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551.
The pollution levels, composition characteristics and sources of atmospheric PM2.5 were investigated based on field measurement at a rural site in the North China Plain (NCP) from pre-heating period to heating period in winter of 2017. The hourly average concentrations of PM2.5 frequently exceeded 150 µg/m3 and even achieved 400 µg/m3, indicating that the PM2.5 pollution was still very serious despite the implementation of stricter control measures in the rural area. Compared with the pre-heating period, the mean concentrations of organic carbon (OC), element carbon (EC) and chlorine ion (Cl?) during the heating period increased by 20.8%, 36.6% and 38.8%, accompanying with increments of their proportions in PM2.5 from 37.5%, 9.8% and 5.5% to 42.9%, 12.7% and 7.2%, respectively. The significant increase of both their concentrations and proportions during the heating period was mainly ascribed to the residential coal combustion. The proportions of sulfate, nitrate and ammonium respectively increased from 9.9%, 10.9% and 9.0% in nighttime to 13.8%, 16.2% and 11.1% in daytime, implying that the daytime photochemical reactions made remarkable contributions to the secondary inorganic aerosols. The simulation results from WRF-Chem revealed that the emission of residential coal combustion in the rural area was underestimated by the current emission inventory. Six sources identified by positive matrix factorization (PMF) based on the measurement were residential coal combustion, secondary formation of inorganic aerosols, biomass burning, vehicle emission and raising dust, contributing to atmospheric PM2.5 of 40.5%, 21.2%, 16.4%, 10.8%, 8.6% and 2.5%, respectively.  相似文献   
552.
雄安新区土壤重金属地球化学监测关键问题探讨   总被引:6,自引:5,他引:1  
为构建雄安新区土壤环境质量监控网,系统获取雄安新区建设前后土壤重金属地球化学数据,长期监测新区建设过程中土壤重金属的变化趋势,在分析雄安新区土地质量地球化学调查监测数据和土壤重金属元素地球化学空间变异特征的基础上,采用统计学方法估算构建新区土壤地球化学监测网所需要的采样密度、采样数量和采样周期等参数,为后续新区土壤重金属地球化学长期监测工作提供参考.结果表明,调查区重金属As、 Cd、 Cu、 Hg和Pb元素变异系数36%,属于高度变异元素; Cd、 Cu和Pb元素块金系数均75%,其高度富集是在较高自然背景上出现了人为源的叠加.在置信水平P为95%和90%时,对样本平均值允许误差Δ分别为5%、 10%和15%的条件下,同时对新区土壤中8种重金属As、 Cd、 Cr、 Cu、 Hg、 Ni、 Pb和Zn进行土壤环境质量监测,最少合理采样数分别为1 077个、 270个、 120个和767个、 192个、 86个.土壤各重金属元素可监测最小变化量(MDC)介于0.0025~2.54 mg·kg~(-1)之间.在不同的重金属年变化速率下土壤重金属监测所需要的重访间隔时间不同,在目前调查区重金属年变化速率条件下,调查区土壤监测所需要的重访间隔时间在2 a左右.  相似文献   
553.
文章针对目前生态文明建设水平评价指标体系信息不充分的局限,引入百度指数,从生态经济、生态环境、生态宜居及生态文化等4个方面构建贵州地级市生态文明建设水平评价指标体系,并选取2013~2017年贵州9个地级市的指标原始数据,运用灰色关联投影法对贵州9个地级市的生态文明建设水平进行实证评价。结果表明:从空间上看,黔东南州、黔南州和黔西南州的生态文明建设水平位列全省前3位,远超其余6个地级市;从时间上看,贵州9个地级市的生态文明建设水平都呈现出波动增长的态势,其中贵阳市、毕节市和铜仁市的增幅位列前3位。样本期内,贵州各地级市生态文明建设水平之间的差距逐步缩小,但区域间呈现非均衡发展的态势。  相似文献   
554.
Summary Croatia, as a Mediterranean country in the south-eastern part of Europe, is an area with a characteristic flora and fauna. The ornithofauna of Croatia reflects that it is a breeding area for some of the globally endangered bird species, as well as a site for the spring/autumn passage and the wintering of European migratory birds. Many ornithologically significant localities are designated and there are 20 ornithological reserves and four wetland sites that are on the list of the Ramsar Convention.In Croatia, there are four governmental organizations dealing with scientific research on birds of which the Institute for Ornithology of the Croatian Academy, of Sciences and Arts is that with the longest tradition. There are also many non-governmental organizations dedicated to the protection of environment, but only the Croatian Society for Bird and Nature Protection is dedicated mostly to bird protection. There are not many sources of funding for research and the protection of birds; the chief source being the Ministry of Sciences and Technology of the Republic of Croatia.Croatia has to establish new legislation according to European criteria and The Hunting Law, The Nature Protection Law and The Environment Protection Law have been recently accepted in Parliament. International Conventions, such as Bern, Bonn and Washington, have yet to be adopted. Foreign, hunting tourism, especially organized by fishpond authorities, is believed to be killing large numbers of protected water birds. A red data book exists only for plants and mammals and this makes biological assessments difficult.With the end of military operations and the reintegration of the occupied areas of Croatia, an assessment of the damage to the national parks and nature reserves, and to nature in general, will be necessary. Bird and nature conservation in Croatia remains promising, provided the legal control of the Croatian government over the occupied parts of the country is restored soon and international organizations give assistance.Dr Jasmina Muini is Croatian by birth and she has studied in Paris, Oslo, and Zagred where she gained her PhD. She is a President of the Croatian Society for Bird and Nature Protection, a member of the Croatian Parliament Board for Environmental Protection, vice-president of the Scientific Council of the Zoological Garden in Zagreb, and a member of other Croatian environmental bodies. She is a leading authority on the ornithofauna of the Croatian wetlands.  相似文献   
555.
