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1.
《国际环境与污染杂志》2011,10(2):304-314
This paper investigates some of the reflectivity characteristics that clouds (when modelled as solid bodies) must exhibit to be compatible with observations that the reflecting surface of a cloud (i) appears almost equally bright across its face, (ii) is brightest when the cloud is opposite to the Sun but decreases in brightness as the cloud moves to other positions and (iii) increases in brightness with increasing optical thickness of the cloud in the observer's line of sight. These observations, respectively, are shown to imply that the peak value of the bidirectional total reflectivity from a cloud surface (i) increases in inverse proportion to the cosine of the angle between the Sun and the normal to the cloud surface, as the incident angle increases, (ii) appears to be directed back in the direction of the incident radiation, and (iii) increases as optical thickness of the cloud in the observer's line of sight increases. The results could have application in many fields (e.g. modelling diffuse radiance distributions for cloudy skies). 相似文献
2.
活性炭三维电极法对印染废水的处理研究 总被引:4,自引:0,他引:4
对三维电极方法处理印染废水进行了实验研究,初步探讨了活性炭三维电极法处理印染废水的机理,对影响处理效果的各种要素,如反应时间、槽电压和pH值等进行了条件实验,得出了活性炭三维电极法处理印染废水的最佳运行条件为:停留时间120-180 min,槽电压25~30 V,进水pH值6.5~7.5。结果表明,该反应器能有效地降低废水色度,有较高的COD去除效率,并能提高印染废水的可生化性。 相似文献
3.
Volker Berding Stefan Schwartz Michael Matthies 《Environmental science and pollution research international》1999,6(1):37-43
The interdependencies of parameters applied in the models of EUSES are visualised in a directed connectivity graph. The parameters
(inputs, defaults, state variables, outputs) are represented by boxes (nodes) and their relations by lines (edges). The visualisation,
on the one hand, clarifies the complexity of the models in EUSES and, on the other hand, creates an overview and transparency.
The parameters’ relations to each other can be recognised faster, and the models can be better understood. The complexity
was quantified by the number (variety), kind (substance parameter, physico-chemical parameter, concentration, other parameters),
and depth (dimension) of the parameter and the number of relations (connectivity). The variety of EUSES (without the modelsSimple Treat andSimple Box whose interior structure is not documented and without the effect and risk characterisation) amounts to 466, the connectivity
to 961, and the maximal dimension is 21. 相似文献
4.
Árpád Ambrus 《Journal of environmental science and health. Part. B》2013,48(3):435-442
Abstract A computer model was used to take random samples from primary sample populations obtained from field trials to simulate the uncertainty of sampling for residue analysis of plant commodities and soil. The results indicate about 40%, 30% and 20% relative uncertainty when random samples of size 5, 10 and 25 are taken respectively, from a single lot. Therefore the sample size should be the same for establishing and enforcing legal limits. 相似文献
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造纸废水混凝处理中SFT助凝替代性研究 总被引:1,自引:0,他引:1
中小造纸厂废水处理常用PAC作混凝剂 ,PAM作助凝剂。由于PAM成本很高 ,影响了处理设备的投运率。用超细滑石粉 (SFT)替代PAM助凝 ,与混凝剂PAC配合 ,其混凝处理效果基本相当 ,但是处理成本降低 0 .10元 /m3 。由于SFT属环境无害材料 ,不会给排泥带来二次污染 相似文献
7.
