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1.
The adsorption isotherms, the constants of the Dubinin—Radushkevich plots, and the constants of the Langmuir plots of chlorofluorocarbon (CFC) and CFC replacements on high‐surface area activated carbon were investigated to estimate the recovery efficiency of CFC and CFC replacements. The adsorption and desorption of HFC134a on a high‐surface area activated carbon was much easier than that of CFC 113 and the CFC replacements. The recovery efficiency of CFC replacements depends on the hydrogen atoms in molecule. It is possible that the saturated amount adsorbed in the pores or on the surface of the activated carbon could be evaluated by the Ws constant of the the Langmuir equation and the Wo constant of the Dubinin‐Radushkevich equation. The a constant of the Langmuir equation and the BEo constant of the Dubinin‐Radushkevich equation depend on the molecular composition.  相似文献   
2.
The leaching behavior of dioxins from landfill containing bottom ash and fly ash from municipal solid waste incineration has been investigated by leaching tests with pure water, non-ionic surfactant solutions, ethanol solutions, or acetic acid solutions as elution solvents for a large-scale cylindrical column packed with ash. Larger amounts of dioxins were eluted from both bottom ash and fly ash with ethanol solution and acetic acid solution than with pure water. Large quantities of dioxins were leached from fly ash but not bottom ash by non-ionic surfactant solutions. The patterns of distribution of the dioxin congeners in the leachates were very similar to those in the bottom ash or fly ash from which they were derived.  相似文献   
3.
In order to separate and reuse heavy and alkali metals from flue gas during sewage sludge incineration, experiments were carried out in a pilot incinerator. The experimental results show that most of the heavy and alkali metals form condensed phase at temperature above 600 degrees C. With the addition of 5% calcium chloride into sewage sludge, the gas/solid transformation temperature of part of the metals (As, Cu, Mg and Na) is evidently decreased due to the formation of chloride, while calcium chloride seems to have no significant influence on Zn and P. Moreover, the mass fractions of some heavy and alkali metals in the collected fly ash are relatively high. For example, the mass fractions for Pb and Cu in the fly ash collected by the filter are 1.19% and 19.7%, respectively, which are well above those in lead and copper ores. In the case of adding 5% calcium chloride, the heavy and alkali metals can be divided into three groups based on their conversion temperature: Group A that includes Na, Zn, K, Mg and P, which are converted into condensed phase above 600 degrees C; Group B that includes Pb and Cu which solidify when the temperature is above 400 degrees C; and Group C that includes As, whose condensation temperature is as low as 300 degrees C.  相似文献   
4.
Sakurai T  Suzuki N  Morita M 《Chemosphere》2002,46(9-10):1359-1365
Past dioxin (coplanar polychlorinated biphenyl (Co-PCB), 2,3,7,8-substituted polychlorinated dibenzo-p-dioxin (PCDD) and 2,3,7,8-substituted polychlorinated dibenzofuran (PCDF)) fluxes recorded in dated aquatic-sediment cores were analyzed using principal component analysis (PCA). The data set consisted of samples from four cores collected from the Kanto region of Japan. Time trends and spatial differences in the dioxin flux were examined, and the potential relationship to emission sources was investigated. Twenty-five compounds and 58 core slices, corresponding to the later half of the 20th century, were subjected to the analysis. The PCA of both log-transformed and maximum-value-standardized data successfully divided the dioxin compounds into a small number of groups, and three similar clusters of Co-PCBs, PCDDs and penta- to hepta-CDFs were identified. PCB formulations used in the past are judged to have been responsible for the major part of the Co-PCB flux recorded in the sediment cores. However, the relationship to emission sources needs further investigation. It is suggested that most 2,3,7,8-substituted PCDDs and PCDFs are different from Co-PCBs in their emission sources or movements in the environment. The subcore clusters obtained from the PCA of log-transformed data show that the cores from different sampling areas exhibited distinct dioxin fluxes and compositions. Common time trends among the cores were more effectively summarized by the PCA of maximum-value-standardized data focusing on relative time trends. PC scores show that recently the flux of each dioxin compound in the four cores has been generally declining after having reached a peak.  相似文献   
5.
Yasuhara A  Katami T  Shibamoto T 《Chemosphere》2006,62(11):1899-1906
Polyvinylidene chloride (PVDC; polymer of 1,1-dichloroethylene) was combusted with paper in a well-controlled, small-scale incinerator at an average grate temperature of 700 °C, and then dioxins (PCDDs, PCDFs, and coplanar-PCBs) formed in the exhaust gases were analyzed by gas chromatography/mass spectrometry. PVDC lowered the combustion temperature due to its less flammable character. The amount of total dioxins (PCDDs + PCDFs + coplanar-PCBs) formed in the exhaust gas was 58.0 ng/g of a combustion sample and its toxicity equivalency quantity (TEQ) value was 0.64 ng-TEQ/g. The amount of PCDDs formed in the sample ranged from 2.33 ng/g (Cl8-isomer) to 0.048 ng/g (Cl1-isomer). The lower the number of chloride, the less production of PCDDs. On the other hand, there was no relation between the number of chloride and PCDF formation. The amount of PCDFs formed in the sample ranged from 8.02 ng/g (Cl2-isomer) to 4.46 ng/g (Cl8-isomer). A polyvinylchloride (PVC) sample produced 207 ng/g of total dioxins and a PVDC sample produced 57.4 ng/g of total dioxins when they were combusted under the same conditions. An approximately equal composition of dioxin isomers was formed from PVDC and PVC samples. Paper was found to contribute to PCDF formation when it was combusted with plastics.  相似文献   
6.
