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1.
The ambient air quality in Central Europe appears to have the potential to adversely affect the productivity of the agroecosystems in that geographic area. Therefore, there is a need to develop, validate, and apply air pollutant exposure-plant response models to explain the relationships between the stochastic chemical climate and ecosystem responses. Such models will have to include numerical terms for the effective air pollutant exposure regime to account for the fluxes of matter, energy and information within the ecosystem and its components. The structure and function of the ecosystem which are influenced by the air pollutant flux can be described by a combination of empirical and mechanistic models. A discussion of such an approach is presented in this paper.  相似文献   

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Today, many more communities in the United States are in a better position to undertake the study of the possible health effects of the air pollution in their environment than has been possible before. Further, such study may furnish baseline data for evaluating the efficacy of air pollution control activity in those cities.

Assessment by city and county control officials can be accomplished by examining the relationship between the demographic characteristics of the area as reported in the 1970 Census of Population, the aerometric measurements now being made routinely in many areas, and mortality in the population as reported to the state office of vital statistics. From the census, detailed demographic or population data will be available by census tract in urban areas. These areas include virtually every U. S. city with a population of 50,000 or more.

The procedures used in the Buffalo and Nashville Air Pollution Studies are discussed with a view toward possible replication by other geographic areas. The need to take account of differences in socio-economic status is emphasized, as is the desirability of obtaining smoking histories. Another major type of air pollution research which is again made possible by the 1970 Census is the comparison of mortality experience, on an agespecific and an age-adjusted basis centered around 1970, for the more than 200 Standard Metropolitan Statistical Areas in the United States.  相似文献   

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对粪产碱杆菌B-20进行发酵培养,观察菌株生长与絮凝剂积累、絮凝性、糖类物质消耗和氧浓度之间的关系,发现菌株的生长与絮凝剂的积累呈正相关,并且发酵培养过程中pH保持在7.2~7.9.通过热诱变获得能够稳定传代的B-2022突变菌株,比较了在不同pH、CaCl2添加量、菌液添加量以及不同温度条件下,其与原菌株B-20的发酵混合液的絮凝率差异,发现热诱变菌株B-2022具有更好的絮凝性能,尤其对pH的适应性较强,最优的絮凝条件为pH=9.0、100 mL高岭土悬浮液中1%(质量分数)CaCl2和发酵混合液添加量都为4 mL.进一步将热诱变菌株B-2022紫外诱变45 s,得到紫外诱变菌株B-2022c,其最佳絮凝率可达94.3%,比原菌株B-20和热诱变菌株B-2022的最佳絮凝率分别提高了2.4%和1.7%.通过化学法、紫外分光光度法和红外分光光度法测得絮凝剂的主要化学成分为糖类物质.  相似文献   

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近年来城市污水处理设施数量不断增加,由此产生的臭气污染严重影响了环境空气质量,并严重损害了城市居民健康。污水脱臭问题引起广泛关注。通过介绍除臭技术在污水处理厂的实际应用,分析了常用除臭技术的优缺点和适用条件,阐述了目前低温等离子体法及纳米材料净化法等除臭新技术的研究现状,同时对除臭技术发展趋势进行展望,为实际工程应用提供指导。  相似文献   

