多种修复技术对城市内河水质及微生物群落的影响

采集城市内河水样,分别采用曝气增氧、碳源添加、生物投菌和综合修复等技术,在实验室进行水质修复模拟实验,并以水质参数、微生物多样性及丰度为鉴定指标,分析不同修复技术对城市河流水质的修复效果及其对河流微生物群落结构的影响。结果表明,曝气、生物投菌和综合修复技术可以提高河流微生物群落结构多样性,水体微生物群落以变形菌门(Proteobacteria)、拟杆菌门(Bacteroidetes)、放线菌门(Actinobacteria)和疣微菌门(Verrucomicrobia)为主;而使用碳源添加技术的水样,河流微生物的多样性下降明显,变形菌门(Proteobacteria)的相对丰度达到了93%;水质修复方面,曝气增氧技术和生物投菌技术都仅能降低水体COD质量浓度,无法降低水体TN及NH+4-N质量浓度;碳源添加和综合修复技术,对水体TN和NH+4-N的去除效果明显,但投加碳源的河流水体中的COD质量浓度显著上升;相关性分析结果表明,影响水体微生物群落结构的主要环境因子为COD和DO。     

碳纤维生物接触氧化法处理黑臭水体过程中的微生物多样性演变特征

为了探讨碳纤维生物接触氧化法处理黑臭水体过程中,生长环境对细菌群落结构多样性特征演变的影响,利用高通量测序技术,对接种污泥以及设备内不同处理阶段的活性污泥、碳纤维膜上的细菌群落特征进行了研究。结果表明,随着挂膜的进行,设备内活性污泥的微生物种类逐渐减少,与接种污泥的细菌群落结构差异性越来越大,但是碳纤维膜E样品与稳定期D样品的细菌群落结构差异性较小。优势细菌菌群分析结果表明,在门类水平上达到20门以上,优势细菌种群以变形菌门、厚壁菌门、放线菌门、拟杆菌门的细菌为主,相对丰度约为75%～95%;纲类水平也达到20纲以上,主要以α-变形菌纲、β-变形菌纲、δ-变形菌纲、γ-变形菌纲为主。设备内活性污泥和碳纤维上的α-变形菌纲和γ-变形菌纲均高于接种污泥,梭菌纲含量低于接种污泥,说明采用活性污泥进行接种挂膜,细菌群落结构发生了较大变化。     

镇江市金山水厂活性炭池微生物群落结构解析

采用高通量测序技术,分析了镇江市金山水厂活性炭池微生物的群落结构。结果表明,8个炭池表层共检测到23种菌门,其中优势菌门2种,Firmicutes(厚壁菌门)和Proteobacteria(放线菌门);优势菌属为Bacillus(芽孢杆菌属)、Lactococcus(乳球菌属)、Enterococcus(肠球菌属)、Streptococcus(链球菌属)、Carnobacterium(肉食杆菌属)、Cronobacter(阪崎肠杆菌属)以及Pseudomonas(假单胞菌属)。这些均为专性需氧或者兼性厌氧菌,利用有机物作为碳源,实现水中有机污染物的去除;同一炭池不同深度的微生物群落差异不明显。     

北大港水库微生物群落的空间分布特征

天津北大港水库水质存在咸化问题，水质咸化可能会导致微生物群落组成和多样性发生显著变化。为探究 水质咸化条件下水库微生物群落组成的空间分布特征，于 2021 年 12 月在北大港水库采集表层、中层和底层的水 样，利用高通量测序技术，对北大港水库不同深度及上下游的微生物群落组成及多样性进行分析，并探究溶解性 总固体与微生物群落的关系。结果表明：北大港水库的溶解性总固体（total?dissolved?solids,?TDS）质量浓度在表层、 中层和底层存在差异，下游高于上游。微生物的主要优势菌门为变形菌门、拟杆菌门和放线菌门，变形菌门的相 对丰度均超过 50%。优势菌属是 Clade_III 未定属（相对丰度 1.10％～72.72?％）和黄杆菌属（Flavobacterium?相对丰 度 0.32％～20.09?％），Clade_III 未定属的相对丰度上游高于下游，黄杆菌属的相对丰度表层高于中层和底层。上 游水体表层的微生物群落组成与中层、底层的微生物群落组成存在显著差异，下游在不同深度微生物群落组成差 异不显著，中层和底层的微生物群落组成存在相似性。Chao1 和 Shannon 指数表现出表层<中层<底层，下游略高 于上游，微生物 Alpha 多样性指数随 TDS 质量浓度的增大而减小。在科水平上，Clade_Ⅲ能够耐受较高的盐度，但 当 TDS 质量浓度>3?000?mg/L 时其丰度降低。     

汾河柴庄水文站水体富营养及浮游植物群落特征研究

为研究汾河水体营养状态及浮游植物群落特征，于2021年5—10月对汾河柴庄站进行连续6个月水生态调查监测，评价汾河水体营养状态、水华等级、浮游植物群落特征，采用Pearson检验法进行藻密度与环境因子相关性分析，并采用DNA分子测序技术诊断微生物群落状态。结果表明：汾河柴庄站5—7月水质为Ⅴ类，8、9月为Ⅳ类，10月为劣Ⅴ类，主要超标项目为总氮、氨氮和化学需氧量；5—10月水体营养化程度均处于富营养状态，8、10月为轻度富营养，5、6、7、9月为中度富营养；共检出浮游植物6门36属52种，以绿藻门和硅藻门为主，蓝藻门、裸藻门、甲藻门、隐藻门次之。藻密度与Chl-a、DO、COD_Mn正相关，与水温、TN、TP、NH₃-N相关性不显著。分子测序诊断柴庄站水体细菌以Proteobacteria(变形菌门)、Actinobacteria(放线菌门)和Bacteroidetes(拟杆菌门)为主，真菌主要是Ascomycota(子囊菌门)、Basidiomycota(担子菌门)、Chytridiomycota(壶菌门)，其中Aspergillus(曲霉属...     

