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1.
During very considerable progress in industry and industrial centres development in late 20th and early 21st century, air pollution has become one of the most significant problems of mega cities. Thus, air pollution survey to exert abatement methods has a very important role. Various methods are available for air pollution monitoring which are very costly. Air pollution monitoring by susceptible plants as biological indicators are not only economic but also simple. In this paper, vast studies were done on the plants of around each Queensland Environmental Protection Agency (QEPA) monitoring sites. Around these sites susceptible plants to air pollution were neither available nor exist in all monitoring sites. Therefore, it seemed the best method is the portable exposure benches application with automatic watering system in five sites among all studied locations. In this research different varieties of tobacco like Weather fleck, Bel-B, Bel-W3, Dynes, ZZ100 were used to measure the impact of ozone as a pollutant on them. Parsley cv. Frizz and Leek cv. Vertina were selected as nitogen oxides indicators. In general, the above-mentioned plants were exposed to the ambient air in five sites around Brisbane from April 1997 to May 1998. The susceptible variety leaves of Bel-W3 showed injuries just in two sites. The reason for this is the high level of ozone and the effects of climatic factors in production and dispersion of it during the experiments. The survey results represent that ozone with elevated concentrations is available as far as 30km radius from Brisbane city centre. Within this area only the most susceptible plants’ leaves would be liable to suffer injury.  相似文献   

2.
根细胞壁是植物吸收、转运镉(Cd)的第一道屏障。为了揭示烟草根细胞壁中Cd的亚细胞分布与结合形态对烟草茎叶Cd吸收、转运的影响机理,文中研究了12种不同烟草根、茎、叶对Cd的富集、转运特征,利用活体细胞分离技术分析了根细胞壁中Cd的亚细胞分布及结合形态,在此基础上对根细胞壁Cd的亚细胞分布与烟草Cd吸收、转运的关系进行了研究。结果表明不同烟草根、叶对土壤中Cd的富集系数间存在显著差异(P<0.05)：根中Cd含量为3.13~7.10 mg/kg,最大相差2.27倍;烟叶中Cd含量为3.29~9.93 mg/kg,最大相差3.0倍;根叶转运系数为0.50~3.17,最大相差6.34倍。烟草根部Cd主要以醋酸浸提态(FHAC)为主。不同细胞壁组分中Cd含量测定发现,去果胶后细胞壁(CW-P)中Cd含量显著增加,而去半纤维素后细胞壁中Cd含量显著降低。去果胶后细胞壁中Cd含量与根叶中Cd的转运系数呈显著的负相关,转运系数最低的K346中,CW-P中Cd含量最高,说明半纤维素是烟草根细胞壁蓄积Cd的主要场所,烟草根细胞壁中半纤维素对Cd的束缚降低了Cd通过长距离向地上部分的转运。  相似文献   

3.
《Comptes Rendus Geoscience》2018,350(7):354-367
In the 1980s, ground-based monitoring of the ozone layer played a key role in the discovery of the Antarctic Ozone Hole as well as in the first documentation of significant winter and spring long-term downward trends in the populated mid-latitude regions. The article summarizes the close-to-hundred-year-long history of ground-based measurements of stratospheric ozone, and more recent observations of constituents that influence its equilibrium. Ozone observations began long before the recognition of the impact of increasing emissions of manmade ozone-depleting substances on ozone and therefore on UV levels, human health, ecosystems and the Earth climate. The historical ozone observations prior to 1980s are used as a reference for the assessments of the state of the ozone layer linked to the enforcement of the Montreal Protocol. In this paper, we describe the worldwide monitoring networks and their ozone observations used to determine long-term trends with an accuracy of a few percent per decade. Since 1989, the ground-based monitoring activities have provided support for the amendments of the Montreal Protocol (MP). They include monitoring of (a) the ozone total column and the vertical distribution at global scale, (b) the ozone-depleting substances (ODS) related to the MP such as chlorofluorocarbons (CFCs), and their decomposition products in the stratosphere, and (c) the atmospheric species playing a role in ozone depletion, e.g., nitrogen oxides, water vapor, aerosols, polar stratospheric clouds. We highlight important accomplishments in the atmospheric monitoring performed by the Global Atmosphere Watch program (GAW) run under the auspices of the World Meteorological Organization (WMO) and by the Network for the Detection of Atmospheric Composition Change (NDACC). We also address the complementary roles of ground-based networks and satellite instruments. High-quality ground-based measurements have been used to evaluate ozone variabilities and long-term trends, assess chemistry climate models, and check the long-term stability of satellite data, including more recently the merged satellite time-series developed for the detection of ozone recovery at global scale, which might be further modified by climate change.  相似文献   