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Li H  Helm PA  Paterson G  Metcalfe CD 《Chemosphere》2011,83(3):271-280
The effect of solution pH and levels of dissolved organic matter (DOM) on the sampling rates for model pharmaceuticals and personal care products (PPCPs) and endocrine disrupting substance (EDS) by polar organic chemical integrative samplers (POCIS) was investigated in laboratory experiments. A commercially available POCIS configuration containing neutral Oasis HLB (hydrophilic-lipophilic balance) resin (i.e. pharmaceutical POCIS) and two POCIS configurations prepared in-house containing MAX and MCX anion and cation exchange resins, respectively were tested for uptake of 21 model PPCPs and EDS, including acidic, phenolic, basic and neutral compounds. Laboratory experiments were conducted with dechlorinated tap water over a pH range of 3, 7 and 9. The effects of DOM were studied using natural water from an oligotrophic lake in Ontario, Canada (i.e. Plastic Lake) spiked with different amounts of DOM (the concentration of dissolved organic carbon ranged from 3 to 5 mg L−1 in uptake experiments). In experiments with the commercial (HLB) POCIS, the MCX-POCIS and the MAX-POCIS, the sampling rates generally increased with pH for basic compounds and declined with pH for acidic compounds. However, the sampling rates were relatively constant across the pH range for phenols with high pKa values (i.e. bisphenol A, estrone, estradiol, triclosan) and for the neutral pharmaceutical, carbamazepine. Thus, uptake was greatest when the amount of the neutral species in solution was maximized relative to the ionized species. Although the solution pH affected the uptake of some model ionic compounds, the effect was by less than a factor of 3. There was no significant effect of DOM on sampling rates from Plastic Lake. However, uptake rates in different aqueous matrixes declined in the order of deionized water > Plastic Lake water > dechlorinated tap water, so other parameters must affect uptake into POCIS, although this influence will be minor. MAX-POCIS and MCX-POCIS showed little advantage over the commercial POCIS configuration for monitoring in natural waters.  相似文献   

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Successful river basin governance is challenged by actor engagement in the various stages of planning and management. A governance approach for determining priorities for actors for sustainable management was developed, based on a river basin diagnostic framework consisting of four social-institutional and four biophysical indicators. It was applied in river basins in Australia, Brazil, China and France. Actors diagnosed current and target capacity for these indicators, and estimated synergistic influences of interacting indicators. The results reveal different priorities and transformative pathways to achieve basin plan outcomes, specific to each basin and actor groups. Priorities include biodiversity for the Murray-Darling, local water management needs for the São Francisco and Yellow rivers, and improved decision-making for the Adour-Garonne. This novel approach challenges entrenched views about key issues and actor engagement roles in co-implementation of the basin plan under existing prevailing governance models, with implications for engagement and international collaboration on basin governance.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01699-4.  相似文献   

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基于一级水解模型推导出含有单位可挥发性有机物理论沼气产量(ym,mg/L)与水解常数(k,d-1)组合项的动力学模型,将其应用于餐厨垃圾及其组分在厌氧消化过程中产沼气的特性规律分析,为研究厌氧消化机制提供理论基础。结果表明,除了脂肪厌氧消化拟合的R2为0.899 0,其余的均大于0.9,其中餐厨垃圾的R2为0.992 5,淀粉的R2为0.972 4。说明该模型能很好地反映厌氧消化的实际效果。厌氧消化水解速率依次为淀粉餐厨垃圾纤维素蛋白质脂肪。淀粉、餐厨垃圾、纤维素的k分别为0.198 3、0.089 7、0.013 9d-1,蛋白质、脂肪的k都小于零。单组分中淀粉lnym+lnk为4.983 6,表现出最好的产沼气特性;其次是蛋白质和纤维素,其值分别为2.157 8、2.046 6;脂肪产沼气特性最差,其值仅为0.902 4,与淀粉相比降低了81.89%;餐厨垃圾lnym+lnk为4.329 6,是淀粉的86.88%,产气特性仅次于淀粉。  相似文献   

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As an integral part of our continuing research in environmental quality assessment approaches, we have developed a variety of passive integrative sampling devices widely applicable for use in defining the presence and potential impacts of a broad array of contaminants. The semipermeable membrane device has gained widespread use for sampling hydrophobic chemicals from water and air, the polar organic chemical integrative sampler is applicable for sequestering waterborne hydrophilic organic chemicals, the stabilized liquid membrane device is used to integratively sample waterborne ionic metals, and the passive integrative mercury sampler is applicable for sampling vapor phase or dissolved neutral mercury species. This suite of integrative samplers forms the basis for a new passive sampling approach for assessing the presence and potential toxicological significance of a broad spectrum of environmental contaminants. In a proof-of-concept study, three of our four passive integrative samplers were used to assess the presence of a wide variety of contaminants in the waters of a constructed wetland, and to determine the effectiveness of the constructed wetland in removing contaminants. The wetland is used for final polishing of secondary-treatment municipal wastewater and the effluent is used as a source of water for a state wildlife area. Numerous contaminants, including organochlorine pesticides, polycyclic aromatic hydrocarbons, organophosphate pesticides, and pharmaceutical chemicals (e.g., ibuprofen, oxindole, etc.) were detected in the wastewater. Herein we summarize the results of the analysis of the field-deployed samplers and demonstrate the utility of this holistic approach.  相似文献   

