扬水曝气技术在河道型深水水库水质原位修复中的应用

以西安市地表饮用水水源—黑河金盆水库为研究对象,采用扬水曝气技术修复其受污染原水水质。结果表明,该项技术应用于大水深水库水质原位修复改善是可行、有效的;在扬水曝气器混合充氧作用影响下,金盆水库季节性缺氧/厌氧状况得到遏制,底泥表层DO浓度均维持在2mg/L以上;沉积物中氮、磷、有机质等内源释放过程明显减弱,藻类繁殖生长受抑;出水水质中TP、NH3—N、CODMn、叶绿素a等指标浓度较2008年同期分别削减46.7%、69.5%、22.4%及53.6%,水质改善效果明显。     

水厂示范工程滤池处理排涝期水质的试验研究

针对排涝期水中高氨氮和有机物污染问题,研究了示范工程滤池联用曝气系统对水中氨氮、亚硝酸盐氮、CODMn和UV254的去除效果。结果表明高压增氧曝气对增加滤池水中的溶解氧含量最有效,活性无烟煤和活性炭滤池对污染物的去除效果显著优于砂滤池,高压增氧曝气与活性无烟煤滤池联用对污染物的去除效果最好,对氨氮、亚硝酸盐氮、CODMn和UV254的平均去除率分别达到73.57%、87.93%、42.65%和37.21%。     

复合功能型湿地组合工艺对微污染河水特征污染物的净化效果研究

针对微污染河水中特征污染物的去除问题,设计了3种复合功能型湿地组合工艺系统,研究其对水体中的汞Hg~(2+)、总氮和总磷的处理效果,结果表明:3种组合工艺去除Hg~(2+)的最佳水力停留时间HRT均为1d,且去除率可达95%以上,组合工艺一和二对Hg~(2+)的去除效果较组合工艺三稍好,并验证了铜Cu~(2+)的存在对湿地系统中Hg~(2+)的去除具有明显的抑制作用;组合工艺一、二和三对总氮的去除率分别可达60.82%、54.24%和54.84%;3种组合工艺的出水中总磷浓度均可满足Ⅲ类水质要求。     

ABR—好氧组合工艺对农村生活污水处理效果研究

研究了厌氧折流板反应器(ABR)分别与跌水曝气和曝气生物滤池组合工艺对农村生活污水中COD_(Cr)和氨氮的去除效果,并对两种组合工艺去除效果进行了比较。结果表明:采用ABR—好氧组合工艺处理生活污水,COD_(Cr)的平均去除率基本上稳定在84.2%左右,这说明生活污水经过ABR厌氧反应器和好氧处理后,能有效去除污水中的有机物;在后续好氧段,采用跌水曝气作为后处理,COD_(Cr)去除率比单独采用ABR提高了9.5%,采用曝气生物滤池作为后处理,COD_(Cr)去除率提高了24.9%,与ABR—跌水曝气相比,采用ABR—曝气生物滤池去除COD_(Cr)的效果较好;ABR—好氧组合工艺对氨氮的去除效果较差,达不到理想的去除效果。     

微絮凝-超滤组合工艺处理微污染原水的试验研究

对微污染水源水采用微絮凝-超滤组合工艺进行中试研究,结果表明,组合工艺出水水质稳定,对浊度、COD_(Mn)、UV_(254)、>2 μm颗粒物和原生微生物的去除都有很好的效果,去除率分别高达99.8%、48.5%、73.4%、99.9%和99.9%.     

沸石-活性炭组合工艺处理微污染原水的研究

为改善水质 ,研究了沸石与活性炭 (GAC)组合的新工艺。沸石不仅具有去除水中浊度的作用 ,而且还可去除水中氨氮和部分有机物。沸石与活性炭的吸附性能有互补特点 ,沸石 活性炭组合工艺可有效去除污染物。试验结果表明 ,沸石对CODMn的去除率在 10 %左右 ,对浊度、氨氮、三氯甲烷的去除率分别在 6 0 % ,95 %和 4 0 %以上。沸石 活性炭组合工艺对水中苯酚、阴离子洗涤剂(LAS)和三氯甲烷的去除率分别在 6 0 % ,89% ,99%以上     