A study of the dietary intake of dioxins, consisting of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dioxin-like PCBs) through foods retailed in the metropolitan Tokyo area from 1999 to 2004 was carried out by the total diet-market basket method on the basis of food classification (14 groups) and the data on food consumption in the Tokyo region obtained from the Japan Nutrition Survey. The daily intake of dioxins per kg of body weight for a 50 kg average adult body was 2.18 pg TEQ/kg/day in 1999, 1.87 pg TEQ/kg/day in 2000, 1.25 pg TEQ/kg/day in 2001, 1.60 pg TEQ/kg/day in 2002 and 2003 and 1.55 pg TEQ/kg/day in 2004, respectively. These amounts were less than the tolerable daily intake (TDI) of 4 pg TEQ/kg/day for dioxins established in Japan. The dioxins taken daily through fish and shellfish (group 10) accounted for more than 50% of sum WHO-TEQs. In addition, more than 90% of the daily intake of dioxins was taken through fish and shellfish (group 10), meat and eggs (group 11), milk and dairy products (group 12). Also, this study clearly showed that the ratio of dioxin-like PCBs in the daily intake of dioxins was increasing yearly because the reduction rate of dioxin-like PCBs was lower than that of PCDDs and PCDFs in foods.  相似文献   
7.
Perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) have recently received attention due to their widespread contamination in the environment, as well as in wildlife and humans. We measured the PFOS and PFOA concentrations in historically recorded human serum samples at an age range between 20 and 59 years collected in Kyoto, 20 persons per each time point (n=100), and also the PFOS and PFOA concentrations in human serum samples at an age range between 20 and 59 years from 10 locations throughout Japan (n=200). The historical samples collected from 1983 to 1999 demonstrated that the PFOA concentrations in males and females from Kyoto have increased 4.4-fold and 4.3-fold at a rate of increase of 0.49 ng/ml/year and 0.42 ng/ml/year, respectively. In contrast, serum concentrations of PFOS reached a plateau in the late 1980s. There are also regional differences in both the PFOS and PFOA serum concentrations. The concentrations in serum [geometric mean (geometric standard deviation)] (ng/ml) in 2003-2004 ranged from 7.6(1.6) in the town of Matsuoka in Fukui prefecture to 27.8(1.6) in Kyoto city, and ranged from 2.3(1.5) in Matsuoka to 14.5(1.3) in Osaka city for PFOS and PFOA, respectively.  相似文献   
8.
The food industry is one of the world's largest industrial sectors, hence a large contributor of greenhouse gases (GHG) which cause global warming. This study evaluates the life cycle of various types of meat to determine if the GHG emission from the meat industry in Japan could be reduced if the population makes different dietary choices. It was confirmed that the GHG emission of beef was greater than that of pork or chicken. The GHG emission from meat in general also depends on the per capita caloric intake (if meat supplies the recommended animal protein or contributes to it at the present rate). In a healthy and balanced diet (9.2 MJ i.e., 2200 kcal in total, where either mixed meat or chicken or pork or beef contributes 2.2%), the GHG emission is estimated to be 0.28 or 0.17 or 0.15 or 0.77 kg CO? eq/person/day, respectively. A change in consumption patterns (from beef to chicken or pork) and the adoption of a healthy and balanced diet would help to abate about 2.5-54.0 million tons (CO? eq) produced by the meat industry each year in Japan.  相似文献   
9.
Increases of low-latitude species in various sea areas and poleward shifts of ranges of many species have been reported and linked to warming environments. To examine the generality of these trends for mollusks, we conducted 7 quadrat surveys during 1978–2006 on Pacific rocky shores in Japan (26.6–45.0°N). Results showed that the dominance of southern species increased on 11 of the 15 shores in a southern, warming sea area but on only 1 of the 6 shores in a northern area with no warming trend. The latitudes of species ranges increased on average but showed large interspecific variations which showed a weak, positive correlation with interspecific taxonomic distance. The differences of these results from the previously reported trends are discussed in relation to the unique current patterns in our study area and the phylogenetic constraints of species-specific responses to a warming environment.  相似文献   
10.
We investigated the respiratory uptake kinetics of polychlorinated biphenyls (PCBs), organohalogen pesticides (OCPs), polycyclic aromatic hydrocarbons (PAHs), and 2,2′,4,4′-tetrabrominated diphenyl ether (BDE #47) in a marine benthic fish, Pseudopleuronectes yokohamae. The respiratory uptake efficiencies (EW) of the chemicals, of which there have been no reports for the majority of persistent organic pollutants (POPs), were obtained by measuring the respiratory uptake rate constants (k1) and the oxygen consumption rates of fish. Fish were exposed to water in which these chemicals were dissolved at environmentally relevant concentrations for 28 d, followed by 168 d of depuration in clean seawater. The k1 and EW values for 99 compounds were obtained, and they ranged from 2000 to 42 000 L kg-lipid−1 d−1 and from 0.060 to 1.3, respectively. The EW values of the chemicals, except for PAHs, tended to increase with increasing values of the log octanol–water partition coefficients (KOW) of the chemicals up to a log KOW of 5. For log KOW in the range 3–5, the EW values in this study were much lower than those in a published study (about one-third). As a result of analysis by a two-phase resistance model, the resistance of transport rates to the lipid phase in this study was lower than was the case in the published study. These findings indicate that the EW predicted by the published study for log KOW in the range 3–5 may differ among fish species and water temperature, and further study is needed.  相似文献   
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