深圳水源水藻类去除中试研究

采用正交试验和单因素试验设计方法,考察预O3、PAC、PAM和主O3投量对藻类去除的影响程度.中试结果表明,在深圳夏季高藻季节,当原水藻密度小于2×107个/L时,预O3、PAC、PAM和主O3投量分别为1 mg/L、1.5 mg/L、0.05 mg/L和2 mg/L可保障炭滤出水藻密度在105个/L(深圳市生活饮用水水质目标)范围内;当原水藻密度增加到2×107个/L以上(3.5×107个/L以下)时,可通过加大投药量,即预O3、PAC、PAM和主O3投量分别为1.8mg/L以上、2 mg/L、0.07 mg/L和2.5 mg/L,达到上述炭滤出水藻密度水平.     

粉末活性炭去除原水中阿特拉津突发污染的研究

利用中试装置研究了水源水阿特拉津突发污染的应急处理措施.试验结果表明:常规工艺不能有效去除原水中的阿特拉津,投加粉末活性炭(PAC)可有效去除阿特拉津,确保出水达到水质标准的要求;PAC投量为50 mg/L时,可使初始浓度为200 μg/L的阿特拉津降低到2 μg/L以下;KMnO4与PAC联用的去除效果比单独使用PAC略有改善但并不显著,预氯化则会降低PAC对阿特拉津和UV254的去除率.     

压力强化混凝沉淀过滤除藻工艺中藻毒素去除研究

为了探究压力强化混凝沉淀过滤除藻工艺中藻毒素的去除效果,试验对比研究了预加压和预氧化后的含藻水,经混凝沉淀、粉末活性炭吸附后的藻毒素去除效果,考察了不同粉末活性炭投加点及投加量对藻毒素去除效果的影响。结果表明,含藻水加压后混凝沉淀,藻类和浊度物质去除效果最优,蓝藻去除率达到96.2%,浊度降至0.49NTU。含藻水在加压和高锰酸钾预氧化后,水中藻毒素浓度未增加,而次氯酸钠预氧化后水中藻毒素浓度最大增幅为215.78%;对于加压水样,在混凝剂投加前30min或投加后7min投加粉末活性炭效果较好,粉末活性炭投加量为5~20 mg/L时,沉淀水藻毒素平均去除率分别达54.13%和53.57%,而与混凝剂同时投加则效果不佳。对次氯酸钠预氧化的水样,粉末活性炭与混凝剂同时投加时效果最好,沉淀水藻毒素平均去除率15.84%。     

强化混凝技术处理东太湖原水研究

在常规混凝工艺确定的最佳处理条件下,考察了单独高锰酸钾(KMnO4)和次氯酸钠(NaClO)预氧化、单独投加粉末活性炭(PAC)以及KMnO4和PAC联用对混凝处理东太湖原水的强化效果。结果表明,聚氯化铝和硫酸铝的最佳投加量分别为20mg/L和30mg/L,聚氯化铝的混凝效果明显优于硫酸铝;投加KMnO4对浊度、CODMn和UV254的去除均有一定程度提高,但不利于原水氨氮的去除;投加PAC有显著的强化混凝作用,各指标去除率均有所提高;KMnO4和PAC联用能进一步提高水中UV254的去除率;预氧化大大提高了混凝对氨氮的去除效果,投加1mg/L NaClO对氨氮去除率可达100%。     

高盐景观水体除磷、除藻药剂优选及复配

淡水盐碱化是全球范围内面临的一个新兴环境问题,其中城镇内人工景观水体表现尤为突出。高盐景观水体盐度大,导致植物不易生长,藻类逐渐成为优势种群,影响观感。通过絮凝法同时除磷、除藻,使景观水体恢复藻类爆发前的状态。研究11种絮凝药剂对TP、Chla(叶绿素a)的去除效率,其中PAC除磷效果很好,CPAM可以有效除藻。经过浓度梯度优选实验,优选出PAC和CPAM的最优投加浓度,并进行复配试验。复配结果为当PAC投加浓度10mg/L、CPAM投加浓度3mg/L时组合除磷、除藻效果最佳,TP平均去除率为92.52%,Chla平均去除率为98.32%。     

在线混凝-超滤联用工艺用于小城镇给水的应用研究

采用在线混凝-超滤联用工艺对某水塘水进行中试研究.试验结果表明,将常规处理作为超滤的预处理时,膜压差增加迅速,无法保持稳定运行.将在线混凝作为超滤的预处理时,膜压差增加缓慢.通过比较不同的混凝剂抑制压差和去除有机物的效果,发现聚硫酸铁均优于聚氯化铝.次氯酸钠和高锰酸钾预氧化的试验结果表明,尽管高锰酸钾去除有机物和三氯甲烷生成潜能的效果较好,但膜压差增加较快.在线混凝-超滤联用工艺处理后出水的CODMn可低于3 mg/L.     

