首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Hormonal responses of broiler chickens exposed to crude petroleum flame and fumes at varying distances over a period of 16 h daily were evaluated for 56 days in a poultry house. The burning of crude petroleum was simulated in a designed burner. The measured distances were 4, 8, or 12 m from the flame point. The experimental design was a two-factor factorial in a completely randomized design (CRD) with factor A as distance from the crude petroleum flame and factor B was the age of birds in weeks. One hundred and eighty Anak day-old broiler chickens were divided into four groups of 45 birds each, replicated thrice at 15 birds per replicate. Control birds were located in a separate poultry building without the flame treatment. Gaseous emissions from the burning crude oil were monitored. Proprietary broiler starter and finisher diets were fed ad libitum. Blood samples were taken at the fourth and eighth week for hormone radioimmunoassay from each treatment. The hormones assayed were growth hormone (GH), thyroxine (T4,), and adrenaline. Results indicated that treatments did not significantly alter hormonal levels. The age of birds significantly affected the levels of all three hormones measured.  相似文献   

2.
Hematological responses of broiler chicken exposed to simulated crude petroleum emissions at varying distances over a period of 16 h daily were evaluated for 56 days in a poultry house. The burning of crude petroleum was simulated with a specially designed burner. The measured distances were 4, 8, or 12 m from the flame point. Control birds were located in a separate poultry building without the flame treatment. Gaseous emissions from the burning crude oil were monitored. Proprietory broiler starter and finisher diets were fed ad libitum. Blood samples were taken at the fourth and eighth weeks for hematological assay from each treatment. The hematological parameters assayed were hemoglobin (Hb), packed cell volume (PCV), white blood cells (WBC), neutrophils, and lymphocytes. Results indicated that the treatment did not significantly affect the Hb, PCV, and WBC constituents. Neutrophils significantly decreased while lymphocytes increased. The age of birds significantly increased Hb, PCV, and WBC levels in the blood.  相似文献   

3.
The isotopic ratios of sulfur and carbon in the tissues of infanal organisms collected from a natural petroleum seep in the Santa Barbara Channel, California, USA were examined to see if petroleum is utilized by the benthic community. Sulfur isotope data were consistent with a pathway of petroleum energy from sulfate reducers → H2S → Beggiatoa sp. → nematodes and other infauna. The carbon of infaunal organisms was isotopically lighter at the seep than at a comparison station; the mean δ13C for 12 species was-1.32‰ towards the petroleum δ13C value. The shifts were largest in two species of deep-feeding maldanid polychaetes. The tissues of one of the species, Praxillella affinis pacifica, were also analyzed for 14C content and δ34S, and the biomass produced by the populations over 26 mo was estimated. The results of these analyses allowed us to estimate that for the seep population: (1) there was 15.6% more fossil carbon, (2) chemoautotrophic bacteria contributed 13.6% more carbon, and (3) 19% more carbon was produced by the population over 26 mo. In spite of the possible sources of error, these values are in reasonable agreement. In general, these data infer that, although petroleum utilization by the benthic food web proceeds both directly through heterotrophs and indirectly through chemoautotrophs, the two pathways are tightly coupled. A carbon budget for P. affinis pacifica was constructed with three assumed sources: chemoautotrophic biomass, petroleum carbon utilized heterotrophically, and nonexotic carbon utilized heterotrophically. Calculations based on this budget indicate that the food web is fueled to a greater extent by the isotopically lighter gases than by the liquid oil.  相似文献   

4.
Swine slurry is a source of atmospheric pollutants. Emissions of basic and acidic compounds from slurry are largely dependent on the surface pH. In a storage system, the pH at the surface layers changes over time due to the volatilisation of ammonia (NH3), carbon dioxide (CO2) and acetic acid (HAc). In this article, a comprehensive gas emission–pH (GE–pH) coupled model is proposed to describe the simultaneous release of acidic and basic gaseous pollutants from swine slurry. The model was applied to describe the release of NH3, CO2, HAc and hydrogen sulphide (H2S) from standard slurries stored in animal houses, outside storage tanks and lagoons. The modelled results agreed well with values reported in the literature and could be reasonably interpreted. The key parameters affecting the release of gases were: initial pH, initial concentration of total ammonium nitrogen and inorganic carbon, slurry temperature and air velocity. This study suggests that future modelling studies on gas emissions from animal slurry should consider the concentration of inorganic carbon and the frequency in which the slurry surface is mixed or altered, because they affect the surface pH and the release of gaseous pollutants from slurry.  相似文献   