4.
为研究不同微生物肥对土壤中Cd的钝化效果和烟叶Cd含量的影响,选取南方植烟区3种不同类型(红泥田、黄泥田及青紫泥田)Cd污染土壤,以南方主栽烤烟云-87和K-326为测试品种,采用盆栽试验,测定了3种微生物肥(DY、AMS和HMD)在不同浓度下对烟草生物量、不同部位烟叶Cd含量、土壤Cd形态以及土壤中微生物种类的影响。结果表明：(1)3种微生物肥均能增加烟叶生物量,其中HMD增重效果最好。(2)与对照相比,3种微生物肥能有效地降低土壤中Cd的有效性和烟叶Cd的含量。针对3种土壤施用微生物肥浓度为1.5%时,叶片中Cd的降Cd率(与对照相比)分别达到17.2%~63.9%、20.4%~58.3%及18.9%~48.3%,DTPA-Cd下降比例分别为13.8%~17.3%、17.2%~22.8%及12.8%~16.2%;而随着施用微生物肥浓度增加到3.0%后,上述土壤烟叶中Cd的降Cd率显著增加,分别为20.3%~59%、31.3%~66.6%及25.2%~56.1%,DTPA-Cd下降比例分别为15.5%~28.2%、19.6%~26.6%及13.8%~17.3%。HMD效果最好,其次为DY和AMS。(3)3种微生物肥都增加土壤中微生物种类和数量,优化了烟草生长环境。总体来说,该植烟区土壤,DY和HMD增加产量的同时降Cd效果较好,可以在大田推广使用。  相似文献   

5.
It is known that hydrogen peroxide interferes with chemical oxygen demand analysis by consuming oxidation agents such as potassium dichromate, thus leading to overestimation of the chemical oxygen demand measurements. The objective of the study was to investigate the effects of hydrogen peroxide interference and to determine true chemical oxygen demand values on interpreting treatment performance during ozone-based advanced oxidation of livestock wastewater in which hydrogen peroxide concentration and chemical oxygen demand values are dynamically changing. According to the chemical oxygen demand monitoring data, chemical oxygen demand values were always higher than the initial chemical oxygen demand load when hydrogen peroxide was involved and the treatment performance with ozone alone or ozone/ultraviolet was better than with coupled hydrogen peroxide. The extent of overestimation was proportional to the remaining hydrogen peroxide concentration and the average overestimation ratio in livestock wastewater was in the range of 0.50～0.58 mg per 1 mg of hydrogen peroxide, depending upon the quality of the wastewater treated. True chemical oxygen demand values were estimated by correlating the extent of overestimation with the remaining hydrogen peroxide concentration during treatment. The extent of overestimation decreased to zero gradually as the amount of hydrogen peroxide also approached zero as oxidation proceeded. The corrected chemical oxygen demand values indicated underlying tendency of oxidation, which could not be seen in the original chemical oxygen demand monitoring data. Application of ozone/hydrogen peroxide was more efficient for reducing chemical oxygen demand than ozone alone, as was ozone/hydrogen peroxide/ultraviolet compared to ozone/ultraviolet. When coupled with ozone, ultraviolet irradiation was more efficient than hydrogen peroxide for decreasing chemical oxygen demand during treatment of livestock wastewater.  相似文献   

