多层渗滤介质处理微污染水体的中试研究   总被引：3，自引：0，他引：3  

侯立柱  周训  许靖华  叶文华  王文玉  杨生炯 《现代地质》2009,23(1):125-129

对传统的渗滤系统进行改进,采用多层渗滤介质系统,以期增大人工土层对颗粒有机物的接触氧化表面积,同时设置曝气装置保证好氧过程的氧气供应,可以大大提高污水地下处理系统的水力负荷。以北京典型的细砂、中砂、粗砂和砾石为填充材料,处理北京市海淀区上庄水库的污染水体,远优于类似的系统。现场试验结果表明,改进后的系统能创造良好的好氧/厌氧环境,对污染物去除效果良好,COD_Cr、TN、NH⁺₄-N和TP去除率分别达到了48.57%~94.87%、18.49%~70.21%、20.51%~87.50%和5692%~80.65%,出水达到了地表水Ⅲ-Ⅳ类水质标准。多层渗滤介质系统通过微生物的硝化、反硝化作用实现生物脱氮是去除氮的主要途径;土壤的吸附与沉淀作用是去除磷的主要途径。   相似文献   

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尹倩倩  楼益栋  易文婷 《大地测量与地球动力学》2012,32(6):123-128

????IGS????????????????????????????????????BKG??ESA??GFZ??GMV?????????????????????????IGS?o????????????ж??????????????????????RTN???????????????????????????????PANDA?????????IGS?????????????????ALBH???ж??PPP?????????λ?????????????  相似文献   

High mercury levels in hair samples from residents of Taiji, a Japanese whaling town     

Tetsuya Endo  Koichi Haraguchi 《Marine pollution bulletin》2010,60(5):743-747

We investigated the mercury concentrations in red meat from pilot whales consumed by some residents of the Japanese whaling town, Taiji, and in hair samples from 50 residents for their maker of mercury burden. The methyl mercury (M-Hg) level in the red meat was 5.9 μg/wet g, markedly higher than the US FDA action level and Cordex Alimentarius guideline level for predatory fish (1.0 μg/wet g). The average level of total mercury (T-Hg) in the hair from residents who ate whale meat more than once a month was 24.6 μg/g, whereas the average from the residents who did not consume any whale meat was 4.3 μg/g. The T-Hg concentrations in the hair from three donors exceeded 50 μg/g, the level for NOAEL set by WHO. The T-Hg level found in the Taiji whale meat consumers was markedly higher than that observed in the Japanese population overall (about 2 μg/g).  相似文献   

In situ Measurement of H2O and CH4 with Telecommunication Laser Diodes in the Lower Stratosphere: Dehydration and Indication of a Tropical Air Intrusion at Mid-Latitudes     

Georges Durry  Alain Hauchecorne  Joelle Ovarlez  Henri Ovarlez  Ivan Pouchet  Virginie Zeninari  Bertrand Parvitte 《Journal of Atmospheric Chemistry》2002,43(3):175-194

Telecommunication laser diodes emitting near 1.39 m and 1.65 m in combination with direct-differential absorption spectroscopy are efficient tools to monitor in situ stratospheric H₂O andCH₄ with a good precision error (a few percents), a high temporal resolution (ranging from 10 ms to 1 s), a large dynamic range in the concentration measurements (four orders of magnitude) and a high selectivity in the analyte species. To illustrate the capability of laser probing technique, we report balloonborne H₂Oand CH₄ simultaneous measurements obtained on October 2001 atmidlatitudes (43° N). The H₂O vertical profile achieved with the lasersensor in the lower stratosphere is compared with the H₂O data yielded by a balloonborne frost-point hygrometer. The total hydrogen mixing ratio in the lower stratosphere, 2[CH₄] + [H₂O], appears to beconstant at 7.5 ± 0.1 ppmv. Nevertheless, an unexpected largedehydration of 0.5 ppmv was detected by both the laser sensor and thehygrometer between 16 km and 23 km. We suspect the occurrence of a tropicalair intrusion into mid-latitudes. We support this interpretation using a high-resolution advection model for potential vorticity.  相似文献   