5.
Following large crude oil spills, oil from feathers of brooding birds and oiled nesting material can transfer to eggs, resulting in reduced embryonic viability for heavily oiled eggs. Eggs may also be subjected to trace or light oiling, but functional teratogenic effects from sublethal crude oil exposure have not been examined. We assessed whether sublethal application of weathered Deepwater Horizon crude oil to the eggshell surface alters heart rate and metabolic rate in Zebra Finch (Taeniopygia guttata) embryos. We first determined sublethal applications with a dosing experiment. Embryo viability for eggs exposed to 5 μL or more of crude oil decreased significantly. We conducted a second experiment to measure heart rate and metabolic rate (CO2 production) 5 and 9 d after 1 sublethal application of crude oil to eggshells on day 3 of incubation. One application of 1.0 or 2.5 µL of crude oil reduced embryonic heart rate and metabolic rate on day 12 of incubation. Using unfertilized eggs, we measured the transfer of polycyclic aromatic hydrocarbons (PAHs) from the eggshell surface to egg contents 9 d after a single application of sublethal crude oil. Our results suggest avian eggs externally exposed to small amounts of crude oil may exhibit protracted embryonic development and impaired postnatal cardiac performance.  相似文献   

6.
The oxidation of soil organic matter (SOM) and total petroleum hydrocarbon were investigated in two soils at eight different hydrogen peroxide (H2O2) concentrations to determine the optimal H2O2 dosage for the efficient remediation of soils contaminated by crude oil with minimal SOM removal. In our study, H2O2 concentrations up to 1100 mM increased the SOM destruction up to 10%–15% in the two soils while no improvement of the crude oil removal efficiencies was observed. The results indicate that the destruction of SOM significantly limits the oxidation of crude oil because SOM might consume H2O2 more effectively than crude oil at H2O2 concentrations above 1100 mM. In addition, H2O2 concentrations higher than 1100 mM were not expected for both soils because of the extremely rapid H2O2 decomposition, and low H2O2 utilization, of both soils.  相似文献   

7.
Radon (222Rn) and carbon dioxide were monitored simultaneously in soil air under a cool-temperate deciduous stand on the campus of Hokkaido University, Sapporo, Japan. Both 222Rn and CO2 concentrations in soil air varied with atmospheric (soil) temperature in three seasons, except for winter when the temperature in soil air remained constant at 2–3°C at depth of 80 cm. In winter, the gaseous components were influenced by low-pressure region passing through the observation site when the ground surface was covered with snow of ~1 m thickness. Carbon isotopic analyses of CO2 suggested that CO2 in soil air may result from mixing of atmospheric air and soil components of different origins, i.e. CO2 from contemporary soil organic matter and old carbon from deeper source, to varying degrees, depending on seasonal meteorological and thus biological conditions.  相似文献   