6.
为研究不同农艺措施对烟叶镉(Cd)富集及生长发育的影响,选取中国南方植烟区两种Cd污染土壤(红泥田、黄泥田)为研究对象,以云烟87为供试品种,通过田间小区试验,研究增施磷酸二氢钾、硫酸锌、腐殖酸络合钾和生石灰对土壤Cd有效态含量、烟叶Cd含量、土壤肥力指标、烤烟经济性状及常规化学成分的影响。结果表明：与对照组相比,增施磷酸二氢钾、硫酸锌、腐殖酸络合钾和生石灰均能有效减少土壤Cd生物有效性和烟草对Cd的富集,土壤有效态Cd含量降低10.4%~25.5%,烟叶Cd消减率为20.39%~43.47%,不同处理顺序为磷酸二氢钾>腐殖酸络合钾>硫酸锌≈生石灰;施用生石灰可提高土壤pH值0.24~0.51,但会造成土壤肥力下降,影响烤烟生长发育;增施腐殖酸络合钾可提高土壤脲酶和磷酸酶活性,提高土壤有机质含量、阳离子交换量、有效氮含量等肥力指标,显著提高烤后烟叶钾含量,降低烟叶糖含量,使烟叶化学成分更趋于协调。  相似文献   

7.
Wheat cultivars of diverse origin including approved varieties of different provinces of Pakistan i.e. Punjab, NWFP and Sindh were tested against different salinity levels in laboratory as well as in naturally saline fields in different ecological zones. Initially, 16 genotypes were studied for germination test at 6 different salinity levels ranging from 0–25 dS/m (2, 5, 10, 15, 20, 25, EC= dS/m). Then, out of 16 cultivars, 11 were studied for the relative growth rate at different levels of salinity and after their study in the laboratory, 9 genotypes were selected for testing in the naturally saline areas of Punjab province. Under germination percentage study, the varieties viz. Pasban-90, Sarsabz, Bakhtawar, 93032 and 933118 were less affected than other varieties. As regards the relative plant growth, varieties viz. Sarsabz, Bakhtawar, and Pasban-90 were tolerant to salinity at seedling stage while Inqlab was graded as sensitive to salt stress. Regarding field performance, significant differences were observed in the varieties grown under different saline environments and varieties x environment interaction. Varieties x environment (Lin) interaction was non significant while nonlinear interaction (pooled deviation) was significant. Based on overall yield performance, the Sarsabz variety produced the highest seed yield (4.37 T/ha) followed by Bakhtawar (4.24 T/ha) and Pasban-90 (3.93 T/ha). Regression coefficient values showed non significant differences to unity while standard deviation to regression showed significant differences to zero. These results indicated that the genotypes viz. Sarsabaz, Bakhtawar and Pasban-90 are better tolerant to saline environment as compared to others. The two genotypes, Marvi and 25219 had low regression values and can fit under stress environment.  相似文献   

8.
K. Küppers  G. Klumpp 《GeoJournal》1988,17(2):271-275
Spruce clones were fumigated in greenhouses with ozone and sulfur dioxide singly and in combination for two growing seasons. At the end of the 15 months' experiment one-year-old needles showed decreased photosynthesis (70% of control) after single treatment with O3 and SO2, respectively, the combination O3/SO2 enhanced the effect (50% of control). Photosynthesis of current year needles was hardly influenced by fumigation, whereas respiration was stimulated especially by O3 alone and in combination with SO2. Exposure to O3 and O3/SO2 caused starch accumulation in one-year-old needles up to 200%, while levels of current year needles were nearly unaffected. Roots exhibited lowered starch contents in all the three fumigation treatments. A climatic chamber experiment with various combinations of O3, SO2, and NO2 revealed after 6 months reduction of photosynthesis, the three-component-application being most effective followed by O3/NO2. SO2/NO2 had little effect. The light compensation point was raised after fumigation with O3/NO2 and O3/SO2/NO2.  相似文献   