10.
三氯生在水环境中的存在行为及迁移转化规律研究进展   总被引:5,自引:0,他引:5  
近年来,国内外开始关注药品与个人护理品(PPCPs)对环境的污染.三氯生(TCS)作为药品与个人护理品的杀菌、防腐剂在环境中普遍存在.详细介绍了三氯生的基本性质及其在水环境中的赋存现状,并初步比较了污水处理工艺对三氯生的去除效果.  相似文献   

11.
膜生物反应器(MBR)具有与传统工艺无法比拟的优势而成为污水处理中很有前景的工艺。由于MBR工艺本身固有的复杂性和不确定性,发展一种能够为该工艺提供整体性理解的模型是相当必要的。模型的建立可为MBR污水处理的优化设计和运行控制提供理论依据。给出了3类用于模拟MBR工艺的模型:生物动力学模型、膜污染模型和对MBR完整描述的综合模型。在此基础上,阐述了每个模型各自的机制和功能,分析讨论了模型研究与应用中存在的问题,并提出了MBR相关模型的发展前景。  相似文献   

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Membrane-enclosed sorptive coating (MESCO) is a miniaturised monitoring device that enables integrative passive sampling of persistent, hydrophobic organic pollutants in water. The system combines the passive sampling with solventless preconcentration of organic pollutants from water and subsequent desorption of analytes on-line into a chromatographic system. Exchange kinetics of chemicals between water and MESCO was studied at different flow rates of water, in order to characterize the effect of variable environmental conditions on the sampler performance, and to identify a method for in situ correction of the laboratory-derived calibration data. It was found that the desorption of chemicals from MESCO into water is isotropic to the absorption of the analytes onto the sampler under the same exposure conditions. This allows for the in situ calibration of the uptake of pollutants using elimination kinetics of performance reference compounds and more accurate estimates of target analyte concentrations. A field study was conducted to test the sampler performance alongside spot sampling. A good agreement of contaminant patterns and water concentrations was obtained by the two sampling techniques.  相似文献   

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水环境中双酚A的污染及其生态毒理效应   总被引:3,自引:0,他引:3  
双酚A(BPA)广泛存在于水环境中,是一种雌激素,对人类健康和生态系统安全造成潜在威胁.BPA在各种水体中都有检出,且检出浓度有逐年增大的趋势;BPA在垃圾渗滤液、污水处理厂的出水及其污泥和沉积物中都能检出,且其浓度一般较地表水中的浓度大.在综述了BPA在环境中的污染现状、迁移转化行为和生态毒理效应的研究进展基础上,指出了进一步研究BPA的重要性和今后的研究方向.  相似文献   

16.
ZSM-5沸石的制备及其对甲基叔丁基醚的吸附性能研究   总被引:1,自引:0,他引:1  
采用无模板剂水热合成法和晶种诱导水热合成法成功制备了ZSM-5沸石.使用X射线衍射(XRD)、扫描电子显微镜(SEM)和BET比表面积测试等手段对合成产物进行了表征,结果显示,两种ZSM-5沸石晶体粒径均在微米级,孔道均以0.60~1.00nm的微孔为主,晶种诱导合成ZSM-5沸石微孔体积更大.采用气相色谱法分析了ZSM-5沸石对甲基叔丁基醚(MTBE)的吸附性能.结果表明,晶种诱导合成的ZSM-5沸石对MTBE的吸附容量较无模板剂合成ZSM-5沸石高,原因是两种ZSM-5沸石孔道分布有差异.研究还显示,晶种诱导合成ZSM-5沸石对MTBE的吸附容量随其投加量的增大而减小,存在明显的固体浓度效应;吸附体系达吸附平衡较慢,说明MTBE在ZSM-5沸石微孔道的扩散是影响吸附平衡的控制因素;该沸石再生方便,对处理初始质量浓度为200~1000μg/L的MTBE溶液具有较好的再生吸附性能.  相似文献   