8.
Contrasting conditions at-sea are likely to affect the foraging behaviour of seabirds. However, the effect of season on the dive parameters of penguins is poorly known. We report here on an extensive study of the diving behaviour of king penguins (Aptenodytes patagonicus) over the bird's complete annual cycle at the Crozet Islands. Time-depth recorders were used to record dive duration, bottom duration, post-dive interval, ascent rate and descent rate in breeding adults during different seasons in 1995 and 1996. Seasons included summer (n=6, incubation; n=6, chick brooding), autumn and winter (n=5 and n=3, respectively, chick at the crèche stage), and spring (n=4, birds at the post-moult stage). In all seasons dive duration increased with dive depth, but, for a given depth, dives were longer in winter (6.8 min when averaged over the 100-210 m depth layer) than in spring (4.6 min) and summer (4.4 min). The time spent at the bottom of the dives, which probably represents a substantial part of the feeding time, was much longer in winter (2.5 min per dive for dives over the 100-210 m layer) than during other seasons (1.0-1.4 min), i.e. there was a 2.5-fold augmentation for similar diving depths. Ascent and descent rates increased with increasing dive depth, but no difference in the relationships between rates of ascent and descent and dive depth was found among seasons. Furthermore, for all dive depths, ascent and descent rates were independent of the bottom duration. In all seasons post-dive intervals increased with dive duration and with dive depth, but they were longer in spring (2.3 min for dives over the 100-210 m layer) and summer than in autumn and winter (1.6-1.8 min). The diving efficiency decreased with increasing dive depth and was higher in autumn and winter (0.22-0.29) than in summer and spring (0.15-0.18). The large increase in bottom and dive duration from spring to winter is in agreement with the seasonal drop in prey density, with penguins spending more time searching for prey. In contrast, the consistency of the vertical velocity during contrasting conditions at-sea suggests that the transit time to depth is an important component of the foraging behaviour (scanning of the water column) that is independent of the prey availability. The time budget of the penguins during diving in a fluctuating environment appears to vary primarily during the bottom phase of the dives, with bottom duration increasing with diminishing prey supplies, while post-dive intervals shorten in the same time.  相似文献   

9.
The embryonic and larval stages of the quahog clam Mercenaria sp. were exposed to the water-soluble fractions (WSFs) of 6 oils and the effects on survival and growth rate of the various stages were noted. Kuwait crude oil was the least toxic on initial exposure to both stages, having LC50 values in excess of 10 ppm after continuous exposure to the WSF for up to 6 days. However, at 10 days, Kuwait was slightly more toxic than southern Louisiana crude oil, with both oils having LC50 values near 2 ppm. Florida Jay crude oil was much more toxic, with an LC50 of less than 1 ppm at 48 h and less than 0.2 ppm at 10 days. Two refined oils, No. 2 fuel oil and Bunker C, had LC50 values of 1 to 2 ppm after 48 h, while used crankcase motor oil, the most toxic oil tested, had LC50 values of 0.10 ppm or less at all exposure times. Larvae surviving exposure to water-soluble fractions of the various oils often grew at slower rates than the controls.  相似文献   

10.
溢油污染导致的原油和燃料油入海,会对海洋生物的生长发育过程产生影响。为研究溢油污染对海洋虾类的毒性效应,以斑节对虾(Penaeus monodon)为研究对象,比较了不同浓度0#柴油和南海流花原油(LH原油)乳化液对斑节对虾不同发育阶段幼体的急性毒性效应。结果表明,3.59 mg·L~(-1)0#柴油和0.77 mg·L~(-1)LH原油乳化液可以显著降低斑节对虾无节幼体变态率(P0.05),且对无节幼体变态具有延迟效应。较之0#柴油,LH原油乳化液对斑节对虾无节幼体发育的影响更为明显。0#柴油对斑节对虾无节幼体、蚤状幼体、糠虾和仔虾的48或96小时半致死浓度(48 h/96 h-LC50)分别为0.55 mg·L~(-1)、0.42 mg·L~(-1)、0.95 mg·L~(-1)和1.09 mg·L~(-1),其对应的安全浓度分别为0.05 mg·L~(-1)、0.04 mg·L~(-1)、0.10 mg·L~(-1)和0.11 mg·L~(-1);LH原油对上述幼体的48 h/96 h-LC50则依次为0.62 mg·L~(-1)、0.51 mg·L~(-1)、1.05 mg·L~(-1)和1.42 mg·L~(-1),对应的安全浓度分别为0.06 mg·L~(-1)、0.05mg·L~(-1)、0.11 mg·L~(-1)和0.14 mg·L~(-1)。斑节对虾不同发育阶段幼体对0#柴油和LH原油的耐受力依次为:仔虾糠虾无节幼体蚤状幼体,0#柴油和LH原油乳化液对斑节对虾的毒性大小为0#柴油LH原油。上述结果为深入研究石油类污染对海洋生物的毒性效应提供了基础数据和理论依据。  相似文献   

