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991.
D.Y.C. Leung P. Wong B.K.H. Cheung A. Guenther 《Atmospheric environment (Oxford, England : 1994)》2010,44(11):1456-1468
This paper describes a study of local biogenic volatile organic compounds (BVOC) emissions from the Hong Kong Special Administrative Region (HKSAR). An improved land cover and emission factor database was developed to estimate Hong Kong emissions using MEGAN, a BVOC emission model developed by Guenther et al. (2006). Field surveys of plant species composition and laboratory measurements of emission factors were combined with other data to improve existing land cover and emission factor data. The BVOC emissions from Hong Kong were calculated for 12 consecutive years from 1995 to 2006. For the year 2006, the total annual BVOC emissions were determined to be 12,400 metric tons or 9.82 × 109 g C (BVOC carbon). Isoprene emission accounts for 72%, monoterpene emissions account for 8%, and other VOCs emissions account for the remaining 20%. As expected, seasonal variation results in a higher emission in the summer and a lower emission in the winter, with emission predominantly in day time. A high emission of isoprene occurs for regions, such as Lowest Forest-NT North, dominated by broadleaf trees. The spatial variation of total BVOC is similar to the isoprene spatial variation due to its high contribution. The year to year variability in emissions due to weather was small over the twelve-year period (?1.4%, 2006 to 1995 trendline), but an increasing trend in the annual variation due to an increase in forest land cover can be observed (+7%, 2006 to 1995 trendline). The results of this study demonstrate the importance of accurate land cover inputs for biogenic emission models and indicate that land cover change should be considered for these models. 相似文献
992.
Negative effects of noise on individuals, the inevitable result of urbanization, have become a significant urban problem in our day. Introduction of an approach to the noise problem on an urban-planning scale lightens the burden of measures required to be taken against noise at the stages of regional and developmental planning. Stadiums, which should be also evaluated from the point of noise problem when planning decisions are made on the urban planning scale, may cause very serious problems differing depending on the region they are located in. In this article, various dimensions of the noise problem caused by stadiums have been exemplified by making an assessment on Ali Sami Yen football stadium located in Mecidiyeköy district which is among important residential and commercial centres of ?stanbul or Turkey. When the simulation results obtained for ordinary days and match days are evaluated, it has been found out that the people living in the area are exposed to noise levels substantially exceeding the acceptable values. Results of the survey conducted in the area have clearly revealed the existence of noise problem, too. 相似文献
993.
Research on the alternatives in a strategic environmental assessment based on the extension theory 总被引:1,自引:0,他引:1
The main purpose of a strategic environmental assessment (SEA) is to facilitate the early consideration of potential environmental impacts in decision-making processes. SEA alternative identification is a core issue within the SEA framework. However, the current methods of SEA alternative formulation and selection are constrained by the limited setting range and lack of scientific evaluation. Thus, the current paper attempts to provide a new methodology based on the extension theory to identify a range of alternatives and screen the best one. Extension planning is applied to formulate a set of alternatives that satisfy the reasonable interests of the stakeholders. Extension priority evaluation is used to assess and optimize the alternatives and present a scientific methodology for the SEA alternative study. Thereafter, the urban traffic plan of Dalian City is used as an example to demonstrate the feasibility of the new method. The traffic planning scheme and the environmental protection scheme are organically combined based on the extension theory, and the reliability and practicality of this approach are examined. 相似文献
994.
采用竹炭-微生物联合法,考察了竹炭用量、菌液用量、进水氨氮浓度、pH、DO、HRT等因素对氨氮废水处理效果的影响;同时采用对比实验,初步探讨了竹炭-微生物联合法处理沼液的作用机理。结果表明,竹炭-微生物法去除沼液氨氮的最优条件推荐为:竹炭用量30 g/L,微生物活性液用量3%,pH 7.0~8.0,DO为2 mg/L,HRT为48 h。竹炭-微生物法对沼液氨氮的去除过程可用一级反应动力学模型C=272.56e-0.0148描述,其去除效果来源于竹炭吸附和生物降解的协同作用,协同程度为48.45%。 相似文献
995.
聚丙烯酸钠作为调理剂对好氧堆肥的保氮影响 总被引:2,自引:0,他引:2
实验以污泥、锯末、猪粪为原料,以聚丙烯酸钠(PAAS)为调理剂,利用自制好氧堆肥反应器,研究了PAAS在污泥好氧堆肥中的保氮效果。实验显示,PAAS会提高堆体的pH水平,抑制氨氮的生成,从而减少NH3的挥发源,在PAAS对水溶性氨的吸附作用下,堆肥产品的最终氨氮水平依然得到提高;PAAS对硝化反应有一定的促进作用,添加PAAS的堆体在堆肥周期内的硝氮平均增幅可达到未添加PAAS的空白堆体的4.64倍;添加PAAS的堆体在堆肥周期内全氮平均降幅只有空白堆体的52.24%。PAAS做为堆肥调理剂起到了较为明显的保氮效果。 相似文献
996.
997.
水资源短缺已成为限制华北地区社会经济发展的主要因子之一,其中山区来水减少问题已成为该区域水资源研究亟待解决的关键问题。采用景观格局分析法及统计学方法对华北土石山区典型流域--红门川流域土地/覆被变化及其水文动态响应进行分析。结果表明:(1)1990~2005年流域景观呈破碎化趋势,其中,优势景观林地在研究时段内面积变化不大;耕地、建设用地面积增加趋势显著,增幅分别为431%和444%;水域减少趋势最为明显,减幅达208%。(2)土地利用/覆被变化对流域径流有显著调节作用:随着土地结构不断优化,森林、耕地面积的增加,1998~2005年流域平均年径流系数较1990~1998年下降77%;丰、平和枯水年径流系数则分别减少64%、31%和85%;当剔除降水因素后,土地利用景观结构优化使得月径流系数减少16%~100%。(3)土地利用/覆被变化对流域径流的调节作用呈现季节性,植物生长季径流调节尤为显著 相似文献
998.
介质阻挡放电联合催化臭氧化降解甲苯 总被引:4,自引:2,他引:2
采用介质阻挡放电区后结合MnOx/Al2O3/发泡镍去除甲苯,考察甲苯进气方式、臭氧产生方法及湿度对甲苯与O3同时去除的影响。结果表明,O3是等离子体区后催化降解甲苯的主要物种,介质阻挡放电联合催化臭氧化可实现甲苯及O3的同时高效去除。输入电压为9.0 kV时,甲苯的去除效率达92.8%,在80 min内O3的去除效率维持在99%以上。水蒸气对催化剂催化分解臭氧的活性没有直接的影响,O3浓度较高时湿度对甲苯降解效率的影响很小。GC-MS分析结果表明,甲苯降解的主要气相副产物有烷烃、酸、酮和含苯环有机物,提出了甲苯的降解途径。 相似文献
999.
1000.
煤与瓦斯突出影响因素评价分析的模糊层次分析方法 总被引:6,自引:3,他引:3
在综合分析煤与瓦斯突出的影响因素的基础上,采用模糊层次分析法(FAHP)建立了煤与瓦斯突出模糊层次分析模型并进行了实例分析,确定了煤与瓦斯突出各影响因素的权重系数。评价结果表明:地应力、地质构造、瓦斯压力等是影响煤与瓦斯突出的主要因素。为制定相应的煤与瓦斯突出防治措施,提供了科学的理论依据和切合实际情况的评价方法。 相似文献