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261.
考察了在干燥气氛下不同氧化物催化剂对非热等离子体催化降解甲苯的影响。从甲苯降解率、碳平衡、CO2选择性和O3去除4个方面,对比了氧化物催化剂的介电性能、表面供氧能力和比表面积与多孔结构对反应产生影响的强弱。结果表明,催化剂的介电性能有利于甲苯降解率、碳平衡和O3产量的提高,但对CO2选择性和O3去除的影响极小;一定能量密度下,催化剂比表面积与多孔结构对CO2选择性和O3去除所产生的影响要强于介电性能;催化剂表面供氧能力可明显促进反应的进行,其对反应所产生的影响要强于比表面积与多孔结构。 相似文献
262.
263.
对杭州市环保系统的人才总量、学历结构、专业结构、职称结构和年龄结构等方面作了较详细的分析;针对杭州市环保系统存在的人才总量不足、结构分布不合理和高层次人才匮乏等问题,提出了引进高层次人才、加强教育培训、壮大基层队伍等对策。 相似文献
264.
运用遥感动态监测与地理信息系统技术相结合的方法,以2005年和2009年遥感解译数据、土地侵蚀数据及环境统计数据为数据源,依据《生态环境状况评价技术规范(试行)》(HJ/T192-2006),对山东省17个城市生态环境质量现状及动态变化趋势进行了评价。结果表明:2009年17个城市生态环境状况指数在59.81~78.08之间,生态环境质量状况总体良好;2005-2009年17城市生态环境状况指数变化值在0.06~3.5之间,生态环境质量状况基本稳定。 相似文献
265.
Pentachlorobenzene (PeCB) in simulated flue gas was destructed by a commercial V2O5-WO3/TiO2 catalyst in this study. The effects of reaction temperature, oxygen concentration, space velocity and some co-existing pollutants on PeCB conversion were investigated. Furthermore, a possible mechanism for the oxidation of PeCB over the vanadium oxide on the catalysts was proposed. Results show that the increase of gas hourly space velocity (GHSV) and the decrease of operating temperature both resulted in the decrease of PeCB removal over the catalyst, while the effect of the oxygen content in the range of 5-20% (v/v) on PeCB conversion was negligible. PeCB decomposition could be obviously affected by the denitration reactions under the conditions because of the positive effect of NO but negative effect of NH3. The introduction of SO2 caused the catalyst poisoning, probably due to the sulfur-containing species formed and deposited on the catalyst surface. The PeCB molecules were first adsorbed on the catalyst surface, and then oxidized into the non-aromatic acyclic intermediates, low chlorinated aromatics and maleic anhydride. 相似文献
266.
Effect of inoculation methods on the composting efficiency of municipal solid wastes 总被引:3,自引:0,他引:3
Four types of inoculation methods were studied during the composting of municipal solid wastes and dry grass (MSWG). The methods included a control group as well as initial-stage, two-stage, and multi-stage inoculations. Fulvic acids were extracted from the composting materials and characterized by spectroscopic techniques. The results showed that inoculation of microbes in MSWG enhanced the biodegradation of aliphatics, proteins, and polysaccharides. The inoculation also increased the molecular weight, humic- and fulvic-like compound content, as well as humification degree of the composting products. The inoculation of microbes in MSWG significantly improved composting process and efficiency. The improvement efficiency was in the order of initial-stage < two-stage < multi-stage inoculations. Inoculation of microbes based on composting organic matter composition and temperature enhanced composting efficiency. 相似文献
267.