汉江上游干支流沉积物细菌群落多样性和影响因素

为了解汉江上游干支流沉积物细菌多样性以及确定性过程和随机性过程在沉积物细菌群落构建过程中的相对重要性,基于Illumina高通量测序技术,分析了环境因子对细菌群落组成的影响,采用非度量多维尺度(NMDS)排序探究了季节之间沉积物细菌群落的差异,并结合中性群落模型和标准化随机率量化了确定性过程和随机过程对群落构建的影响。结果表明：汉江上游及其支流细菌群落主要由变形菌门(Proteobacteria)、拟杆菌门(Bacteroidetes)、蓝藻门(Cyanophyta)、浮霉菌门(Planctomycetes)和酸杆菌门(Acidobacteria)等组成;细菌群落在不同季节有显著差异;地理距离和环境因子对细菌群落结构影响较小,确定性过程并未在细菌群落组成中起到主导作用;随机过程很大程度上影响了群落在秋季和春季的组成,是沉积物细菌群落构建的主导因素。     

人工湿地基质细菌多样性研究

分别采用PCR-RFLP和高通量测序方法,分析自由表面流人工湿地基质细菌多样性。2种方法均显示人工湿地基质中细菌主要分布在变形菌门,其中γ-变形菌纲和β-变形菌纲属优势菌群,其次为δ-变形菌纲、α-变形菌纲、厚壁菌门中的芽孢杆菌纲及酸杆菌门中的酸杆菌纲。但在优势种属水平上,2种分析方法得到的结果差异较大。人工湿地基质中存在亚硝化螺菌属、硝化螺旋菌属、Thioalkalivibrio、不动杆菌属、假单胞菌属、放线菌属、海旋菌、海单胞菌属及鞘脂菌属等参与脱氮除磷和降解有机污染物的微生物种类;同时也存在绿脓杆菌、弧菌属及黄杆菌属等致病菌或条件致病菌。研究也说明,PCR-RFLP和高通量测序法对湿地基质微生物多样性分析显示出了方法的优越性。     

典型屋面初期雨水径流污染特征及生物控制中试研究

为加强城市面源污染控制和推动生物滞留设施的实际应用,通过在线和人工监测方法考察了长沙市典型屋面雨水径流污染的变化规律及装配式高位花坛对污染物的去除性能,并采用Illumina高通量测序手段探究了设施介质中微生物群落的结构组成。结果表明：长沙市屋面初期雨水径流中COD和SS峰值浓度分别为22.9～153.0 mg/L和58.4～294.4 mg/L,具有一定的污染性且二者呈现正相关趋势;污染物浓度峰值出现在降雨开始后的30 min内且随着降雨历时的增加逐渐下降并趋于稳定;降雨量、降雨强度和降雨间隔时间的增加会加剧初期冲刷现象从而进一步恶化屋面径流水质;装配式高位花坛对COD、SS和NH₃—N的平均去除率分别为58.3%、85.3%和66.2%,屋面径流经过净化后水质明显改善;介质中的主要优势菌门为变形菌门、放线菌门、酸杆菌门和绿弯菌门,其中变形菌门相对丰度为30.0%～46.6%;反硝化过程更容易在出水端发生。     

活性炭净水工艺微生物安全性研究

采用基于16SrDNA的焦磷酸测序法对北京某水厂活性炭净水工艺各单元的细菌群落结构进行分析。结果显示,砂滤对细菌多样性影响较小,活性炭工艺使菌群多样性升高。活性炭颗粒上的细菌群落结构与各工艺出水差异明显。α,β和γ变形菌纲是工艺出水和活性炭上的优势菌,活性炭池可以有效去除α变形菌纲和γ变形菌,但加氯消毒后的出厂水中α变形菌纲比例很高。出厂水中的第一优势菌为嗜氢菌属,含量高达86.2%。出厂水和活性炭颗粒上发现了9种潜在致病菌,如短波单胞菌、黄色单胞菌和鞘氨醇单胞菌等,但相对丰度较低,对饮用水安全影响较小。     

城市供水系统中真菌群落赋存规律解析

城市供水系统中的耐氯真菌为面向直饮的高品质饮用水供应带来了新的挑战。以某城市供水系统为研究对象,借助培养法、宏基因组测序等方法对水厂不同处理工艺出水和二次供水中真菌的数量和群落结构进行了测定分析。经过水厂净水工艺处理,真菌菌落数有效降低;但相比出厂水,二次供水水箱中的真菌数量出现上升,表明存在真菌再生长风险。出厂水和二次供水中的真菌以根瘤菌属、壶菌属、曲霉属和镰刀菌属为主。曲霉是两水厂出厂水中检出频率和相对丰度最高的致病真菌,3月份最高丰度可达25.19%,建议应作为供水系统重点控制的对象。紫外装置对二次供水中耐氯真菌的数量和致病真菌丰度具有明显的控制效果。     

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。