Geochemical evidences of the anthropogenic alteration of trace metal composition of the sediments of Chiricahueto marsh (SE Gulf of California) 总被引:8,自引:0,他引:8
Soto-Jiménez M Páez-Osuna F Ruiz-Fernández AC 《Environmental pollution (Barking, Essex : 1987)》2003,125(3):423-432
Seven sediment cores (60-80 cm) were collected at Chiricahueto marsh, a salt marsh influenced by agrochemical, domestic and industrial effluents. The concentrations of Ag, Al, Cd, Co, Cu, Fe, Li, Mn, Pb, V and Zn were studied in the solid phase at each 1-cm section. The profiles of Ag, Cd, Cu, Mn, Ni, Pb and Zn showed a slight recent pollution in the site with enrichment and anthropogenic factors higher than unity; and correlation analysis indicated a direct association with organic carbon. Al, Co, Cr, Fe, Li, and V concentration profiles displayed a negative correlation with organic C and positive with mud content and no consistent enrichment at surface. Based on the principal component analysis and correlation analysis, two principal groups of metals were identified. The first group includes Al, Co, Cr, Fe and Li, that are derived predominantly from the weathering of parent materials in the local bedrock; and the second group include most of the metals, which were relatively enriched at surficial sediments, that are produced mainly by anthropogenic activities such as agriculture (Cd, Cu and Zn), sewage effluents (Ag, Cd, Cu, Ni, Pb and Zn) and in lesser extent atmospheric deposition (Cd and Pb). 相似文献
8.
《Atmospheric environment(England)》1989,23(9):1945-1948
In order to elucidate the reaction mechanism of the ozonolysis of acrylonitrile in the liquid phase, characterization of reaction products has been attempted. One of the products, which was volatile, has been found to be formaldehyde by derivatizing with dimedone. The infrared and mass spectra of the derivative corresponded with that of alkylidene dimedone. Three other reaction products were isolated by TLC using silica gel, CHCl3:MeOH (80:20). These have been tentatively identified as glyoxal, epoxide of acrylonitrile and acetamide from their mass spectra. Based on these findings a reaction pathway for the formation of formaldehyde is proposed to be that described by Criegee. 相似文献
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J. P. Franey T. E. Graedel 《Journal of the Air & Waste Management Association (1995)》2013,63(6):644-648
The corrosion films that form on metals and alloys during field exposure are generally chemical mixtures. It is clear that the formation of such films requires the presence of mixtures of atmospheric corrosive gases, or of a combination of corrosive gases and atmospheric aerosol particles. Thus, laboratory experiments designed to reproduce field effects must involve mixtures of corrosive constituents. In this paper we review the mixed corrodent experiments of ourselves and others, describe the synergistic effects of mixtures of pollutants on a variety of metals, and present the necessary ingredients for experiments designed to simulate the interactive effects of atmospheric corrosive constituents. 相似文献
12.
进行了添加乙醇作为碳源强化油制气废水生物降解的研究,并利用GC/MS分析对油制气废水中芳烃类化合物的降解进行了初步研究。研究表明,共代谢基质乙醇的加入,可使菌种S-2、Y-3、XH-3、M-3对COD、氨氮、可萃取有机物等指标的去除率分别提高17.6%~25.6%、34.9%~42.8%、10.4%~14.2%;但在所采用的时间范围内,酚类化合物的去除率降低;芳烃类化合物的去除率提高15.4%~21.2%。除了维持无共代谢条件下对芳环数≤3的芳烃类化合物的良好降解能力外,对芳环数为4~6的化合物降解能力也有所提高。 相似文献
13.
Yufei Hu Jun Chen Huihui Fan Ping Xie Jun He 《Environmental science and pollution research international》2016,23(8):7211-7219
Cyanobacterial blooms-produced microcystins are secondary metabolites which can accumulate in the food chain and contaminate water, thus posing a potential threat to the health of aquatic animals and even humans. Microcystin toxicity affects not only the liver but also the other organs, i.e., the brain. The serious neurotoxicity effects caused by microcystins then lead to various symptoms. This review focuses on the neurotoxicity of microcystins. Microcystins can cross blood-brain barrier with the transport of Oatps/OATPs, causing neurostructural, functional, and behavioral changes. In this review, potential uptake mechanisms and neurotoxicity mechanisms are summarized, including neurotransmissions, neurochannels, signal transduction, oxidative stress, and cytoskeleton disruption. However, further researches are needed for detailed studies on signaling pathways and the downstream pathways of neurotoxicity of microcystins. 相似文献
14.