9.
《Atmósfera》2014,27(3):261-271
Air pollution is the main environmental issue in Mexico City, where ozone is one of the most damaging pollutants for human health. In this work we present a retrospective health impact assessment (HIA) study split up by age groups for evaluating the benefits of ozone regulatory strategies from 1991 to 2011 in Mexico City. Since people move from one place to another during the day, which may affect their potential exposure to pollutants, we consider time-dependant spatial population distributions during the day. Ozone data is made up of observations taken with hourly frequency from January 1, 1991 to December 31, 2011, at approximately 22 stations of the monitoring network of Mexico City. Interpolated values for unknown locations are also taken into account in the HIA. The Cressman objective analysis method is applied for interpolating the observed ozone concentrations from monitoring stations to grids of convenient resolution. We demonstrate that different age groups present different spatial patterns of exposure, being the working-age people (between 18 and 64 years) the most benefited. We also confirm the hypothesis that, in general, people move to less polluted regions during the day.  相似文献   

10.
Widespread detection of pharmaceutical compounds in water environment has been a serious concern recently, while conventional sewage treatments are ineffective for their elimination. But, advanced oxidation techniques are very promising to remove varieties of organic contaminants in water. This research aims to elucidate oxidation potentials of sixteen commonly used pharmaceutical compounds in mixed solutions by seven advanced oxidation techniques in laboratory batch experiments. The removal profiles exhibited four distinct patterns: a) easily degradable by all seven techniques, b) not easily degradable by all seven techniques, c) easily degradable by ozone-based techniques, but not by ultraviolet radiation-based techniques and d) easily degradable by ultraviolet radiation-based techniques, but not by ozone-based techniques. Ozone-based techniques rather than ultraviolet radiation-based techniques were very powerful for simultaneous removal of the compounds efficiently. Moreover, ozonation combined with ultraviolet radiation was the most appropriate technique for simultaneous removal of the tested compounds efficiently. Increased ozone dissolution and decomposition with ozone-based techniques did not always enhance the compounds’ removal. Physicochemical properties of the compounds and solution pH also presumably played an important role on the removal which merits further attention.  相似文献   

11.
《Atmósfera》2014,27(4):377-384
Clean air is a basic requirement for human health and wellbeing. The Kenya Meteorological Department has established air pollution monitoring activities in various sites in Nairobi, at Dagoretti Corner meteorological station and at Mount Kenya. Different pollutants are measured including ozone. The increased concentration of greenhouse gases in the atmosphere has influenced the weather and climate. This study examined the variations of surface ozone over Dagoretti Corner, Nairobi for a 12-month period ending July 2013, exactly one year after the start of data acquisition. The trend was studied using time series analysis of ozone concentration on both an hourly and monthly basis. The ozone data was then combined with meteorological data and temperature to find correlations between the two. Overall, the air quality of Nairobi, represented by Dagoretti Corner meteorological station is good as compared to the World Meteorological Organization ozone standards. The highest concentration of ozone is observed in the afternoon and the minimum at dawn on a daily basis. On seasonal scale, the highest levels are recorded in the cold months. This information helps to reduce exposure to the gas and thus to reduce its impacts on living things. The study recommends the reduction of exposure to the gas during the times when it has been observed to be highest in order to minimize its impacts.  相似文献   

12.
中国大气臭氧探空仪的研制和应用   总被引：9，自引：1，他引：9  
地球大气中的臭氧一直是全球气候和环境变化研究中的重要内容。大气臭氧探空系统是当前直接获得地球大气臭氧垂直结构资料的直接探测系统，同时也是为卫星臭氧探测和激光雷达臭氧探测等提供对比和定标的有力手段。中国大气臭氧探空仪的研制工作起步较晚且进展缓慢，这在一定程度上妨碍了中国大气臭氧高空探测业务化的进程。首次报道了中国大气臭氧高空探测业务化进展状况，重点报告中国自行研制的大气臭氧探空仪的结构和技术性能指标，讨论了中国大气臭氧探空仪主要技术性能指标与芬兰Vaisala臭氧探空仪的比对结果，并给出该系统在北京、南极等地区应用施放中所得到的部分探测结果。同时对中国大气臭氧高空探测业务化方面的近期任务提出了建议。  相似文献   

