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Giant panda foraging and movement patterns in response to bamboo shoot growth Полный текст
2018
Zhang, Mingchun | Zhang, Zhizhong | Li, Zhong | Hong, Mingsheng | Zhou, Xiaoping | Zhou, Shiqiang | Zhang, Jindong | Hull, Vanessa | Huang, Jinyan | Zhang, Hemin
Diet plays a pivotal role in dictating behavioral patterns of herbivorous animals, particularly specialist species. The giant panda (Ailuropoda melanoleuca) is well-known as a bamboo specialist. In the present study, the response of giant pandas to spatiotemporal variation of bamboo shoots was explored using field surveys and GPS collar tracking. Results show the dynamics in panda-bamboo space-time relationships that have not been previously articulated. For instance, we found a higher bamboo stump height of foraged bamboo with increasing elevation, places where pandas foraged later in spring when bamboo shoots become more fibrous and woody. The time required for shoots to reach optimum height for foraging was significantly delayed as elevation increased, a pattern which corresponded with panda elevational migration patterns beginning from the lower elevational end of Fargesia robusta distribution and gradually shifting upward until the end of the shooting season. These results indicate that giant pandas can respond to spatiotemporal variation of bamboo resources, such as available shoots. Anthropogenic interference of low-elevation F. robusta habitat should be mitigated, and conservation attention and increased monitoring should be given to F. robusta areas at the low- and mid-elevation ranges, particularly in the spring shooting season.
Показать больше [+] Меньше [-]Toxicological assessment of hospital wastewater in different treatment processes Полный текст
2018
Hamjinda, NuttaSangnarin | Chiemchaisri, Wilai | Watanabe, Tōru | Honda, Ryo | Chiemchaisri, Chart
This study surveyed the hospital wastewater characters focusing on antibiotic contamination in seven hospitals in Bangkok. It detected 19 antibiotics of which the high-frequent detection were quinolones such as ofloxacin + levofloxacin, norfloxacin, ciprofloxacin including sulfamethoxazole. Norfloxacin and ciprofloxacin appeared the highest concentrations of 12.11 and 9.60 μg/L, respectively. Most antibiotic concentrations in the wastewaters of the studied hospitals gave a good correlation (r ² = 0.77–0.99) to the amount of usage. In this study, batch acute toxicity tests were performed to assess the toxicity of hospital wastewater on mixed liquor, freshwater algae (Chlorella vulgaris and Scenedesmus quadricauda), and microcrustacean (Moina macrocopa). The hospital wastewaters could inhibit the mixed liquor growth and gave similar toxic levels among test species: algae and microcrustacean (9.81–13.63 and 2.62–3.09 TU, respectively). The conventional activated sludge (CAS) and rotating biological contactor (RBC) could remove fluoroquinolones and tetracycline via biomass adsorption. After treatment, most of treatment could reduce the toxicity. Nevertheless, the effluent gave slight toxicity on some test species which might be caused from chlorination and a common toxicant (NH₃-N).
Показать больше [+] Меньше [-]Occurrence and toxicological assessment of polycyclic aromatic hydrocarbons (PAHs) in marine sediments under mussel farming influence Полный текст
2018
Pérez-Fernández, Begoña | Viñas, Lucía | Bargiela, Jesica
The use of marine resources for mussel culture has become increasingly important, particularly on the European Atlantic coast and notably in the Galician Rías in the northwest of Spain. Despite its importance, there is a lack of research and analysis in this area and of the potential problems that it could cause to the environment. This paper details the findings of a study that aimed to find the probable environmental impact of mussel culture activities and to evaluate the polycyclic aromatic hydrocarbon (PAH) content derived from this activity. The Ría de Arousa, where you can find over 70% of all installed rafts in Galicia, was selected for the present study, and nearly 40 marine sediment samples were collected there. The sediments were extracted by ASE (accelerated solvent extraction) procedure, and the quantification of PAHs was performed using gas chromatography coupled to mass spectrometry (GC-MS), with the aid of deuterated PAH internal standards. The total concentration of parental PAHs ranged from 11.66 to 30,272-ng g⁻¹ dry weight (d.w.), with a mean value of 3907-ng g⁻¹ d.w.; the concentration of alkyl PAHs varied from 3.72 to 1187-ng g⁻¹ d.w., with a mean value of 205.1-ng g⁻¹ d.w. Compositional patterns, principal component analysis (PCA) and hieratical cluster association (HCA) yielded a sediment classification where the mussel raft impact is pointed out. PAH ratios indicated a predominance of combustion sources, except in two samples, located in small harbors. Only one station showed total potential carcinogenic PAH values in the range that would frequently cause negative biological effects, and the toxic equivalent concentrations based on BaP equivalents identified another ten positions where biological effects would occur occasionally.
