不同径流条件下钱塘江突发性水污染事故影响的预测模拟

采用二维潮流水质模型对钱塘江河口突发性水污染事故对水质的影响进行了模拟预测。分析结果表明:随着上游径流流量加大,污水团输移的速度明显加快,最大浓度也有所降低。同时随着污染物在输移过程中稀释扩散,超标总历时沿程逐渐增大,污染物最大浓度沿程逐渐降低。模拟及计算结果显示:突发污染事故后,加大上游的下泄流量,对加快污染团下移、稀释污染团从而降低污染物浓度的作用非常明显,模拟结果可为处理突发性水污染事故提供提供重要的理论依据。     

河流环境中硝基苯的归趋模型研究

河流发生硝基苯污染事件发生后,将对沿岸的生产生活产生较大影响。为了分析污染物在下游河流中的时空分布情况,以北方某江段突发硝基苯污染事件为研究对象,基于河流水质数学模型理论及苯污染物迁移转化规律,建立了一维水流和硝基苯迁移转化模型。所建模型涉及硝基苯光降解、挥发、吸附与沉积等多方面,系统地考虑了硝基苯在水、气和固三相间的转化。利用所建立的模型对突发污染事件的河段进行了水质模拟分析,揭示了事故发生地河流中硝基苯的时空分布情况,模拟结果与实测结果较为吻合,可为有关部门处理突发污染事故提供决策依据。     

基于ADCP测量的钱塘江主要断面污染物通量研究

用声学多普勒流速剖面仪（Acoustic Doppler Current Profiler，ADCP）获取河流断面的流量资料，结合水质分析所得的高锰酸盐、氨氮、总磷、石油类等污染物浓度资料，分析了钱塘江主要断面的污染物通量。结果表明，污染物通量研究将水质和水量统一起来考虑，很好的反映了污染负荷大小，是全面了解和评价河流主要断面污染物输送量和贡献量的有效手段，今后在治理流域水污染时应重视对河流污染物通量的研究。     

跨行政区污染源对下游哈尔滨饮用水源地的风险分析

文中分析了对哈尔滨水源地断面水质影响的污染来源,并在主要污染来源吉林市选择非持久性污染物COD指标、持久性污染物硝基苯,模拟突发性水污染事件,进行了污染风险分析。结果表明,当吉林市发生持久性污染事故时,河流中的削减是相当有限的,只要稍微超标时,对下游水源地的影响都是很大的。     

突发性水污染事故有机废水处理技术研究进展——以松花江硝基苯污染为例

重大突发性水污染事故的危害不仅造成人民生活质量下降,而且带来巨大的经济损失.常规突发性水污染事故的处理技术包括人工、物理、化学、生物等方法.通过对2005年松花江硝基苯污染事故的研究,发现污染物在水体、冰层、底泥中均有分布,对环境中的水生动植物产生一定影响,并且污染了地下水;采用活性炭吸附技术取得了很好的处理效果.今后应加强对特定污染物的污染特性、应急处理及污染修复技术的研究;在新建和改建污水处理厂时,应考虑特定污染源的应急处理,做好事故发生前的应急准备工作.     

原水输水渠道中粉末活性炭吸附污染物的模拟研究

在原水输水管渠中投加粉末活性炭,对污染原水进行预处理,已经成为水源地突发污染事故条件下的应急处理技术手段。本文提出了原水输水渠道中粉末活性炭动态沉降条件下,粉末活性炭—污染物耦合数学模型,以水源地硝基苯浓度超标为例(分别超标2、5和10倍),模拟了粉炭对硝基苯的吸附净化效果。得出基本结论为:粉炭吸附污染物的效果既与水流条件(实际水流剪应力或供水水量)有关,也与输水渠道的断面水深有关。在相同的粉炭投加浓度条件下,水流剪应力越低,断面水深越低,污染物吸附平衡浓度就越高。当水源地水质严重超标时(超标5–10倍),应将增加粉末活性炭投加量作为解决方案;而当水源地水质超标不明显时(超标2倍),可在合理调控供水水量和粉炭投加量的条件下,达到供水水质要求。该研究建立的数学模型,对突发污染事故条件下城市应急供水,具有借鉴意义。     

松花江水污染带给我们的重大启示

2005-11-13吉林石化公司双苯厂发生爆炸,造成约100t双苯和硝基苯流入松花江.给沿江城乡人民带来了灾难性的损失.文章从9个方面说明了松花江水污染带给我们的重大启示.     