11.
The photocatalytic degradation of diazinon was studied over TiO2 catalysts. The kinetics obtained demonstrated that powder titania (t1/2 = 9.7 min) was more efficient compared to pure titania thin film catalysts (t1/2 = 29.4 min). Mineralization of organic carbon to CO2 after 360 min of irradiation was found to be 75% while heteroatoms (P, S, N) were mineralized into phosphate, sulfate and nitrate ions, respectively. A microtox test was performed to evaluate the toxicity of solutions treated by catalysts. Illumination of diazinon in the presence of TiO2 gave rise to several intermediates that have been identified by means of solid phase extraction and gas chromatography-mass spectrometry, while a simple degradation pathway is proposed.  相似文献   

12.
The cytochrome P450, identified by the characteristic 450 nm spectral peak of its carbon monoxide complex, was detected in the hepatopancreatic microsomes ofMytilus galloprovincialis, collected from Ponteau (Bay of Fos, France) in 1982 and 1983. When mussels were exposed to a variety of petroleum hydrocarbons, the cytochrome P450 content increased. It is shown that aromatic hydrocarbons are more effective than alkanes in inducing a high level of cytochrome P450. The possible use of this haemoprotein in hydrocarbon pollutant detection is discussed.  相似文献   

13.
Antibiotics are newly emerging organic pollutants in manure, soil, vegetables and water. Animal manure application might be leading to the accumulation of antibiotics in the farmland. However, the effect of sulphamethazine (SMZ) on the soil microbial community was scarcely investigated. This study was aimed to evaluate the impact of SMZ on poultry manure, on the structure and function of microbial community, carbon mineralisation, and changes in nitrogen forms in soil via an incubation experiment lasting 56?d. The treatments consisted of poultry manure at 1% wt (PM), PM containing 20?mg?kg?1 SMZ (PM?+?20SMZ) and PM containing 100?mg?kg?1 SMZ (PM?+?100SMZ), along with the untreated soil (control). Solid phase extraction was performed to measure the SMZ concentration in soils using high-pressure liquid chromatography. The cumulative CO2-C was increased in all treated soils over the incubation period compared to the control. The PM?+?100SMZ had the highest increase in cumulative CO2-C from the soil at 56?d of incubation. The treatment of PM?+?20SMZ showed a short-term decrease in nitrification rate in the soils at 1?d by altering the microbial community composition with 17% dissimilarity and decreasing the abundance of bacteria compared to PM-treated soil. The PM?+?100SMZ increased C mineralisation in the soil.  相似文献   

14.
《Ecological modelling》2005,186(2):212-220
This paper presents an emergy evaluation of the biogeochemical process of petroleum formation. Unlike the previous calculation, in which the transformity of crude oil was back calculated from the relative efficiency of electricity production and factors relating coal to transportation fuels and transportation fuels to crude oil, we analyzed the geochemical process of petroleum formation (naftogenesis) to determine the transformities of oil and natural gas. We assumed that the process of oil and gas production is a steady state process in which all the emergy required is captured in the initial input. For such a system, we can use the mass concentration of the initial input to determine the specific emergy and transformity of the products. We used the maximum photosynthetic yield in Joules of phytoplankton organic matter per Joule of sunlight as the starting point. From this initial assumption, we traced the energy transformations in the oil and gas formation process through photosynthesis, death and decay of the phytoplankton, and diagenesis to kerogen production and from kerogen through catagenesis to petroleum formation. Our results show that both methods converge to similar values for oil (∼54,200 solar emJoules per Joule (sej/J)) and petroleum natural gas (43,500 sej/J) increasing our confidence in the results of past emergy analyses and providing a firm basis for the calculation of transformities for oil and gas derivatives.  相似文献   