微污染水源水生物接触氧化处理工艺的启动与运行工况的调节

采用基于穿孔管曝气方式和ＹＤＴ型弹性立体填料的生物接触氧化工艺处理微污染水源水。分析了水源水自然接种条件下的工艺启动过程，研究了不同气水比运行条件下污染物的去除效果。处理系统形成稳定的氨氮去除率和硝酸盐氮生成率是工艺启动过程完成的主要标志；工艺运行中的气水比由生物硝化过程决定，气水比影响氨氮去除率和氨氮去除的稳定性，针对不同的进水氨氮浓度应采用相应的气水比     

微生态菌剂直投技术原位修复微污染水源水的试验研究

应用微生态菌剂直投技术处理城市微污染水源水体是控制季节性水质污染和水体富营养化的重要方法。采用实验室模拟的方法,研究了筛选制备的生态菌剂在自然条件下不同投加量对水质净化效果的影响。试验进行了32d,结果表明,微生态菌剂原位直投技术用于水源水质的原位改善是可行有效的,对水中主要污染物指标及其去除率分别可达到:氨氮100%、硝态氮76.2%、总氮80.9%、总磷90%、TOC 67.6%和CODMn40.6%;微生态菌剂可与水体的土著菌种叠加形成稳定的生态位,充分发挥了同步硝化反硝化作用。     

纯氧预曝气-生物过滤组合工艺处理微污染水中试研究

采用中试规模设备研究纯氧预曝气和生物过滤组合工艺对微污染水源水中多种污染物的处理效果。在沉淀池末端进行纯氧预曝气,能够提高溶解氧浓度至9.43~13.05mg/L,比较了活性无烟煤和活性炭两种滤料生物过滤工艺。原水氨氮为3mg/L时,出水氨氮平均值为0.07mg/L,且无亚硝态氮积累,CODMn平均去除率为71.72%,出水CODMn浓度均值为0.94mg/L,铁离子平均去除率为98.29%,出水铁离子浓度均值为0.011 mg/L,对典型臭味物质二甲硫醚的去除率为95.24%。结果表明活性无烟煤和活性炭两种滤料的性能类似。纯氧预曝气-生物过滤组合工艺适用于水厂常规处理工艺改造,对传统水厂技术升级具有重要的价值。     

新型超高分子量聚乙烯管式微滤膜处理高铁地下水的试验研究

采用新型超高分子量聚乙烯管式微滤膜为过滤介质,研究了预曝气-微滤组合工艺对高铁地下水的处理效果.结果表明:预曝气-微滤组合工艺对铁的去除率达90%以上,比单独微滤提高40%～60%,出水铁浓度小于0.1 mg/L,满足饮用水卫生标准;且有曝气时有毒有害微污染物去除效率高,对TOC、UV_(254)和UV_(410)的平均去除率分别为41.5%、82.1%和88.7%;有无曝气时对浊度的去除影响不大,去除率都大于95%,出水浊度小于0.2 NTU.铁等无机物是造成膜污染的主要原因,用2%～3% HCl清洗管内壁后再用清水反冲洗是处理此类膜污染的简单有效方式.     

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。     

Serial discontinuities in a Rocky mountain river. I. Distribution and abundance of plecoptera

Samples were taken year-round at eleven sites along the altitudinal profile (2900-1400 m a.s.l.) of the Gunnison River, a 329 km tributary of the Colorado River, to document the distribution of the Plecoptera and to evaluate responses to hypolimnial-release dams in the headwaters and middle reaches. Twenty-two species were present, with the greatest species richness occurring in an unregulated segment upstream of the middle reach dams; average nymphal biomass over the study period (175 organisms, 395 mg dry mass m^?2) was also greatest in this segment. Only four species (58 organisms, 48 mg m^?2) were present in the tailwaters of the headwater dam and values were greatly reduced (nine species; 35 organisms, 180 mg m^?2) below the middle reach dams. The stonefly community recovered ca. 80 km downstream from the last dam (15 species; 244 organisms, 250 mg m^?2), apparently in response to natural resetting of environmental conditions corresponding to those above the middle reach dams. At the most downstream site (11) only four species (four organisms, 16 mg m^?2) were present. The observed distributional pattern is a classic serial discontinuity in response to hypolimnial stream regulation in a temperate latitude river.     

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。     

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.     

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。