新型聚合氯化铝铁絮凝剂处理污水处理厂污水的应用试验

通过混凝试验对新型聚合氯化铝铁、聚合氯化铁、聚合硫酸铁三种絮凝剂处理污水进行CODCr、TP、TN去除效果比较,并将它们进行絮凝效果和经济成本的对比分析.结果表明,用新型聚合氯化铝铁(PAFC)絮凝剂处理污水处理厂污水絮凝效果好,有良好的去除CODCr、TP、TN效果,且成本低廉,具有较好的应用性,使污水处理厂排放的出...     

水库疏浚底泥絮凝沉降室内试验研究

泥浆絮凝沉降效率是影响湖库疏浚工程进度的重要因素。为探索不同絮凝剂(有机、无机)对疏浚泥浆絮凝沉降效率的影响,以通济桥水库疏浚底泥为研究对象,通过室内试验先分析1种有机絮凝剂(PAM)和5种无机絮凝剂(PAC,FeCl₃,Na₂CO₃,Na₂SiO₃·9H₂O,KAl(SO₄)₂·12H₂O)单独作用下疏浚泥浆的絮凝沉降效果及上清液水质的优劣情况,然后对有机、无机絮凝剂进行优化组合试验,确定絮凝沉降效果和上清液水质最优的设计配比方案。试验结果表明:①PAM可以有效促进疏浚泥浆土颗粒的絮凝沉降,但对上清液的去浊率较低;CO₃^2-可以促进细颗粒絮凝结合成大颗粒,提高颗粒的沉降速率;Fe³⁺,Al³⁺具有改善上清液浊度的作用,但对促进泥浆絮凝沉降效果有限。②每1 000 mL疏浚泥浆中采用10 mL PAM+2 g PAC+2 g Na₂CO₃的有机-无机絮凝剂组合为最佳方案,既能快速促进疏浚泥浆的絮凝沉降,又能有效降低上清液的浊度。试验成果可为类似疏浚工程中选择絮凝剂最佳配比方案提供参考。     

不同污水处理工艺对磺胺抗生素去除效果与生态风险评估

采用固相萃取-高效液相色谱-串联质谱(SPE-HPLC-MS/MS)法调查研究了磺胺嘧啶(SD)、磺胺甲恶唑(SMX)、磺胺甲嘧啶(SMZ)、磺胺噻唑(STZ)、磺胺氯哒嗪(SPD)在北京市某污水处理厂7个代表性工艺单元中的浓度水平、去除特征,并运用风险熵(RQ)评估了总出水中残留目标物对受纳水体的生态风险。结果表明SD、SMX、SMZ、STZ和SPD在污水处理厂总进水中的平均浓度分别为199.0ng/L、288.4ng/L、19.3ng/L、2.1ng/L和5.1ng/L,在紫外消毒(UV)工艺出水中SD、SMX、SMZ的平均浓度分别为6.3ng/L、16.9ng/L和1.2ng/L,未检测到STZ和SPD。表明本污水处理厂能够完全去除STZ和SPD,对SD、SMX和SMZ的去除率分别为96.8%、94.2%和93.9%。除曝气沉砂池和二沉池工艺对个别目标物存在负去除率以外,5种磺胺抗生素经处理后,主要集中在二级与三级处理。5种磺胺类抗生素负荷量存在一定的周内变化。污水处理厂出水中残留抗生素对受纳水体中水生生物的生态风险均较低(RQ0.1),但多种抗生素共存的混合长期风险仍需深入研究。     

典型城镇化地区河流抗生素抗性基因分布 特征与风险评价

从南方某快速城镇化地区GM污水处理厂和MD河采集水样,通过培养基分离培养出与人类关系密切的LFE（乳糖发酵型大肠杆菌）,并以此作为主要研究对象,研究了GM污水处理厂和MD河中LFE的种群特征、动态数量变化。研究结果表明：在GM污水处理厂出水中的四环素耐药基因tetC含量明显高于香港沙田和美国某污水处理厂。这说明GM污水处理厂出水中tetC抗性基因污染较为严重,应该加以控制。而且,在GM污水处理厂出水和MD河中四环素耐药基因tetC和tetE的存在与LFE四环素抗性显著相关,因此,可以将其作为水环境四环素抗性基因污染指标用以评价其环境效应。     

胞外生物高聚物絮凝剂的研究进展(上)

就微生物分泌的胞外生物高聚物絮凝剂 (EBF)的研究和应用做了一个全面的综述 ,对化学絮凝剂与生物絮凝剂的比较 ,胞外生物高聚物絮凝剂产生菌的分离、培养条件、EBF的分类、化学组成和结构、絮凝机理和在絮凝过程中物理化学因素的影响以及生物絮凝的遗传学研究等进行了详细的分析讨论。     