应对突发性水污染事件的水动力与水质模型

突发性水污染事故不仅造成巨大的经济损失,而且造成社会的不安定和生态环境的严重破坏。以松花江水污染事件为例,通过对出库流量的控制,结合水质模型调算,得出污染物消减的耗时及相应的河道水位情况。采用数学公式计算出河道内的通航水位,与模型调算后的水位相比较,检验通过调度水库出库流量来稀释污染物时,其相应河道水位是否影响到河道的通航情况,从而确立水库应急调度总原则。     

明渠突发水污染导流退水工况的模拟

我国是一个水污染事故多发的国家,在南水北调工程全面通水前,需要提前针对可能发生的突发水污染事故开展研究。通过利用SMS水动力学软件,以中线某段为例,模拟分析明渠中水的流动状态及突发水污染时污染物的扩散过程;并在此基础上分析采用设置导流坝配合退水渠进行污染团导流的应急处置效果。以期为渠道管理和污染事故处理提供理论和技术支持。     

基于Matlab的大连地区突发水污染事件预报模型研究及应用

本文基于Matlab软件对大连地区独流入海的季节性河流污染物扩散进行模拟,并以挥发酚为例进行水污染动态时空可视化展示,结果发现：污染团在降解过程中随着水流向下游漂移,污染范围有所增加,但浓度也在不断降低,并且汛期污染物浓度降低与扩散范围远大于非汛期。对污染源下游1000m处应急入连取水口处污染物变化情况进行模拟。研究发现：该处污染物浓度变化为先增加后减少,并存在最大峰值,由此可得到此处污染物预警的开始与解除时间。该研究能够为山地丘陵地区季节性河流发生的水污染事故水质安全预警预报提供关键技术支撑,促进水生态友好和行业科技的进步,具有广阔的应用前景。     

地下厂房施工过程的三维非线性数值模拟分析

根据冗各电站地下厂房开挖支护的施工顺序,以隐式杆单元模拟锚杆,以壳单元模拟混凝土喷层,采用三维非线性有限元技术,对洞室群的开挖支护动态过程进行了模拟计算。通过三维非线性有限元计算分析得到:洞室群动态开挖过程中围岩应力变形的分布规律,围岩塑性区的发展规律,锚杆受力变化情况。计算结果表明:整个开挖过程中,洞周围岩位移变化规律正常,量值较小,塑性区主要分布在洞室周边,围岩稳定性较好;但在洞室交叉口处围岩的变形较大,出现较大范围的塑性区,在此基础上提出了支护措施优化方案,并对优化方案的效果进行了评价。     

Evaluation of freshwater mussel relocation as a conservation and management strategy

The relocation of unionacean mussels is commonly used as a conservation and management tool in large rivers and streams. Relocation has been used to recolonize areas where mussel populations have been eliminated by prior pollution events, to remove mussels from construction zones and to re-establish populations of endangered species. More recently, relocation has been used to protect native freshwater mussels from colonization by the exotic zebra mussel Dreissena polymorpha. We conducted a literature review of mussel relocations and evaluated their relative success as a conservation and management strategy. We found that 43% of all relocations were conducted because of construction projects that were forced to comply with the Endangered Species Act 1973 and that only 16% were monitored for five or more consecutive years. Most (43%) relocation projects were conducted from July to September, presumably a period when reproductive stress is relatively low for most species and the metabolic rate is sufficient for reburrowing in the substrate. The mortality of relocated mussels was unreported in 27% of projects; reported mortality varied widely among projects and species and was difficult to assess. The mean mortality of relocated mussels was 49% based on an average recovery rate of 43%. There is little guidance on the methods for relocation or for monitoring the subsequent long-term status of relocated mussels. Based on this evaluation, research is needed to develop criteria for selecting a suitable relocation site and to establish appropriate methods and guidelines for conducting relocation projects.     

基于模型试验的河床砂砾石层基本特性研究

为了经济可靠地确定深厚覆盖层的基本特性参数,以大渡河双江口水电站坝基河床砂砾石层基本特性研究为工程背景,进行大尺寸模型试验,研究河床砂砾石层的旁压模量和动探击数随密度、级配以及上覆压力的变化规律。根据室内模型试验结果,结合现场旁压试验及钻孔试验成果,推断出坝址区河床砂砾石相关层位的密度,并依此进行砂砾石室内力学试验,获得设计所需力学参数。研究成果可为深厚覆盖层基本特性测试提供新的方法。     