Показать больше [+] Меньше [-]Synthesis of a molecularly imprinted polymer and its application in selective extraction of fenoprofen from wastewater Полный текст
2018
Mbhele, Zama Emmaculate | Ncube, Somandla | Madikizela, Lawrence Mzukisi
The presence of various classes of pharmaceutical drugs in different environmental compartments has been reported worldwide. In South Africa, the detection of pharmaceuticals especially the non-steroidal anti-inflammatory drugs is recent, and more studies are being done in order to fully understand their fate in the aquatic environment. With considerations for the need of better sample preparation techniques, this study synthesized a molecularly imprinted polymer for the selective extraction of a non-steroidal anti-inflammatory drug, fenoprofen in aqueous environmental samples. Batch adsorption studies showed that adsorption of fenoprofen onto the cavities of the polymer followed a Langmuir isotherm as well as a pseudo second order model implying formation of a monolayer on the surface through chemisorption. The polymer had a maximum adsorption capacity of 38.8 mg g⁻¹ and a Langmuir surface area of 1607 m² g⁻¹. The imprinted polymer was then used as the selective sorbent for solid phase extraction in the analysis of fenoprofen from wastewater followed by chromatographic determination. The analytical method gave a detection limit of 0.64 ng mL⁻¹ and recovery of 99.6%. The concentration of fenoprofen detected in influent and effluent samples from two wastewater treatment plants ranged from 24 to 58 ng mL⁻¹. The ability of the treatment plants to remove fenoprofen during wastewater processing based on the difference in concentrations in influent and effluent samples was found to be 41%. This work has shown that there is a possibility of release of fenoprofen from wastewater treatment plants into surface water sources.
Показать больше [+] Меньше [-]The impact of kraft pulping effluent on egg survival and hatching success in two species of Clupeiformes (Teleostei) Полный текст
2018
Llanos-Rivera, Alejandra | Castro, Leonardo R. | Vásquez, Paulina | Silva, Jeannette | Bay-Schmith, Enrique
The anchoveta (Engraulis ringens) and sardine (Strangomera bentincki) are coastal pelagic species with important spawning areas off the coast of Chile. The discharge of secondary-treated effluents from a kraft pulp plant near one of these spawning areas has raised environmental concerns. Therefore, effluent effects on the development of anchoveta and sardine eggs were assessed by in vitro exposure. Eggs were sampled between 2007 and 2010 off Talcahuano, Chile. Subsequent toxicity tests (96 h duration, 12 °C) were performed using increasing effluent concentrations, a filtered seawater control, and two potassium dichromate concentrations (to verify consistent embryonic sensitivity). Egg mortality and hatching success were evaluated. For anchoveta, mortality (9.9 ± 7.1%) did not significantly differ among groups in five toxicity tests except the final toxicity test that showed significant differences in mortality (5.6% control vs 27.8% in 100% effluent). For sardines, no differences in mortality existed between the effluent dilutions (2.6 ± 3.6%) and control (6.3 ± 3.9%). Notably, anchoveta egg survival and hatching success rates were inconsistent, i.e., the highest rates of hatching failure occurred on the same sampling date with the highest rates of survival for the 100% effluent group (72%). In conclusion, the obtained results indicate that (i) anchoveta egg mortality and hatching failure increase only under 100% effluent exposure, coinciding with decreased egg quality near the end of spawning season and (ii) high effluent dilutions not significantly increase sardine and anchoveta egg mortalities. Nevertheless, the recorded adverse effects to the hatching process should be studied in greater detail, particularly considering interspecific variability and the complexity of reproductive processes, especially during early development.
