 122 surface sediments were obtained from March 2004 to November 2008 in the Siak River system including its major tributaries and coastal areas. Grain size distribution shows the sediments to be sands to silt with a general trend of coarser sediments in the upper reaches and fi ner ones in the estuary. The expected linear relationship between the content of organic carbon and the mud fraction of the sediments (<63 µm) is distorted by input of (a) clay-sized, organic-poor material from river bank erosion and (b) input of coarse plant detritus. All samples were analysed for n-alkanes and steroids. For all plant samples and a limited number of sediment samples, fatty acids were also determined. The data indicate a variety of organic carbon sources, the dominant one being river bank vegetation. Urban and industrial discharges, peat erosion and atmospheric deposition of black carbon and biomarkers might also play a role in controlling the lipid composition of the sedimentary organic carbon pool.
显示更多 [+] 显示较少 [-]Effective management for acidic pollution in the canal network of the Mekong Delta of Vietnam: a modeling approach 全文
2014
Phong, N.D. | Hoanh, Chu Thai | To Phuc Tuong | Malano, H.M.M.
Effective management for acidic pollution in the canal network of the Mekong Delta of Vietnam: a modeling approach 全文
2014
Phong, N.D. | Hoanh, Chu Thai | To Phuc Tuong | Malano, H.M.M.
Acidic pollution can cause severe environmental consequences annually in coastal areas overlain with acid sulfate soils (ASS). A water quality model was used as an analytical tool for exploring the effects of water management options and other interventions on acidic pollution and salinity in Bac Lieu, a coastal province of the Mekong Delta. Fifty eight percent of the provincial area is covered by ASS, and more than three-fourths (approximately 175,000 ha) are used for brackish-water shrimp culture. Simulations of acid water propagation in the canal network indicate that the combination of opening the two main sluices along the East Sea of the study area at high tide for one day every week in May and June and widening the canals that connect these sluices to the West Sea allows for adequate saline water intake and minimizes the acidic pollution in the study area. On the other hand, canal dredging in the freshwater ASS area should be done properly as it can create severe acidic pollution.
显示更多 [+] 显示较少 [-]Effective management for acidic pollution in the canal network of the Mekong Delta of Vietnam: a modeling approach 全文
2014
Phong, N. D. | Hoanh, Chu Thai | Tuong, T. P. | Malano, H.
Acidic pollution can cause severe environmental consequences annually in coastal areas overlain with acid sulfate soils (ASS). A water quality model was used as an analytical tool for exploring the effects of water management options and other interventions on acidic pollution and salinity in Bac Lieu, a coastal province of the Mekong Delta. Fifty eight percent of the provincial area is covered by ASS, and more than three-fourths (approximately 175,000 ha) are used for brackish-water shrimp culture. Simulations of acid water propagation in the canal network indicate that the combination of opening the two main sluices along the East Sea of the study area at high tide for one day every week in May and June and widening the canals that connect these sluices to the West Sea allows for adequate saline water intake and minimizes the acidic pollution in the study area. On the other hand, canal dredging in the freshwater ASS area should be done properly as it can create severe acidic pollution.
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