基于BP神经网络-马尔科夫链模型的隧道围岩位移预测

在隧道工程施工中,围岩位移预测起着很重要的作用。将BP神经网络-马尔科夫链模型引入到隧道围岩位移预测中来,通过对训练样本的学习,利用BP神经网络实现了对位移时间序列的滚动预测,同时得到了实测值与预测值的相对误差;在此基础上利用马尔科夫链对相对误差进行修正,有效地提高了预测结果的精度。并将该模型应用于某公路隧道拱顶下沉位移时序预测中,结果表明该模型具有精度高、科学可靠的特点,为隧道围岩变形的预测提供了新的途径。     

Short communication. Pipelines as a refuge for freshwater snails

In the lower River Murray, Australia, populations of gastropods have declined markedly over the past 40 years. Of the native fauna of about 18 species, only the ancylid Ferrissia petterdi remains common (but in patches), and another five species feature in sporadic local resurgences. Until recently the viviparid Notopala was thought to be extinct. The introduced physid Physa acuta is widespread, but in low numbers. The decline probably is associated with flow regulation, high turbidity and the introduction of common carp. Snail populations have persisted, however, in irrigation pipelines fed from the river, where they periodically cause blockages. This paper reports the discovery of the only known populaion of Notopala hanleyi in a pipeline where the inner wall accumulates microbial and other organic matter, providing high quality food for snails. In the Murray before regulation most of the periphytic biomass was probably microbial, as fluctuating water levels would have maintained littoral communities in a highly productive, early state of succession his postulated that, by stabilizing seasonal water levels, regulation has promoted the production of filamentous green algae, an inferior food source, and so displaced snail populations from the open aquatic environment.     

浙江省水域调查录入系统的设计和应用

浙江省水域调查录入系统将调查数据与电子地图相整合,对分类水域数据进行统计计算,并对输入数据进行合理性和完整性检查,得到调查范围内现有水域的详细数据,实现了水域调查数据输入、计算、统计和查询的数字化管理,提高了工作效率和工作质量,为各地下阶段水域保护规划编制和水域管理工作提供了数据支持。对该系统的设计原则、功能和技术设计等作了介绍。     

基于CT-连续加荷水泥乳化沥青混凝土细观损伤规律研究

利用CT技术对水泥乳化沥青混凝土的细观损伤过程进行实时扫描观测,获得了混凝土试件在连续加荷下的CT图像。通过采用直观分析法、CT数分析法、CT数与损伤变量关系3种方法分析表明,水泥乳化沥青混凝土的破坏过程可分为压密、扩容、裂纹扩展、破坏4个阶段,同时混凝土在受压过程中具有韧性,在极限荷载之前各断面处于压密和微扩容的强化阶段,极限荷载之后混凝土从损伤到破坏发展比较平稳。     

Automated system for removal and pneumatic transport of fly ash from electric precipitator hoppers

A system for removal and pneumatic transport of fly ash is examined, in which air pulses act on batches (pistons) of ash formed in a duct. Studies are made of the effect of several physical parameters on the force required to displace a piston of ash and these serve as a basis for choosing a system for removal and pneumatic transport of ash simultaneously from several hoppers of an electric precipitator. This makes it possible to separate the ash particles according to size without introducing additional components. Formulas are given for calculating the structural and dynamic parameters of this system and measurements of indirect dynamic parameters are used to calculate the input-output characteristics of the system. In order to optimize the system, configurations for summing several ducts into a single transport duct for pneumatic ash transport are proposed. Some variants of dry ash utilization and the advantages of producing of size-separated particles are considered. __________ Translated from élektricheskie Stantsii, No. 2, pp. 26–30 (2008).     

The flood pulse advantage and the restoration of river-floodplain systems

The ‘flood pulse advantage’ is the amount by which fish yield per unit mean water area is increased by a natural, predictable flood pulse. Evidence for this increase is presented from tropical and temperate fisheries. It is argued that increasing multispecies fish yield by restoring the natural hydrological regime is consistent with increasing production of other trophic levels and with restoration from ecological and aesthetic viewpoints. When applied to a river-floodplain system, this restoration would provide a large, self-sustaining potential for recreation, commercial exploitation, and flood control. An interim ‘natural flood pulse’ restoration approach is proposed for systems modified for navigation. This approach approximates the natural hydrological regime in a river reach and is intended as a first step in the long process of restoring the watershed.     

浅谈天湖水电站水轮机运行故障及处理措施

简述天湖水电站投运以来各种故障的表现形式，分析其原因，提出了相应的处理方法及措施，并对合理利用国内外设备提出建议。