浸没式超滤膜用于污水处理厂深度处理的试验

采用处理规模为31.2 m³/d的超滤中试装置,对江苏省某污水处理厂二沉池出水进行深度处理,着重考察超滤对浑浊度、SS、COD、TP、粪大肠菌群等的去除效果。结果表明:①将投加絮凝剂作为前处理手段可提高超滤时污染物的去除效果并降低跨膜压差增量,投加的硫酸铝质量浓度为2～4mg/L即可满足出水水质要求;②超滤对浑浊度、SS、COD、TP、粪大肠菌群等去除效果较好,出水中这些指标的值分别为0.33NTU、0.9mg/L、5.3mg/L、0.32mg/L和0 个/L,出水水质优于污水处理厂原深度处理工艺“微絮凝→砂滤→臭氧→氯消毒”的出水水质,满足GB/T 19923—2005《城市污水再生利用工业用水水质》规定的回用作循环冷却水的水质要求。     

奎河两岸污灌区浅层地下水氮污染特征及同位素示踪分析

地下水中氮污染主要包括铵态氮和硝态氮,特别是当铵(NH₄⁺)作为地下水的主要污染物时,由于其在含水层中迁移规律复杂,且难以去除,成为研究该问题的难点。在奎河徐州段两岸通过钻孔对浅层地下水进行取样测试分析,研究区浅层地下水中氮的存在形式主要为NH₄⁺,其次为NO₃^-。通过对δ¹⁵N-NH₄⁺同位素分析可知,地下水中约27.3%的NH₄⁺来源于化肥,约72.7%NH₄⁺来自于动物粪便、生活污水等高δ¹⁵N值的污染源;对δ¹⁵N-NO₃^-同位素分析可知,地下水中约有15.2%的NO₃^-来源于化肥和土壤有机氮,63.6%的NO₃^-来源于动物粪便和污水;约21.2%的地下水样本中δ¹⁵N-NO₃^-值超出了污染源的同位素值,可能产生了反硝化作用。     

城镇污水处理厂碳排放核算及减碳案例分析

针对城镇污水处理厂的温室气体(GHGs)排放，建立实用量化的指标核算与分析方法，并明确优化其产(排)污关联参数与排放因子的取值。以某10万m³/d城镇污水处理厂为研究对象，核算出其2021年实际碳排放强度约0.43 kg CO₂/m³,碳排放源贡献中，电耗因素居首(贡献碳排放权重为35%),而药耗因素在排放总量的权重为23%,因此节能降耗协同，对于减污降碳优化管控尤显重要。基于污水处理厂碳排放的显著性影响因子及其变化，需做好敏感性分析。抓好污水处理厂大功率耗电设备的效能与优化分析调控，调控平衡脱氮与除磷在生化反应单元的竞争矛盾，优选碳源种类、抓好碳源QC/QA、精细内外碳源投量(控制总体△C/N在7～8)及提升其利用效率，助力节约优先与绿色低碳目标。     

黄河上游典型小流域汭河水资源优化配置研究

针对汭河流域供水能力不足及流域辖区内用水部门用水量分配存在矛盾,进行水资源优化配置。以流域生活、工业、农业、生态等用水部门的用水总效益目标最大、余水量最大为目标,建立了多目标规划模型,采用多目标遗传优化算法求解,利用Topsis法对结果进行综合评价后求出最优的配置方案。结果表明：2020、2030年用水保证率(50%)下配置水量与预测水量相比工业用水量减少了528.336×10⁴、457.095×10⁴m³,生活用水量减少262.652×10⁴、342.059×10⁴m³,林牧渔畜用水量增加53.538×10⁴、84.098×10⁴m³生态用水量增加-7.905×10⁴、10.398×10⁴m³,农业减少641.047×10⁴、300.292×10⁴m³。通过优...     

陕北地区某污水处理厂设计案例及经验总结

陕北地区某污水处理厂总规模10万m³/d,本期设计规模5万m³/d,污水处理采用速沉池-AMAO-磁混凝沉淀-反硝化深床滤池工艺,污泥处理采用一体化连续深度脱水-高温好氧发酵工艺,出水执行《陕西省黄河流域污水综合排放标准》(DB 61/224-2018)。污水处理厂投产后,出水水质全面优于排放标准(月平均值COD 17.2 mg/L,NH₃-N 0.3 mg/L,TN 12.6 mg/L,TP 0.2 mg/L)。介绍了污水处理厂主要处理构建筑物及工艺设计参数,并针对高泥砂、高浓度、污水低温的水质特点,进行了工程设计经验总结,提出了选取低负荷工艺参数以应对污水低温、重视格栅及速沉等预处理单元以防止高泥砂冲击和设备堵塞磨损、设置全厂多级超越及优化生物池配水方式、完善污水保温措施及处理构建筑物防冻等。     

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。