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反硝化碳源在人工湿地脱氮中的应用及其研究进展   总被引:1,自引:0,他引:1  
碳源供给是制约人工湿地反硝化脱氮的重要因素,系统论述了反硝化碳源的类型及其在人工湿地反硝化过程中的作用,并对人工湿地中反硝化碳源的应用现状进行了讨论.反硝化菌与人工湿地脱氮有着密切关联,是人工湿地领域研究的焦点.此外,人工湿地中的环境条件、运行条件及湿地构建条件等都会对其反硝化效果产生重要影响,指出了通过改善上述条件提...  相似文献   

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The Varroa mite (Varroa destructor) is implicated as a major disease factor in honey bee (Apis mellifera) populations worldwide. Honey bees are extensively relied upon for pollination services, and in countries such as New Zealand and Australia where honey bees have been introduced specifically for commercial pollinator services, the economic effects of any decline in honey bee numbers are predicted to be profound. V. destructor established in New Zealand in 2000 but as yet, Australia remains Varroa-free. Here we analyze the history of V. destructor invasion and spread in New Zealand and discuss the likely long-term impacts. When the mite was discovered in New Zealand, it was considered too well established for eradication to be feasible. Despite control efforts, V. destructor has since spread throughout the country. Today, assessing the impacts of the arrival of V. destructor in this country is compromised by a paucity of data on pollinator communities as they existed prior to invasion. Australia’s Varroa-free status provides a rare and likely brief window of opportunity for the global bee research community to gain understanding of honey bee-native pollinator community dynamics prior to Varroa invasion.  相似文献   

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发展"资源-产品-废弃物-再生资源"反馈式循环的农业循环经济是变革传统的生产方式、生活方式,解决现代农业困境,实现整个社会大循环的必然选择.概述了中国农业循环经济立法的不足和成因,并提出了以循环经济为理念"绿化"现行农业法律、法规,制定专门的农业循环经济法律、法规以及修改<环境保护法>等对策.  相似文献   

20.

Data reconciliation and mass balance analysis were conducted for the first time to improve the data obtained from a petrochemical wastewater treatment plant (WWTP), and the results were applied to evaluate the performance of the plant. Daily average values for 209 days from the inlet and outlet of the plant obtained from WWTP documentation center along with the results of four sampling runs in this work were used for data reconciliation and performance evaluation of the plant. Results showed that standard deviation and relative errors in the balanced data of each measurement decreased, especially for the process wastewater from 24.5 to 8.6 % for flow and 24.5 to 1.5 % for chemical oxygen demand (COD). The errors of measured data were −137 m3/day (−4.41 %) and 281 kg/day (7.92 %) for flow and COD, respectively. According to the balanced data, the removal rates of COD and 5-day biological oxygen demand (BOD5) through the aeration unit were equal to 37 and 46 %, respectively. In addition, the COD and BOD5 concentrations were reduced by about 61.9 % (2137 kg/day) and 78.1 % (1976 kg/day), respectively, prior to the biological process. At the same time, the removal rates of benzene, toluene, and styrene were 56, 38, and 69 %, respectively. The results revealed that about 40 % of influent benzene (75.5 kg/day) is emitted to the ambient air at the overhead of the equalization basin. It can be concluded that the volatilization of organic compounds is the basic mechanism for the removal of volatile organic compounds (VOCs) and it corresponds to the main part of total COD removal from the WWTP.

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