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141.
我校生态综合实验室由实验室、仪器设备储藏室和教师预备室组成。本文针对该实验室在运行中由于教学任务的逐年增加导致的实验室软硬件建设相对滞后等问题,在实验室的管理建设方面提出了提高综合利用率等建议。 相似文献
142.
Mineralization of 2,4-dichlorophenol (DCP) was studied by ozone with Mn(2+) as an ozonation catalyst. Laboratory scale semi-batch ozonation experiments were conducted at room temperature. The results showed that trace amount of Mn(2+) accelerated the mineralization of DCP. Total organic carbon removal rate was independent on Mn(2+) dosage at its range of 0.1-0.5 mgL(-1). Dissolved ozone concentration in the solution remained low level in the catalytic ozonation process, which indicated that Mn(2+) catalyzed decomposition of ozone. DCP mineralization was inhibited in catalytic ozonation by the addition of carbonate. Electron spin resonance/spin-trapping technique was used to determine hydroxyl radicals, and the results showed that larger amounts of hydroxyl radicals were produced in catalytic ozonation system than those of single ozonation. Intermediates mainly including aliphatic carboxylic acids were determined qualitatively and semi-quantitatively by GC-MS. And, a general pathway for mineralization of DCP was proposed. 相似文献
143.
Leaching behavior of heavy metals from municipal solid waste incineration bottom ash and its geochemical modeling 总被引:1,自引:1,他引:0
Hua Zhang Pin-Jing He Li-Ming Shao Xin-Jie Li 《Journal of Material Cycles and Waste Management》2008,10(1):7-13
With the increase in the number of municipal solid waste incineration (MSWI) plants constructed in China recently, great attention
has been paid to the heavy metal leaching toxicity of MSWI residues. In this study, the effects of various parameters, including
extractant, leaching time, liquid-to-solid ratio, leachate pH, and heavy metal content, on the release properties of Cd, Cr,
Cu, Ni, Pb, and Zn from MSWI bottom ash were investigated. Partial least-squares analysis was employed to highlight the interrelationships
between the factors and response variables. Both experimental research and geochemical modeling using Visual MINTEQ software
were conducted to study the pH-dependent leaching behavior of these metals in fresh and weathered bottom ash, considering
precipitation/dissolution and surface complexation reactions (adsorption by hydrous ferric oxide and amorphous aluminum oxide/hydroxide).
The results showed that leachate pH was the predominant factor influencing heavy metal leachability. The leaching of Cu, Pb,
and Zn was mainly controlled by precipitation/dissolution reactions, whereas surface complexation had some effect on the leaching
of Cr, Cd, and Ni for certain pH ranges. The modeling results aggreed well with the experimental results.
Part of this work was presented at the Fourth International Conference on Combustion, Incineration/Pyrolysis and Emission
Control (i-CIPEC) 相似文献
144.
结合鼓浪屿区实施ISO14001标准,探讨了其意义,实施步骤和特点,可为其它风景名胜区建立环境管理体系所借鉴。 相似文献
145.
The West Nile virus (WNV) may post a significant health risk for mammals, including humans and insects. This study examines the spatial–temporal effects of environmental factors on WNV dissemination with a case study of ten counties in the southern California, where the epidemic was recently most prevalent within the USA. WNV surveillance data were obtained from the California Vectorborne Disease Surveillance System and Centers for Disease Control and Prevention. Remote sensing and Geographic Information Systems (GIS) techniques were combined to derive environmental variables. Principal component analysis was performed to select the most relevant environmental variables. Two ecological zones were identified based on the selected variables. Identification of risk areas for WNV was limited to a zone with 95% mosquitoes surveillance records. Three time windows, the epidemiological weeks?18–26, 27–35, and 36–44 in each year of 2007–2009, were examined in details with risk area mapping. It is found that the southern part of San Joaquin Valley in Kern County and Los Angeles County (especially its southern part) were the most vulnerable locations for WNV outbreak. Main factors contributing to the WNV propagation included summer mean temperature, annual mean deviation from the mean temperature, land surface temperature, elevation, landscape complexity, landscape diversity, and vegetation water content. The result of this study improves understanding of WNV ecology and provides tools for detecting, tracking, and predicting the epidemic. The holistic approach developed for this study, which integrated remotely sensed, GIS-based, and in situ-measured environmental data with landscape metrics, may be applied to studies of other vector-borne diseases. 相似文献
146.
Kong S Lu B Ji Y Zhao X Bai Z Xu Y Liu Y Jiang H 《Journal of environmental monitoring : JEM》2012,14(3):791-803
15 road and 14 soil dust samples were collected from an oilfield city, Dongying, from 11/2009-4/2010 and analyzed by inductively coupled plasma-mass spectroscopy (ICP-MS) for V, Cr, Mn, Co, Ni, Cu, Zn, As, Cd and Pb within PM(2.5), PM(10) and PM(100) fractions synchronously. Metal concentrations, sources and human health risk were studied. Results showed that both soil and road dust exhibited higher values for Mn and Zn and lower values for Co and Cd for the three fractions. Mass concentration ratios of PM(2.5)/PM(10) and PM(10)/PM(100) for metals in road and soil dust indicate that most of the heavy metals tend to concentrate in fine particles. Geoaccumulation index and enrichment factors analysis showed that Cu, Zn and Cd exhibited moderate or heavy contamination and significant enrichment, indicating the influence of anthropogenic sources. Vanadium, Cr, Mn and Co were mostly not enriched and were mainly influenced by crustal sources. For Ni, As and Pb, they ranged from not enriched to moderately enriched and were influenced by both crustal materials and anthropogenic sources. The conclusions were confirmed by multivariate analysis methods. Principle component analysis revealed that the major sources were vehicle emission, industrial activities, coal combustion, agricultural activities and crustal materials. The risk assessment results indicated that metal ingestion appeared to be the main exposure route followed by dermal contact. The most likely cause for cancer and other health risks are both the fine particles of soil and road dusts. 相似文献
147.
148.
有2种不同方法制备的H2S标准溶液进行测定,结果表明,所得标准曲线斜率一致,因此,在实际工作中可对其灵活运用。 相似文献
149.
The main objective of this study was to investigate occurrence of polycyclic aromatic hydrocarbons (PAHs) in the sources of the drinking water supply of Hong Kong. The main emphasis was on the Dongjiang River in mainland China which is the major source, supplying 80% of the total consumption in Hong Kong (the remaining 20% is obtained from rain water). Sediments were collected from four sites along the Dongjiang River and four reservoirs in Hong Kong during both the dry and wet weather seasons. The concentrations of total PAHs in the sediments ranged between 36 and 539 microg/kg dry wt. The lower levels were detected at the upstream site on the Dongjiang River and at the reservoirs in Hong Kong (44-85 microg/kg dry wt), while the mid- and downstream sites on the Dongjiang River were more polluted (588-658 microg/kg dry wt). Examination of the PAH profiles revealed that the mid- and downstream sections of the Dongjiang River contained high percentages of 4,5,6-ring PAHs, similar to the amounts of atmospheric particulate matter and road dust collected during the dry weather season from the Pearl River Delta region as reported in the literature. Seasonal changes were revealed in the reservoirs of Hong Kong, with higher PAH levels in the wet weather season than in the dry weather season. For those reservoirs in Hong Kong that store water from the Dongjiang River, a distinct seasonal pattern was also observed, namely, that under dry weather season conditions the PAHs found in the sediments were primarily from petrogenic source, while under wet weather season conditions they were from pyrolytic sources. No such pattern was detected in the reservoirs which stored only rain water. 相似文献
150.