气浮—水解酸化—IC—曝气—混合反应—砂滤工艺处理造纸制浆废水

采用气浮—水解酸化—IC—曝气—混合反应—砂滤组合工艺处理造纸、制浆生产废水,运行结果表明,当造纸废水水量12 000 m3/d、CODCr≤1 670 mg/L、BOD5≤750 mg/L、SS≤1 200mg/L,制浆废水水量6 000 m3/d、CODCr≤14 500 mg/L、BOD5≤5 100 mg/L、SS≤3 430 mg/L时,处理出水CODCr≤90 mg/L、BOD5≤30 mg/L、SS≤30 mg/L,可满足《制浆造纸工业水污染物排放标准》(GB 3544—2008)要求。     

SH-A节能型生物脱氮工艺处理焦化废水工程实例

采用SH-A节能型生物脱氮工艺处理氨氮含量高、有机物可生化性差的焦化废水。工程处理水量为1600m3/d。进水CODCr约2500mg/L,NH3—N约260mg/L。处理后出水各项指标均达到了《污水综合排放标准》(GB8978—1996)一级标准,其中CODCr≤100mg/L,NH3—N≤15mg/L。     

预沉—气浮—水解酸化—A/O工艺处理明胶废水

明胶生产废水中有机物、有机氮、Ca2+浓度高,对微生物活性有较大的抑制,采用预沉—气浮—水解酸化—A/O工艺对其进行处理,在进水pH9～12,CODCr≤3000mg/L,NH3—N≤30mg/L,TKN≤200mg/L情况下,出水CODCr80mg/L、NH3—N≤5mg/L,达到广东省《水污染物排放限值》(DB44/26—2001)一级标准,并分析了工程中需要注意的问题。     

燃料乙醇生产废水处理工程

采用UASB/IC-SBR工艺处理燃料乙醇废水,高浓度废水经UASB/IC工艺处理后与低浓度有机废水一起进入SBR池进行好氧处理.该工艺流程简洁、自动化程度高、管理方便,处理效果稳定,处理后出水CODCr≤60 mg/L,BOD5≤20 mg/L,SS≤60 mg/L,达到《污水综合排放标准》(GB 8978-1996)一级标准.UASB/IC反应器和SBR池的CODCr去除率分别达到85%和83%,BOD5去除率均达到90%.将厌氧段产生的沼气用于发电,经济效益显著.     

UASB—A/O工艺在丙烯酰胺废水处理中的应用

采用UASB—A/O工艺处理高氨氮废水,进水CODCr为2 000～4 000mg/L,NH3—N为250～350mg/L,SS为80～140mg/L,pH为4～9。出水NH3—N均在50mg/L以下,CODCr在150mg/L以下。该工艺耐冲击负荷能力强,处理效果稳定,经后续单元处理后,出水各项指标均达到《污水综合排放标准》(GB 8978—1996)一级排放标准。     

UASB—改良AB工艺处理高浓度钠盐纤维素醚类废水

某纤维素醚类生产企业,生产废水污染物浓度高、Na+浓度高,废水量为600 m3/d,采用UASB-改良AB工艺对其进行处理.工程实践表明:在进水Na+≤17 000 mg/L、CODCr≤4 500mg/L、SS≤2 500 mg/L、pH 7～8的条件下,出水可满足设计要求.     

EGSB—自养脱氮技术处理高浓度淀粉废水工程实践

淀粉生产废水含有高浓度有机氮,选用调节池—中间水池—EGSB反应器—自养脱氮池—二沉池—混凝沉淀池处理工艺,在进水COD≤8 000 mg/L、TN≤400 mg/L的情况下,处理出水COD＜60 mg/L,NH3—N＜10 mg/L,去除率分别可达98.9％和96.9％以上,该系统具有运行稳定,处理效果好的特点,出水水质可达《污水综合排放标准》(GB 8978-1996)一级排放标准,产生的沼气可作辅助燃料加热废水,具有良好的环境效益和经济效益.     

UASB—MBR工艺在啤酒废水处理中的应用

啤酒废水的主要特点之一是BOD/COD高,利于生化处理.南昌某啤酒厂产生的啤酒废水采用UASB-MBR工艺处理,取得了较好的效果.出水CODCr40～45 mg/L,BOD5 15～20 mg/L,SS 1～5 mg/L,各项指标都达到了<污水综合排放标准>(GB 8978-1996)的一级标准.     

SBR法处理制药废水的试验研究

采用SBR法处理制药废水。当进水CODCr为 2 4 0～ 110 0mg/L ,NH3-N为 14～ 55mg/L时 ,出水CODCr≤ 10 0mg/L ,NH3-N≤ 15mg/L ;CODCr的去除率 >90 % ,NH3-N的去除率 >70 %。     

印染废水处理与回用工程

针对印染低浓度废水可生化性差等特点,采用物化+生化+深度处理工艺进行处理,工程处理规模为2 000 m3/d,进水CODCdr≤300 mg/L、色度≤100倍、SS≤200 mg/L、总铁≤0.5 mg/L.出水CODCr≤50 mg/L、色度≤15倍、SS≤20 mg/L、总铁≤0.05 mg/L,可回用于印染生产.     

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。     

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.