Zhen-Zhen Xie Lin Wang Ge Cheng Yi-Bo Zhang 《Journal of the Air & Waste Management Association (1995)》2016,66(12):1224-1236
A specific type of material, activated carbon fiber (ACF), was modified by SiO2, and the final products ACF-x were obtained as ACF-12.5, ACF-20, ACF-40, and ACF-80 according to different dosages of tetraethoxysilane (TEOS). The modified material on the ACF surface had a significant and smooth cover layer with low content of silica from scanning electron microscope (SEM) image. The modified ACF-x showed the stronger hydrophobicity, thermal stability, and adsorption capacity, which had almost no effect in the presence of water vapor and no destruction in multiple cycles. ACF-20 was proven as the most efficient adsorbent in humid conditions. The dual-function system composed of the regenerative adsorbents and the combustion catalyst would be efficient in consecutive toluene adsorption/oxidation cycles, in which the combustion catalyst was prepared by the displacement reaction of H2PtCl6 with foam Ni. Therefore, the adsorption/catalytic oxidation could be a promising technique in the indoor air purification, especially in the case of very low volatile organic compound (VOC; toluene) concentration levels.
Implications: Exploring highly effective adsorptive materials with less expensive costs becomes an urgent issue in the indoor air protection. ACF-20 modified by SiO2 with Pt/Ni catalysts shows stronger hydrophobicity, thermal stability, and adsorption capacity. This dual-function system composed of the regenerative materials and the combustion catalyst would be a promising technique in the indoor air purification, especially in the case of removal of very low concentration of toluene. 相似文献
15.
Marrs RH Williams CT Frost AJ Plant RA 《Environmental pollution (Barking, Essex : 1987)》1989,59(1):71-86
With increasing use of herbicides there has been growing concern that spray drift from treated land will affect vegetation on adjacent nature reserves and other areas of high conservation interest. A preliminary attempt was made to assess this risk by placing a range of native plant species at different distances downwind from standardised drift events and assessing lethal effects and sublethal damage. Five herbicides were tested: asulam, 'Finesse' (chlorsulfuron + metsulfuron-methyl), glyphosate, MCPA and mecoprop. Applications were made at the appropriate time of years for each herbicide (autumn, spring and summer), and at both low and high wind speeds. The maximum safe distance at which no lethal effects were found was 6 m from the sprayer, but for most herbicides the distance was 2 m or less. Generally, damage symptoms were found at greater distances than lethal effects, but in most cases there was rapid recovery by the end of the growing season. These observations are consistent with drift-deposition models, in which the fallout of herbicide droplets has been measured. It is suggested that buffer zones surrounding nature reserves should be in the order of 5-10 m for ground sprayers to minimise the risk of herbicide impacts on these habitats. 相似文献
16.
Saeki K Nakajima M Loughlin TR Calkins DC Baba N Kiyota M Tatsukawa R 《Environmental pollution (Barking, Essex : 1987)》2001,112(1):19-25
Silver in the three species of pinnipeds [northern fur seal (Callorhinus ursinus), Steller sea lion (Eumetopias jubatus), and harbor seal (Phoca vitulina)] caught in the North Pacific Ocean were analyzed using inductively coupled plasma-mass spectrometry, in order to understand accumulation and distribution of silver in pinnipeds. In northern fur seals, relatively high concentrations of silver were observed in the liver and body hair. Some 70% of the silver burden was concentrated in the liver. Hepatic silver concentrations were significantly correlated to age in northern fur seals (r = 0.766, P < 0.001, n = 49) and Steller sea lions (r = 0.496, P < 0.01, n = 28). Levels of silver concentrations per wet weight (microgram g-1) in the three pinnipeds ranged from 0.04 to 0.55 for northern fur seals, from 0.1 to 1.04 for Steller sea lions and from 0.03 to 0.83 for harbor seals. Silver concentrations in liver for all pinnipeds were significantly correlated with mercury, and selenium (P < 0.001). Molar ratios between silver to selenium approximated 1:180 in northern fur seals, 1:120 in Steller sea lions, and 1:60 in harbor seals. The silver-mercury molar ratios were approximately 1:170 in northern fur seals, and 1:80 both in the other species. Increase in silver accumulation in the liver was caused by the retention in nuclei and mitochondria fraction together with mercury and selenium in the cells of northern fur seals. 相似文献
17.
