Characterization of industrial wastewaters using gel-permeation chromatography with multicomponent detection     

J. Oleksy-Frenzel  M. Jekel 《洁净——土壤、空气、水》1995,23(5):212-218

The gel-permeation chromatography system with multicomponent detection of organic carbon, organic nitrogen, organic halogen, and UV/vis absorption measurement is shown to be a useful tool for characterization of industrial wastewaters and wastewater treatment processes. The proposed system was used to investigate biologically treated wastewater from chemical industry, whereby one branch stream was identified to be the main source of persistent halogenated organics. Various treatment processes of pulp mill wastewater were also evaluated revealing that precipitation with aluminium is very effective for the removal of the high molecular fraction whereas the biological treatment is generally less selective. In the biological treatment of tannery wastewaters, it has been shown that the aerobic treatment, in contrast to anaerobic step, causes evident alterations of the composition of the polar DOC fraction. The nitrogen containing compounds are also better decomposed in the aerobic step compared to the anaerobic one.  相似文献   

东北农牧交错区水分条件的空间分异及其对土地利用的影响   总被引：2，自引：2，他引：2  

张军涛  艾华等 《地理科学进展》2001,20(3):234-239

大气降水、土壤水分和干燥度指数是在经度方向上控制区域景观格局的主要因素。本文运用最新的调查统计资料，对东北农牧交错区降水、土壤潜在蒸散量、干燥度指数及农作物生长期间土壤水分盈亏量的时间分布进行了分析；提出了研究区内作物生长季期间土壤潜在蒸散量的空间分布规律和干燥度指数的时空变化情形。结合水分条件的空间分布，提出了5种土地利用区域组合类型。  相似文献   

热机碎岩钻进工艺中钻进规程参数的理论分析   总被引：1，自引：0，他引：1       下载免费PDF全文

赵建康  孙友宏等 《地质与勘探》2001,37(2):94-96

通过建立数学模型，对热机钻进中钻进规程参数与机械钻速的变化规律进行了理论分析，并推导出了它们之间相互影响的关系式，对热机钻进中最优规程参数的确定具有重要指导意义。  相似文献   

水库水文情势与浮游植物群落结构   总被引：18，自引：0，他引：18       下载免费PDF全文

邬红娟  郭生练 《水科学进展》2001,12(1):51-55

综述和讨论了当前水库水文情势对浮游植物群落的影响研究,主要是水文情势对浮游植物数量、种类组成、物种多样性和群落的空间格局包括垂直和水平分布以及群落演替的影响.  相似文献   

石家庄市地下水中氮污染分析   总被引：25，自引：1，他引：25  

毕二平  李政红 《水文地质工程地质》2001,28(2):31-34

通过对石家庄市地下水中“三氮”污染状况的分析，发现硝酸盐是地下水中的主要氮污染物，利用氮同位素方法分析了地下水中硝酸盐氮的来源，讨论了人类开采地下水和施放环境物质对地下水中氮聚集的影响，在人类活动影响强度小的地区，地下水中的硝酸盐污染强度大大低于市区。NO3-浓度与硬度变化趋势表明：氮污染与硬度等指标值升高有一定的联系，但在不同的水文地球化学环境中，在迁移和转化等方面又有着自己的特性。  相似文献   

大庆油田西部地区地下水动态监测网优化设计   总被引：2，自引：1，他引：2  

秦延军  宋雷鸣  刘梅侠  刘金和 《水文地质工程地质》2001,28(2):21-25

大庆油田地下水动态监测,网（用水文地质定性方法建立）历经30多年的开采，需要进行定量优化设计，本次研究采用卡尔曼滤波技术与地下水流系统确定－－随机性数值模型相耦合的方法，首先对现有监测网进行质量评价，计算结果表明：监测网在漏斗区（地下水集中开采区）应增加监测孔的数目，调整监测孔的位置，为此，我们拟订了6套12个备选方案，从中选取了由88个监测孔组成的监测网，此监测网无论从监测目标上还是经费上都是最优的。  相似文献   

理塘毛垭温泉近期特大异常的调查与分析     

贾晋康  张庆云 《四川地震》1996,(2):32-37

本文首次弄清了毛垭温泉测点的局部地质环境，确定了测泉的水文地质性质和类型，弥补了建点基础资料之不足。采用常规的调查追踪方法对该前兆观测点近期出现的特大异常进行了较为详细地落实，并简要分析了调查结果。  相似文献   

Surface NO and NO2 mixing ratios measured between 30° N and 30° S in the Atlantic region     

F. Rohrer  D. Brüning 《Journal of Atmospheric Chemistry》1992,15(3-4):253-267

Surface NO and NO₂ mixing ratios were measured aboard the research vessel Polarstern during the mission ANT VII/1 from 24 September to 5 October 1988. The measurements were taken along the meridian at 30° W in the Atlantic region covering latitudes between 30° N and 30° S. The average mixing ratios were about 12 pptv NO/30 pptv NO₂ in the Northern Hemisphere and about 7 pptv NO/22 pptv NO₂ in the Southern. Elevated mixing ratios of 20 pptv NO/70 pptv NO₂ were found at 12° N (probably due to air masses originating from the surface of West Africa) and in the region of the ITCZ between 8° N and 5° N. Because of probable contamination by the ship, the measured mixing ratios mostly represent upper limits.  相似文献   

震兆图象的远程遥联性     

王泽皋  孙佩卿 《内陆地震》1992,6(2):121-130

通过研究我国一些震情窗口成组震兆与大陆及边邻Ms≥7.0级地震的整体链式活动的对应关系,指出这些窗口的成组震兆具有远程遥联的特点。对这种特点的深入研究将有可能为我国大陆及边邻地区地震活动的总体大形势作出估计。  相似文献   

Nitrogen emissions into freshwater ecosystems: is there a need for nitrate elimination in all wastewater treatment plants?     

Thomas Petzoldt  Dietrich Uhlmann 《洁净——土壤、空气、水》2006,34(4):305-324

Excessive inputs of phosphorus and nitrogen are the main reasons of eutrophication of inland waters and coastal areas. Large efforts have been made to control phosphorus, but the measures to reduce nitrogen emissions failed at least partly. While it was possible to reduce nitrogen emissions from industry and municipal wastewater treatment plants, diffuse sources are showing only very minor decline. Examples of limnetic, marine and coastal systems are given to review the current knowledge about nitrogen transformation and the effects of nitrate in the environment. When N is the limiting nutrient in a particular water body, this does not necessarily mean that phytoplankton is controllable by NO₃^– removal. In systems with problems due to a high redox‐sensitive internal phosphorus load and under certain constraints, nitrate may be used as an ecotechnological measure to prevent anaerobic phosphorus release from sediments. Model simulations are used to demonstrate this. A schematic model of redox‐mediated temporal phosphorus storage in riverine lake sediments with short retention time is proposed. We conclude that while anthropogenic nitrogen emissions are a global problem, no fast and simple single solution exists. Additional nitrogen removal in wastewater treatment will have no effect, as long as diffuse sources and nitrate concentrations in groundwater remain at a high level. Emission reductions should be achieved in an integrated way, taking direct and indirect effects into account. In this sense, case by case decisions and a new definition of “sensitive areas” are required.  相似文献