15.
Diurnal variations in aquatic systems may be a major factor influencing carbon cycling. However, few studies have examined diurnal variation on floodplains and wetlands, especially in the tropics. Stable isotope analysis of dissolved inorganic carbon (δ13CDIC) provides insight into the driving factors behind diurnal physio-chemical variability, but to date, the manual collection of large sample numbers at high temporal frequency has been prohibitive. Here, we report one of the first, high-resolution isotopic studies of δ13CDIC on a tropical floodplain using acidification-interface cavity ring-down spectrometry. Water samples were analysed for δ13CDIC and other water quality parameters at 15-min intervals for 24 h. Our results show significant diurnal variation in both DIC concentration and δ13CDIC. Maximum DIC concentration, recorded overnight, was approximately 100 % greater than during the day. Maximum DIC concentration coincided with minimum δ13CDIC as a result of shifting autotrophic/heterotrophic balance. Changes were significant over small time scales and showed CO2 gas evasion estimates could vary by as much as 50 % based on measurements taken less than 5 h apart. These data show that to accurately evaluate the role of tropical floodplains in global carbon dynamics, a comprehensive understanding of diurnal variation will be essential.  相似文献   

16.
Aliphatic hydrocarbons isolated from mussels collected over a 20 month period from three North Sea Forties field oil production platforms have been examined by capillary gas chromatography and gas chromatography‐mass spectrometry.

The biological hydrocarbons consist predominantly (300–700 μh g‐1 lipid) of C31 and C33 n‐alkenes with 2, 3 and 4 double bonds probably derived from a dietary intake of Emiliania huxleyi, a microscopic coccolithophorid alga. In some of the mussels C18, C20 and C22 n‐alkanes are present in unusually high abundance compared to their odd carbon number homologues. Possible reasons for this distribution are discussed.

The concentrations of fossil fuel hydrocarbons (mainly unresolved complex mixtures) in the mussels ranged from 330 to 5,298 μg g‐1 of lipid. No significant increase in values was detected two months after the start of discharge of treated Forties production water from the Forties D platform.

To determine the pollutant hydrocarbon sources, the sterane and terpane distributions of hydrocarbon fractions isolated from the mussels and from a number of fossil fuels, including Forties crude oil, were examined by mass fragmentography. The steranes in the mussels from the Forties C and D platforms contained higher proportions of regular 14α(H), 17α(H) components than Forties oil in which the steranes were mainly 13ß(H), 17α(H) diasteranes. In addition, the terpane distributions of the mussel fractions differed markedly from that of Forties crude oil, particularly in the relative abundance of diterpanes to triterpanes, which was higher in the mussel fractions than in the oil, and in the absence of 17α(H), 18α(H), 21ß(H)‐18, 30‐bisnorhopane, a known component of Forties crude. Furthermore, the ratio of C29 to C30 triterpanes was greater than unity in the mussels but much less than unity in the Forties oil. These data preclude Forties or other similar North Sea crudes as the major source of pollutant aliphatic hydrocarbons in the mussels. The relative concentrations and distributions of steranes and triterpanes suggest that the most likely source of pollutants is a Middle Eastern based oil derived either from rig activities, or from background pollution in the North Sea. The low concentration of ≥ C27 steranes in the more polluted mussels (e.g. Forties B; UCM > 200 ppm dry wt.) suggests that gas oils used on the platforms may be the major source of petrogenic hydrocarbons in these samples.  相似文献   

17.
The red algaGelidium sesquipedale (Clem.) Born. et Thur. has been cultured in chemostats to assess the effects of light quality and photon-fluence rate (PFR) on growth, photosynthesis and biochemical composition. Plants under blue and red light (BL and RL) showed higher growth rates than under white light (WL) of the same PFR (40 mol m–2 s–1). The light-saturated rate of photosynthesis was higher for algae grown under BL and RL than for algae grown under WL. When algae were transferred to WL of moderate PFR (100 mol m–2 s–1), the light-saturated rate of photosynthesis decreased, being higher in previously RL-grown algae than in previously BL- and WL-grown algae. The initial slope of photosynthesis-irradiance (PI) curves () was affected by PFR but not by light quality. Pigment content was little affected by light quality. Light-quality treatments also affected the biochemical composition of the alga; previous exposure to various light treatments activate or repress several metabolical pathways that are fully expressed in the subsequent phase of WL of moderate PFR. Thus, phycobiliproteins and soluble proteins increased for previously BL- and RL-grown algae, whereas insoluble carbohydrate concentration was reduced, indicating a change of the C-partitioning between carbon compounds and organic nitrogen compounds. Inorganic nitrogen metabolism was also affected by light: under WL of moderate PFR, NO3 was totally depleted from sea water, and maximal values of NO3 uptake were recorded. In addition, neither NO2 nor NH4 + was released. However, when algae were transferred to a low PFR, there was a drastic reduction of NO3 uptake under WL, which only partially recovered over time. It was accompanied by the release of NO2 , but not NH4 +, to the culture medium. Under BL and RL, however, there was a transient enhancement of NO3 uptake that was followed by a net release of NO2 and NH4 . Growth rates were not correlated with PFR. This could be due to the the dynamics of internal carbon mobilization and accumulation in the algae. When algae were exposed to a moderate PFR of WL, carbon requirements for growth were satisfied by photosynthesis. Thus, there was a net accumulation of carbon in the tissue. In contrast, when algae were exposed to low PFRs of either WL, BL or RL, observed growth rates could not be maintained by photosynthesis and carbon was mobilized.  相似文献   