13.
《Comptes Rendus Geoscience》2018,350(7):347-353
After the well-reported record loss of Arctic stratospheric ozone of up to 38% in the winter 2010–2011, further large depletion of 27% occurred in the winter 2015–2016. Record low winter polar vortex temperatures, below the threshold for ice polar stratospheric cloud (PSC) formation, persisted for one month in January 2016. This is the first observation of such an event and resulted in unprecedented dehydration/denitrification of the polar vortex. Although chemistry–climate models (CCMs) generally predict further cooling of the lower stratosphere with the increasing atmospheric concentrations of greenhouse gases (GHGs), significant differences are found between model results indicating relatively large uncertainties in the predictions. The link between stratospheric temperature and ozone loss is well understood and the observed relationship is well captured by chemical transport models (CTMs). However, the strong dynamical variability in the Arctic means that large ozone depletion events like those of 2010–2011 and 2015–2016 may still occur until the concentrations of ozone-depleting substances return to their 1960 values. It is thus likely that the stratospheric ozone recovery, currently anticipated for the mid-2030s, might be significantly delayed. Most important in order to predict the future evolution of Arctic ozone and to reduce the uncertainty of the timing for its recovery is to ensure continuation of high-quality ground-based and satellite ozone observations with special focus on monitoring the annual ozone loss during the Arctic winter.  相似文献   

14.
Twenty-six cowpea cultivars were tested for yellow mosaic virus resistance at NIAB Faisalabad. NCPM-1, Elite, IT-84-552, No.44, P-518, S.A. Dandy, IT-97k-350-4, IT-93K-452, IT-97K-1042-8 and IT-97K-497-2 showed resistant reaction to yellow mosaic virus disease. As the study was aimed to select disease resistant and high yielding cultivars. Five cultivars viz. NCPM-1, Elite. S.A. Dandy, IT-97K-497-2 and IT-97K-1042-8 were chosen and evaluated at five different ecological zones during the year 2003. At each location, the experiment was laid out in a randomized complete block design keeping 7.2 m2 plot size in three repeats. At maturity the seed yield was collected and subjected to analysis of variance following stability parameters, varieties, environment and varieties x environment showed significant differences. Significant and highest seed yield (880 kg/ha) was observed in NIAB cowpea mutant-1 followed by Elite (729 Kg/ha). The highest yielding genotypes i.e. NIAB cowpea Mutant-1 and Elite showed non-significant differences of regression coefficient from one. Moreover these genotypes also exhibited non-significant difference of standard deviation to regression from zero. Based on three parameters i.e. high mean seed yield, regression coefficient and standard deviation to regression, these genotypes showed excellent and trustworthy stable performance over different environment. Hopefully these genotypes will definitely be helpful for increasing one local production of cowpea crop.  相似文献   

15.
催化臭氧化降解有机废水及影响因素   总被引：2，自引：0，他引：2  
主要论述了自制的V-O型催化荆催化臭氧化降解有机废水的研究。试验表明，以TiO2，SiO2，ZrO2作栽体，在氮气或氧气中焙烧，而制得的6种催化荆中，V-O／SiO2／N2显示了较好的催化性能和活性；通过催化荆吸附试验和在反应体系中加入一定量的自由基猝灭荆，初步探讨了其催化机理，即催化荆和臭氧反应，生成了氧化性极强的羟基自由基；催化臭氧化时间、催化荆用量、进气臭氧浓度、体系pH值等因素均对降解产生一定的影响。  相似文献   

16.
Data assimilation plays an important role in the analysis of atmospheric data, in particular for numerical weather prediction and the detection of climate variations. In the field of atmospheric chemistry, assimilation techniques have been recently developed to study the distribution of tracer species, with emphasis on the ozone content. The present work reports on assimilation experiments of vertical ozone profiles from the GOME instrument performed with MOCAGE, a chemical-transport model and a 3D-FGAT variational technique. It is shown that this technique is very well adapted for ozone assimilation and can be extended to various sensors or other trace species. To cite this article: S. Massart et al., C. R. Geoscience 337 (2005).  相似文献   