Tao Tang Kun QianTianyu Shi Fang WangPingliang Li Jianqiang LiYongsong Cao 《Chemosphere》2012,89(11):1419-1425
Quinestrol is synthetic estrogen used in contraceptive and hormone replacement therapy and occasionally for treating breast cancer and prostate cancer. It can make its way into the environment through sewage discharge and waste disposal produced by human excretions. In this study, the photodegradation kinetics of quinestrol in various conditions was investigated by UV and solar irradiation. The affecting factors were studied including concentration of hydrogen peroxide, different water types, and the initial concentrations of quinestrol. Concurrently, the transformation products and presumed pathways of quinestrol in distilled water by UV irradiation were identified and proposed. The results showed that the degradation of quinestrol in both irradiation conditions followed the pseudo-first-order kinetics. More rapid degradation was observed by UV irradiation (k = 0.018 min−1) than solar irradiation (k = 0.004 h−1), and the photodegradation rate of quinestrol depended on the concentration of hydrogen peroxide, the initial concentration of quinestrol and water types. The transformation products of quinestrol in distilled water were identified by gas chromatography/mass spectrometry. When exposed to UV irradiation, quinestrol in aqueous solution was rapidly degraded, giving at least ten photodegradation products. The chemical structures of ten degradation products were identified on the basis of mass spectrum interpretation and literature data. 相似文献
268.
Zushi Y Ye F Motegi M Nojiri K Hosono S Suzuki T Kosugi Y Yaguchi K Masunaga S 《Chemosphere》2012,88(11):1353-1357
In this study, we analyzed over 30 types of PFCs, including precursors in both the dissolved phase and particle solid phase, in 50 samples of river water collected from throughout the Tokyo Bay basin. PFCs were detected in suspended solids (SSs) at levels ranging from <0.003-4.4 ng L(-1) (0.11-2470 ng g(-1) dry weight). The concentrations of PFCs in the SS were one to two order(s) of magnitude lower than those of PFCs in the dissolved phase. Relatively high levels of PFCs (total of 35 PFCs) in SS were observed in urbanized areas. The concentration of PFCAs, including PFOA and PFNA, were significantly correlated with the geographic index as artificial area (R(2) of the linear regression curve in a double logarithmic plot: 0.09-0.55). Conversely, PFOS and FOSA were significantly correlated with the arterial traffic area (R(2) in a double logarithmic plot: 0.29-0.55). Those spatial trends were similar to the trends in dissolved PFCs. We estimated the loading amount of PFCs into Tokyo Bay from six main rivers and found that more than 90% of the total PFCs reached Tokyo Bay in the dissolved phase. However, 40.0-83.5% of the long chain PFCAs (C12-C15), were transported as particle sorbed PFCs. Rain runoff events might increase the loading amount of PFCs in SS. Overall, the results presented herein indicate that greater attention should be given to PFCs, especially for longer chain PFCs in SS in addition to dissolved PFCs. 相似文献
269.
Fang H Tang FF Zhou W Cao ZY Wang DD Liu KL Wu XW Yu YL 《Journal of environmental science and health. Part. B》2012,47(2):104-110
The effects of repeated applications of the fungicide triadimefon in agricultural soil on the microbial functional diversity of the soil and on the persistence of the fungicide in the soil were investigated under laboratory conditions. The degradation half-lives of triadimefon at the recommended dosage, simulated by a first-order kinetic model, were 23.90, 22.95, and 21.52 days for the first, second, and third applications, respectively. Throughout this study, no significant inhibition of the Shannon-Wiener index (H') was observed. However, the Simpson index (1/D) and the McIntosh index (U) were obviously reduced (p ≤ 0.05) during the initial 3 days after the first triadimefon application and thereafter, gradually recovered to or exceeded the level of the control soil. A similar trend in variation but with a faster recovery in the 1/D and U was observed after the second and third triadimefon applications, respectively. Taken together, the above results indicate that the repeated application of triadimefon enhanced the degradation rate of the fungicide and the recovery rate of the soil microbial functional diversity. It is concluded that repeated triadimefon applications in soil have a transient or temporary inhibitory effect on soil microbial communities. 相似文献
270.
Tian Z Cao G Shi J McCallum I Cui L Fan D Li X 《Environmental science and pollution research international》2012,19(5):1364-1374