化学除磷-水解酸化-厌氧接触-接触氧化工艺处理榨菜废水

榨菜废水的高含盐量和高氮磷对微生物有较强的抑制作用,处理难度大.以处理规模400 m3/d的重庆某榨菜厂废水处理工程为例,其进水COD 3 000～4 000 mg/L,BOD5 1445 mg/L,盐度1.5％～2.5％(以NaCl计),氨氮80～120 mg/L,总磷25～30 mg/L.通过驯化耐盐微生物为主体菌种,采用化学除磷-水解酸化-厌氧接触-接触氧化工艺进行处理,出水COD、BOD5、氨氮、总磷以及盐度平均分别为70.5 mg/L、14.9 mg/L、9.4 mg/L、0.46 mg/L以及1.53％,可以达到《污水综合排放标准》(GB8978-1996)一级标准.     

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。     

混凝沉淀—IC工艺预处理高浓度OE生产废水

脂肪酸聚氧乙烯酯(OE)生产过程中产生高浓度有机废水,用混凝沉淀—IC反应器预处理高浓度OE生产废水,当进水CODCr为6 000～9 000 mg/L、SS为800～1 500 mg/L时,出水平均CODCr、SS分别为780 mg/L、200 mg/L,CODCr、SS的平均去除率达到90%和85%,出水水质达到厂方的预处理要求,为后续主体工艺处理提供保障。     

小麦淀粉废水处理与沼气利用工程实例

采用厌氧MIC-好氧HTO处理小麦淀粉废水,其处理规模为2 000m3/d,进水COD为12 000~20 000 mg/L,BOD5为6 000~10 000 mg/L,SS为9 000~10 000 mg/L。处理后废水COD、BOD5、SS、NH3-N分别降至100mg/L、20mg/L、30mg/L、15mg/L以下,符合《淀粉工业水污染物排放标准》(GB 25461-2010)中新建企业水污染物直接排放浓度限值要求。系统沼气产量为10 000~13 000m3/d,作为燃料通入燃气锅炉,不仅解决了管通腐蚀问题所产蒸汽还可供车间利用。     

食品工业高盐高氮磷有机废水处理技术发展趋势

随着中国经济的高速发展,酱腌榨菜等制品的消费量大幅增加,我国榨菜生产主要产区分布于重庆、浙江、四川、湖南、湖北、安徽、江苏、贵州、山东、江西、福建等地,仅重庆就现有榨菜加工企业近100家,年产量在3 000 t以上的30余家,榨菜种植面积70余万亩(1亩≈667 m2),产值45亿元.近年来,榨菜生产规模化、集约化程度愈来愈高,并形成大量特色食品工业园区,在其生产过程中产生大量高盐高氮磷有机废水(10 m/t榨菜),该类废水具有盐度高(3％～15％)、有机物及氮磷浓度高(COD 3 000～41 000mg/L,TN 100～1 000 mg/L,TP 20～300 mg/L),溶解性有机质多,可生化性好的特点.由于高盐对微生物的抑制作用,常规处理难度大,排放水体造成河流及沿线农田土壤严重污染.     

微电解—芬顿—AAO—臭氧催化氧化—活性炭吸附工艺处理化工园区综合废水的中试研究

采用微电解—芬顿—AAO—臭氧催化氧化—活性炭吸附工艺处理化工园区综合废水,处理进水为化工企业处理后排放到园区污水处理厂的综合废水,通过对中试主体工艺的选择,关键流程和参数的选定,并就稳定运行效果进行了阐述.经过该工艺处理后,最终出水的COD、BOD5、氨氮、总氮、总磷的去除分别为92.26％、48％、94.93％、72.69％、77.6％,浓度分别为23.9 mg/L、6.5 mg/L、1.54 mg/L、11.8 mg/L、0.28 mg/L,出水水质达到《城镇污水处理厂污染物综合排放标准》(GB 18918-2002)中一级A的标准要求,满足污水处理厂的排放标准,该流程的运行费用为每吨水5.83元.     

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.     

UASB-两段接触氧化工艺处理淀粉废水

玉米淀粉生产废水污染物浓度高,悬浮物含量大,可生化性好.针对淀粉废水的特征,采用UASB-两段接触氧化工艺对其进行处理.工程实践表明,进水CODCr12 000 mg/L,BOD5 8 000 mg/L,SS 3 000 mg/L时,该工艺处理出水水质优于<污水综合排放标准>(GB 8978-1996)一级标准.运行成本约为0.792元/m3.     

SBR法处理煤化工废水中石油烃类的试验研究

采用序批式(SBR)活性污泥法处理煤化工废水.通过分析不同周期、进水浓度、pH、温度、DO与处理效果之间的关系,确定了SBR法处理煤化工废水的的最佳运行参数.试验结果表明,在SBR处理周期为24 h的条件下,进水CODCr为1200～1400 mg/L,石油烃类为50～70 mg/L,pH为6.8～7.1,DO为3.5 mg/L左右,温度约为25℃时,该工艺对CODCr和石油烃类去除效果较好,去除率分别为85％和76％.该工艺具有投资少、操作简单、运行费用低等特点.     

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。     

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。     

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。