17.
美国全球变化研究计划实施进展与研究展望   总被引：1，自引：2，他引：1  
美国全球变化研究计划（USGCRP）自成立以来的10年中，取得了丰硕的研究成果，也面临新的挑战，列举了自1990年以来尤其是近几年来USGCRP的主要成果与贡献，其中在国家评估，厄尔尼诺－南方涛动的预测，全球温度记录，过去1000年中最温暖的时期，北美碳汇，温室气体增加与臭氧损耗，臭氧损耗评估，大气污染物的长距离输送，海洋分析，热带测雨卫星，雷达卫星，火灾监测，SeaWiFS，全球环境维息服务等方面取得的成绩尤为显著，剖析了USGCRP在未来10年中的研究目标及其研究重点和面临的挑战。  相似文献   

18.
We tested the accuracy of the chloroform fumigation–extraction method, which is commonly used to determine soil biomass C concentrations. Accurate and precise determination of total microbial biomass is important in order to characterize soil properties and to develop predictive metal transport models for soils. Two natural soils, and individual soil components, including silica sand, montmorillonite, kaolinite, a humic acid, and Bacillus subtilis bacterial cells, were fumigated for 24 h. Following the fumigation, C from fumigated and unfumigated samples was extracted using a 0.5 M K2SO4 solution. The difference between the C content in the fumigated and unfumigated samples ideally represents C due to biomass because the fumigation procedure should lyse cells and release biomass C. We observed increased C release upon fumigation for bacteria-only samples, confirming the ability of fumigation to lyse cells. There was no difference in extracted C concentration between fumigated and unfumigated samples of silica sand and of humic acid, confirming that the fumigation process does not introduce additional organic C to samples of these soil components. However, the fumigated clay samples both showed increased C release relative to the unfumigated controls, indicating that significant concentrations of the fumigant, chloroform, adsorbed onto the clay minerals studied here. Additionally, we found significant chloroform remaining in the extracts from two fumigated natural soils. Attempts to remove the chloroform from the soils or soil components prior to extraction by increasing the evacuation time, or to remove chloroform in the extracts by sparging them vigorously with nitrogen gas, both failed. This research reveals that chloroform gas may adsorb significantly to clays and the clay fraction of natural soils. Thus, the fumigation–extraction method must be corrected to account for the added chloroform C and accurately assess the concentration of biomass C in soils that contain significant concentrations of clays.  相似文献   

19.
对某省5个产地21种烟叶样品用微波密闭消解,电感耦合等离子体直角加速时间飞行质谱(ICP-oaTOF-MS)测定砷、镉、汞、铅的含量。对称样量、微波消解及质谱检测参数、同位素及内标、方法准确性及可行性进行了研究,确定了最佳的实验条件。标准曲线的相关系数>0.9998,方法回收率为91.49%～106.25%,精密度(RSD)<2%,检出限为0.093～0.168μg/L。对在同一品种、同一部位、不同地区的烟叶样品进行测定,结果显示各地区样品中被测元素的含量存在较大差异,As为0.503～1.737 mg/kg,Pb为1.826～4.969 mg/kg,Cd为0.656～2.641 mg/kg,Hg为0.042～0.584 mg/kg;As、Hg含量差异较小,Pb、Cd含量差异较大。相比于其他分析方法,ICP-oaTOF-MS适合对浓度低至ng/L级超痕量组分的分析,具有简便快速、准确、灵敏度高、检出限低等优点,可用于烟叶重金属的检测及质量控制,对于判断烟株的丰缺情况、鉴别烟叶制品的品质具有一定的意义。  相似文献   

20.
衡山岩体西缘韧性剪切带磁性组构研究   总被引：1，自引：1，他引：1  
张志强 《湖南地质》1989,8(2):23-27
本文对采自衡山花岗岩体西缘韧性剪切带的标本进行了岩石磁性组构研究,并将其与常规应变分析方法所得结果予以比较,表明了岩石磁化率各向异性椭球体与应变椭球体之间有一定的对应关系,岩石磁化率各向异性技术可望成为构造地质学的一种新手段。岩石磁性组构资料可应用于变形岩石的应变分析,特别是在没有宏观应变标志或者通常的岩石组构分析方法太费时间的情况下更显出其优越性。  相似文献   

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