高空探测资料气球漂移的计算方法   总被引：1，自引：0，他引：1       下载免费PDF全文

李伟 王志文谢庄  刘凤琴徐磊 涂满红 《应用气象学报》2005,16(6):835-840

随着数值模式的不断发展，探空气球的漂移偏差越来越不可忽视。为了提高高空观测数据的质量，减小在探测过程中由于气球漂移造成探测资料在空间上的误差，中国气象局提出一套探空、测风报的空间、时间扩充编码方案。该文从探空雷达探测系统、探测原理分析出发，介绍了该方案计算方法，并用个例说明方案的使用方法及业务应用前景。  相似文献   

A numerical study of sea breeze circulation observed at a tropical site Kalpakkam on the east coast of India, under different synoptic flow situations     

C. V. Srinivas  R. Venkatesan  K. M. Somayaji  A. Bagavath Singh 《Journal of Earth System Science》2006,115(5):557-574

A simulation study of the sea breeze circulation and thermal internal boundary layer (TIBL) characteristics has been carried out at the tropical site Kalpakkam on the east coast of India, for operational atmospheric dispersion prediction. The community based PSU/NCAR MM5 Meso-scale meteorological model is used for the study. Three cases on typical days in summer (24 May 2003), southwest (SW) monsoon (1 July 2001) winter season (2 February 2003) with different large-scale flow pattern are studied. The MM5 model is used with 3 nested domains with horizontal grid resolutions 18 km, 6 km and 2 km and 26 vertical levels. The model is integrated for 24 hours in the above cases with initial and boundary conditions taken from NCEP-FNL analyses data. Observations of 10 meteorological stations and coastal boundary layer experiments conducted at Kalpakkam are used for comparison and validation of the simulation. The characteristics of simulated sea breeze and TIBL at Kalpakkam are seen to vary in the above cases according to the prevailing large-scale winds and surface fluxes. The sea breeze circulation is seen to develop early with larger strength and inland propagation in the summer case under the influence of moderate synoptic wind and strong heating conditions than in the SW monsoon and winter cases. The horizontal and vertical extents of TIBL are found to be larger in the summer case than in other cases. Although model parameters agree in general with observations, all the fine features are not clearly captured and some slowness in model sea breeze development is also seen. The results indicate the need to improve i) the initial conditions by assimilation of available surface/upper air observations to reduce model bias and ii) surface net radiation parameterisation. The model could predict the essential features of the local circulation and further improvement is expected with better initial condition data and incorporation of more realistic surface data.  相似文献   

岩石密度测量在黑龙江伊春地区花岗岩体就位机制研究中的应用     

赵焕利  刘宝山  李仰春 《华南地质与矿产》2006,(2):6-12

通过对伊春地区花岗岩体的密度特征的研究,认为该区晚奥陶世花岗岩体的侵位以构造扩展机制为主,气球膨胀作用为辅,最后发生了顶蚀作用.晚石炭世花岗岩是以强力旋转上升定位的气球膨胀作用机制为主,构造扩展机制为辅.晚三叠世-早侏罗世二长、正长花岗岩体就位过程中构造扩展机制起主导作用,岩浆底辟作用也较强;早侏罗世碱性花岗岩体岩浆就位过程中以强力的气球膨胀作用为主,构造扩展机制为辅.  相似文献   

Effect of marine economic development pilot policies on regional economic resilience: Based on quasi-natural experiments from coastal areas in China北大核心CSCD     

邢澜张广海 《地理科学进展》2023,(2):260-274

为了推动陆海统筹,转变和优化临海产业布局,制定和完善海洋开发政策与体制建设,推进海洋经济发展和海洋强国战略,提高沿海区域经济发展韧性水平,中国自2011年以来先后启动海洋经济发展试点工作。旅游业是中国沿海区域经济的重要组成部分。论文以海洋经济发展试点政策作为准自然实验,基于2007—2020年中国沿海地区各地级及以上城市的面板数据,运用多期双重差分模型,总结和评估该试点政策对区域经济韧性及旅游经济韧性的影响。结果表明:海洋经济发展试点政策的实施能够显著推动区域经济韧性及旅游经济韧性的提升;而新冠疫情事件作为调节变量,削弱了海洋经济发展试点政策对区域经济韧性的影响。在区域异质性上,海洋经济发展试点对中南沿海地区经济韧性的政策效应最明显,而对华东沿海地区旅游经济韧性的政策效应则更为显著。鉴于此,合理扩大海洋经济发展试点,因地制宜规划沿海区域经济体系,对防范系统性风险、提高区域经济韧性及旅游经济韧性具有重要意义。  相似文献