采用γ-射线辐照法对城市污水厂剩余污泥进行预处理,从固体组分、可溶性组分及厌氧产气量等角度来探讨γ-射线辐照法改善城市污水厂剩余污泥厌氧消化特性的可行性.结果表明,经γ-射线辐照处理后,污泥的平均粒径减小,在辐照剂量为6.51~30.75 kGy范围内,粒径的减小率达30%~50%;可溶性有机组分随着辐照剂量升高而增加,当辐照剂量为19.4 kGy时,SCOD增加率达552.5%;与未辐照相比,污泥经2.48、6.51、11.24 kGy辐照处理后,厌氧消化累计产气量分别增加8.89%、19.74%和35.81%.γ-射线辐照法是一种有效的改善污泥厌氧消化特性的方法,11.24 kGy左右的剂量可作为污泥预处理的最佳剂量.  相似文献   
556.
热解技术在废旧印刷电路板处理及资源化中的应用   总被引:2,自引:0,他引:2  
综述了热解技术在废旧印刷电路板(printed circuit board,PCB)处理及资源化中应用的研究状况。热解技术可以改善和提高PCB中金属物质的回收效果,减少污染。同时,以热解为基础的PCB中非金属物质回收技术也有着很好的发展前景。PCB热解动力学的研究表明其在1000℃以下的热解过程可划分为分别服从不同反应机理的2个阶段。PCB热解产物中的油、气产物可以回收作为化工原料或燃料。PCB热解过程中含溴阻燃剂的转化和迁移规律以及热解产物中含溴污染物的控制和脱除、热解技术与其他PCB资源化技术的合理有效整合是今后研究的重点。  相似文献   
557.
降雨促渗对地表径流污染物负荷影响模拟试验研究   总被引:3,自引:0,他引:3  
建立模拟降雨装置,研究降雨条件下功能性材料与聚合物对降水土壤渗透性与地表径流污染负荷的影响。研究证实,沸石与PAM不仅能够促进降雨土壤水的人渗、延缓并减少地表径流.而且使土壤渗液和地表径流水质TSS、TN、TP、COD污染物负荷降低。以3kg/hm^2PAM、3kgPAM与7.5t/hm^2沸石、6kg/hm^2 PAM3种方式处理,径流COD负荷为对照的39.12%-69.76%、26.14%-46.63%和20.60%-28.09%;TN、TP与TSS负荷较对照分别减少44.36%-96.47%、66.63%-98.99%、93.71%-99.62%和50.46%~98.40%、83.30%~99.3l%、94.91%~99.72%和31.06%~77.23%、46.82%,86.22%、83.54%-95.33%。聚合物与功能性材料改良土壤是一种削减地袁降雨径流非点源污染的有效手段。  相似文献   
558.
炼厂柴油碱渣废水中含有成分复杂的酚及硫化物,因而其浓度较高。大港石化公司运用高浓度废水处理技术进行生物前期处理,其装置试运及柴油碱渣标定应用表明该技术先进。在生物处理过程中,工艺系统运行安全可靠,各项技术指标都达到或超过设计目标。其中,CODCr由处理前的34744mg/L降低到370mg/L,氨氮控制在50mg/L以下。高浓度废水处理技术流程简单,对周边环境无污染。  相似文献   
559.
大庆炼化公司从单一化工污水深度处理及回收利用发展为炼油、化工、生活污水统一处理和回用于循环水,既充分利用了现有污水处理场的处理余量,同时由于生活污水中含有比例适当的微生物需要的营养物质,对炼油和化工污水起到补充和稀释作用。这种处理方法既降低了工业污水对污水处理场的冲击,又起到了稳定水质的作用。  相似文献   
560.
The assessment of management effectiveness in protected areas, i.e., the evaluation of whether management strategies are actually helping to achieve stated goals, is becoming a priority. In any such evaluation, accurate information concerning the dynamics of the managed system is required—information that is gathered through monitoring. Few protected areas, however, have well-developed monitoring plans, and reserve managers are faced with a shortage of protocols for their design. This paper proposes a methodology, applicable to a wide range of situations, for designing such plans. The process begins with the precise definition of the aims of the monitoring plan, followed by the identification of key ecological processes and management objectives for the area, and finally the selection of a reduced set of indicators. These indicators are represented at three levels of growing complexity, allowing the plan to be followed in a modular fashion and in agreement with available resources.  相似文献   
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