18.
Resolving CO2 and methane hydrate formation kinetics   总被引:1,自引:0,他引:1  
We analyse the kinetics of CO2 and methane hydrate formation. The characteristic formation times are associated with different steps of the formation process. Conditions for minimising these rate times are identified while maintaining a regime where CO2 hydrate is formed and methane remains predominantly gaseous. This involves a rapid pressurisation routine and accesses points well above the phase boundary in order to enable faster kinetics. Conditions for optimising rates and times, to obtain maximum CO2 uptake with respect to CH4, were identified as (1) stirring faster than 1,000 rpm, (2) rapid pressurisation to a partial pressure of around 50 bar for CO2 and (3) re-use of contaminated as opposed to fresh water.  相似文献   

19.
本文选择了紫背浮萍、四尾栅藻、蚤状溞和稀有鮈鲫4种本土水生生物,开展了阳离子表面活性剂、织物三防整理剂、C4三防整理剂和C6三防整理剂4种全氟辛烷磺酸盐(PFOS)替代品的安全性评估,为筛选理想PFOS化学替代品提供科学依据。急性毒性结果发现阳离子表面活性剂对4种水生生物均未显示出急性毒性;织物三防整理剂、C4三防整理剂和C6三防整理剂对蚤状溞的LC50值分别为17.97、64.61和85.58 mg·L-1,显示出低的急性毒性。另外,织物三防整理剂对四尾栅藻的半数抑制浓度(EC50)值为88.32 mg·L-1,而对稀有鮈鲫半致死浓度(LC50)值为14.79 mg·L-1,均存在急性毒性。短期生长抑制试验结果发现阳离子表面活性剂、织物三防整理剂、C4三防整理剂和C6三防整理剂对稀有鮈鲫生长抑制最低可见效应浓度(LOEC)值分别为20、1.5、100和50 mg·L-1,表明4种PFOS替代品均显示低慢性毒性。急慢性综合分析可知C4和C6三防整理剂相对较安全,可能成为理想的PFOS替代品。  相似文献   

20.
PFOS及其4种替代品对两栖动物非洲爪蟾和黑斑蛙蝌蚪的急性毒性结果为:用调聚法合成的织物三防整理剂对非洲爪蟾蝌蚪和黑斑蛙蝌蚪的96h-LC50分别为8和21mg·L-1,而PFOS对两种蝌蚪的96h-LC50分别为92和81mg·L-1。此实验结果说明织物三防整理剂的急性毒性高于PFOS。用电解氟化法合成的C4、C6织物三防整理剂和50%的全氟丁基有机铵盐阳离子表面活性剂浓度在100mg·L-1时,对两种蝌蚪都没有毒性。这说明,从急性毒性的角度,C4、C6织物三防整理剂和表面活性剂可作为PFOS的替代品使用,但是织物三防整理剂的急性毒性比PFOS大,作为替代品使用应慎重考虑。另外,PFOS和织物三防整理剂对黑斑蛙蝌蚪的急性毒性与对非洲爪蟾蝌蚪的急性毒性存在差异。出于保护我国本土两栖动物的目的,使用黑斑蛙开展毒性评价比使用非洲爪蟾更有现实意义。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号