Distribution of heavy metal contents of urban soils in parks of Seville 总被引:28,自引:0,他引:28
Several metals in urban soils of Seville were extracted by two methods, which respectively give estimates of the available and ‘quasi total’ contents. Although the soils did not show strong heterogeneity in their general properties, high dispersion of the contents in those metals with greater relative availability, Cu, Pb and Zn, as compared to others suggested that pollution with these three metals could occur in some sampling sites. It was shown that the contents in these metals tend to increase as the historic quarters of the city are approached. Using reference values given by the Québec Ministry of Environment it was shown that those green areas closer to the historic centre present contents in Pb, Zn and particularly Cu that often exceed the acceptable limits for residential, recreational and institutional sites. From background contents for Seville soils estimated from a park located on the outskirts, a pollution load index (PLI) for each sampling site was calculated for the set of these three metals. It was shown that the PLI tends to increase as traffic density increases and as distance from main traffic decreases, but poor regressions were obtained, suggesting that other variables different from traffic should be considered. 相似文献
18.
The salting-out effect by seawater constituents on the water solubilities of 11 aromatic compounds, anthracene, pyrene, phenanthrene, biphenyl, naphthalene, p-nitrotoluene, p-toluidine, o-nitrophenol, m-nitrophenol, p-nitrophenol and phenol was investigated. A best fit equation (r = 0.965) for the salting-out parameters, K, and distilled water solubilities, So, at 20°C was found to be K = ?0.0298 log So + 0.114. Seawater solubilities, S, predicted for solutions of ionic strength, I, using the equation log S = (0.0298 I + 1) log So ? 0.114 I were in agreement with observed values within 13 % (average 4.8 %) and there were no significant differences between values from the Pacific Ocean seawater and those from 35 o/oo NaCl solutions. It was concluded that dissolved organic matter in seawater had an insignificant effect for the test chemicals. 相似文献
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Evaluation of the presence of drugs of abuse in tap waters 总被引:1,自引:0,他引:1
A total of seventy samples of drinking water were tested for non-controlled and illicit drugs. Of these, 43 were from Spanish cities, 15 from seven other European countries, three from Japan and nine from seven different Latin American countries. The most frequently detected compounds were caffeine, nicotine, cotinine, cocaine and its metabolite benzoylecgonine, methadone and its metabolite EDDP. The mean concentrations of non-controlled drugs were: for caffeine 50 and 19 ng L−1, in Spanish and worldwide drinking water respectively and for nicotine 13 and 19 ng L−1. Illicit drugs were sparsely present and usually at ultratrace level (<1 ng L−1). For example, cocaine has mean values of 0.4 (Spain) and 0.3 ng L−1 (worldwide), whereas for benzoylecgonine, these mean values were 0.4 and 1.8 ng L−1, respectively. Higher concentrations of benzoylecgonine were found in Latin American samples (up to 15 ng L−1). No opiates were identified in any sample but the presence of methadone and EDDP was frequently detected. Total mean values for EDDP were 0.4 ng L−1 (Spain) and 0.3 ng L−1 (worldwide). Very few samples tested positive for amphetamines, in line with the reactivity of chlorine with these compounds. No cannabinoids, LSD, ketamine, fentanyl and PCP were detected. 相似文献