Показать больше [+] Меньше [-]The variability of Hg concentration and composition of marine phytoplankton Полный текст
2018
Bełdowska, Magdalena | Kobos, Justyna
Mercury is a toxic element. It undergoes biomagnification in the marine trophic chain, which is why it is significant to identify the factors influencing its bioaccumulation on the first level of the trophic chain. At present, the input of heavy metals to the southern Baltic is being reduced. On the other hand, the parameters influencing mercury remobilisation in the environment are a subject to a long-time trend associated with climate changes. Examples include growing number of heavy rain events causing surges or floods, and increased frequency of storm winds leading to increased coastal erosion as well as overall temperature increase. The present studies were carried out in the coastal zone of the Gulf of Gdańsk (southern Baltic) for 18 months at two stations (Chałupy and Osłonino) located in the Puck Lagoon, and for 12 months in Gdynia. Climate changes influence the abundance and species composition of phytoplankton, which in consequence has an effect on Hg accumulation and magnification in the trophic chain, and in the human body as a result. Extreme phenomena such as land erosion or floods resulted in an additional inflow of nutrients, but also toxic substances, into the coastal zone. The bioconcentration factor (BCF) increased almost four times after abrasion of cliff. That was conducive to the growth of microflora, as well as increased Hg accumulation. The highest bioconcentration of Hg in phytoplankton was observed when the Mesodinium rubrum (spring and autumn) and Diatomophyceae (winter) prevailed in biomass. The BCF was then almost tenfold higher than during the rest of the year.
Показать больше [+] Меньше [-]Identifying indicator redundancy of biofilm-dwelling protozoa for bioassessment in marine ecosystems Полный текст
2018
Xu, Guangjian | Al Mamun, Abdullah | Sikder, Mohammad Nurul Azim | Warren, Alan | Xu, Henglong
A multivariate peeling method of data analysis was applied to determine indicator redundancy and for identifying indicator units (IUs) among biofilm-dwelling ciliate communities used for bioassessment of marine water quality. Samples were taken monthly over a 1-year period at four stations in coastal waters of the Yellow Sea: one heavily polluted, one moderately polluted, one intermittently polluted, and one unpolluted. Four IUs (IU1–4) were identified consisting of 22, 13, 14, and 17 species, respectively, out of a total of 144 species. The IUs showed significant correlation with temporal and spatial variations in environmental variables. The redundancy levels of IUs were interchangeable in time and space. However, IU1 and IU2 generally dominated the communities in moderately and intermittently polluted areas during cool (e.g., early spring, late autumn, and winter) and warm (late spring and early autumn) seasons; IU3 dominated in warm seasons (e.g., late spring to autumn) in the heavily polluted area; and IU4 mainly dominated the samples in the unpolluted and moderately polluted areas during the late summer and early autumn. Furthermore, different trophic-functional groupings were represented within the four IUs and these were generally associated with water quality status. These findings suggest that there is high indicator redundancy in marine biofilm-dwelling ciliate communities subjected to different levels of water quality.
Показать больше [+] Меньше [-]Study on the removal effect and influencing factors of nitrobenzene reduction by iron carbonate precipitates Полный текст
2018
Wei, Tao | Hong, Mei | Liu, Lu
To investigate the activity of iron carbonate precipitates produced by long-term operation of Fe⁰ permeable reactive barriers, three kinds of precipitates, namely Fe₆(OH)₁₂CO₃, Fe₂(OH)₂CO₃, and FeCO₃, were prepared to reduce the pollutant nitrobenzene. We studied the reduction effects of these iron carbonate precipitates on nitrobenzene by considering three factors, namely the initial nitrobenzene concentration, initial pH, and precipitate dosage, and established the kinetic degradation using pseudo-first-order kinetics model. The results showed that all three precipitates can reduce nitrobenzene, and the order of reducing capability is Fe₆(OH)₁₂CO₃ > Fe₂(OH)₂CO₃ > FeCO₃; moreover, the removal efficiency values of nitrobenzene are 68.08, 53.00, and 50.29%. A high initial nitrobenzene concentration and high pH value are beneficial to nitrobenzene reduction, and removal efficiency was increased when pH was increased from 4 to 9. In addition, the increased precipitate addition in the Fe₆(OH)₁₂CO₃ and Fe₂(OH)₂CO₃ systems increased removal efficiency. Furthermore, the dosage did not significantly influence the removal rate in the FeCO₃ system. Fe₆(OH)₁₂CO₃ and Fe₂(OH)₂CO₃ mainly relied on the precipitate itself with the structural Fe(II) to reduce nitrobenzene, and FeCO₃ mainly relied on the dissolved Fe²⁺. The reaction of all three precipitates in reducing nitrobenzene followed the first-order reaction kinetics.
Показать больше [+] Меньше [-]Novel magnetic graphene oxide functionalized cyanopropyl nanocomposite as an adsorbent for the removal of Pb(II) ions from aqueous media: equilibrium and kinetic studies Полный текст
2018
Gabris, Mohammad Ali | Jume, Binta Hadi | Rezaali, Mostafa | Shahabuddin, Syed | Nodeh, Hamid Rashidi | Saidur, Rahman
This work presents the synthesis of the novel silica-cyanopropyl functionalized magnetic graphene oxide (MGO/SiO₂-CN) hybrid nanomaterial derived by sol–gel method as a cheap efficient magnetic sorbent for the removal of extremely hazardous lead ions from aqueous media. The integration of the magnetic property, the carbon substrate, and the nitrile (–C ≡ N) containing organic grafted silica matrix promoted the adsorption capability against lead ions along with its simple synthesis recovery and low cost. The prepared nanocomposite was comprehensively characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Adsorption of lead was found to be pH dependent because of the charged nature of both analyte and adsorbent surface. Adsorption experiments were conducted under the optimum conditions, and the obtained experimental data from atomic absorption spectroscopy were analyzed using the popular isothermal models namely Langmuir, Freundlich, and Dubinin–Radushkevich isotherms as well as kinetically studied and evaluated for adsorption standard free energy (E). The experimental results have demonstrated the enhanced adsorption capability of the proposed sorbent nanocomposite for lead ion removal with the maximum adsorption capacity of 111.11 mg/g at pH 5.0. The proposed mechanism of lead adsorption was mainly attributed to the complexation of lead positive ions with the grafted –C ≡ N bond. The synergistic effect of the combination of three components (i.e., the magnetic graphene oxide matrix, the triple bond containing organic moiety, and the inorganic porous silica framework) excelled the adsorption capability and proved to be a good candidate as adsorbent for the removal of lead ions.
Показать больше [+] Меньше [-]Annual variability of heavy metal content in Svalbard reindeer faeces as a result of dietary preferences Полный текст
2018
Węgrzyn, Michał Hubert | Wietrzyk, Paulina | Lehmann-Konera, Sara | Chmiel, Stanisław | Cykowska-Marzencka, Beata | Polkowska, Żaneta
During both winter and summer, Svalbard reindeer selectively feed on different types of vegetation that are not only a source of nutritional value, but also a place of heavy metal accumulation. In the present study, the content of cadmium, chromium, copper, iron, lead, nickel, manganese, and zinc in reindeer excrement was measured. The main aims were to determine the seasonal content of several heavy metals in Svalbard reindeer faeces, and to compare their values in terms of dietary preferences during the year. Summer and winter reindeer excrement was gathered along a designated linear transect running through Bolterdalen and the vegetation described on 1 m² plots. All of the analysed heavy metals were detected in the reindeer faeces and this fact seems to be connected with the incomplete content of these elements in an animal’s tissue after forage digestion. Analysis showed differences between summer and winter excrement in terms of concentrations of cadmium, chromium, iron, and nickel, but no differences were found for the other four elements analysed (manganese, lead, zinc, and copper). However, concentrations of heavy metals in faeces are rather low in comparison with both the levels in the vegetation that may be grazed by reindeer and in reindeer tissue.
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