混凝-气浮除藻工艺中混凝剂的选择

通过对比聚氯化铝、硫酸铝、聚硫酸铁和氯化铁的混凝—气浮处理效果,选择最合适的混凝剂进行后续研究。试验结果表明:对于藻密度1.6×10~(10)个/L左右的铜绿微囊藻原水,经处理后取得相近的出水效果时,聚合混凝剂比无机盐混凝剂投药量少很多,聚氯化铝比硫酸铝的用量减少70%以上,聚硫酸铁比氯化铁用量减少30%以上;对于铜绿微囊藻原水,铁系混凝剂对浊度、TOC的去除效果优于铝系混凝剂;铝系混凝剂对色度、藻密度的去除优于铁系混凝剂。     

载粉末活性炭过滤处理微污染原水的试验研究

载粉末活性炭(PAC)过滤集PAC吸附与过滤于一体,能够应用于微污染原水处理。配水试验结果表明:粒径为1.25-2.5mm,厚度为1000mm的聚苯乙烯滤料层能够用于载PAC过滤。影响过滤效果的主要因素为PAC载量和混凝剂投加量,当混凝剂T3010和聚氯化铝的投加量分别为0.09mg/L和2.5mg/L,PAC载量为2-3g/L滤料时,载PAC过滤处理浊度为20-40NTU的微污染原水的效果达到最佳,对CODMn和浊度都具有很好的去除效果。Z河水作为原水的试验结果表明:载PAC过滤对河水浊度、UV254、CODMn的去除率分别为97%-97.9%、50.9%-63.4%、68.5%-71.4%。     

沉淀-气浮组合工艺处理低浊高藻水试验研究

针对北方地区地表水夏天高藻冬天低温低浊的水质特点,采用沉淀-气浮组合工艺进行了低浊高藻水净水效果的中试研究。通过试验,首先确定了混凝剂PAFC投加量4.5mg/L、进水流量0.6m~3/h和回流比8%的试验条件。在此试验条件下,沉淀-气浮组合工艺的平均出水浊度为0.75NTU,去除率达95.2%;出水的颗粒数总量4 800个/mL,去除率达95.9%,且对不同粒径区间颗粒数去除效果基本一致;出水COD_(Mn)为3.95mg/L,去除率为41.3%,出水藻类数量270万~900万个/L,去除率达96%;臭味物质2-MIB和GSM的含量均小于6×10~(-6) mg/L,低于国标参考值。试验结果表明,沉淀-气浮组合工艺对浊度、颗粒数、藻类、臭味物质等去除率较高,对CODMn有一定的去除效果,低浊高藻水适合采用沉淀-气浮组合工艺进行处理。     

PPC预氧化和超滤协同处理引黄水库高藻水

采用高锰酸盐复合药剂(PPC)预氧化—混凝—沉淀—超滤组合工艺处理黄河下游引黄水库夏秋季节高藻水。工艺优化试验结果表明:当处理高藻水时,聚氯化铝最佳投加量为4mg/L,PPC最佳投加量为0.6mg/L。进行了混凝—沉淀—超滤和PPC预氧化—混凝—沉淀—超滤工艺中试比较,结果表明:两种工艺均能将出水浊度控制在0.1NTU以下;投加0.6mg/LPPC能使组合工艺对原水UV254和藻类的平均去除率分别提高10%和28%。将PPC预氧化技术和超滤技术联用,具有协同除污染作用,降低进入膜表面的污染负荷,缓解膜污染。     

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。     

Call for Papers

正As the eldest and most distributed professional journal of water industry,Water Wastewater Engineering(W WE)gained very wide acceptance from the colleagues working in this field in this country since start publication in 1964.Now it is administrated by the Ministry of Construction of the People’s Republic of China and sponsored by the China Civil Engineering Society etc.     

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.     

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.     

Impacts of Microcystis on algal biodiversity and use of new technology to remove Microcystis and dissolved nutrients

Cyanobacteria often dominate eutrophic lakes, outcompeting green algae that are required by fish and zooplankton. This study was undertaken to ascertain the impact of the cyanobacterium, Microcystis, on algal biodiversity. Under laboratory conditions, we found that the presence of Microcystis decreased phyla richness by 58%, phyla evenness by 47%, genera richness by 66% and genera evenness by 51%. Analysis by mixed anova s demonstrated a significant interaction between treatment and time and confirmed a significant reduction in richness and evenness of phyla and genera. We also conducted a phosphate restriction assay on the algae in Mason Lake (Irvine, CA, USA) and found that the threshold needed for algal growth there was 0.02 mg L^?1 PO₄. A pilot study was then conducted to test the effectiveness of the Blue Pro? water treatment facility in removal of this colonial organism from Mason Lake, in addition to removal of dissolved nutrients required for its growth. We measured a 97% reduction in Microcystis cells, a 72% reduction in chlorophyll‐a, and a 96% reduction in phosphate after just one 10 min cycle through the unit. Our study demonstrated that removal of Microcystis colonies may allow green algae to increase in numbers. This may improve algal biodiversity, which will benefit zooplankton and fishes.     

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。     

SPATIAL AND TEMPORAL WATER QUALITY VARIABILITY IN AQUATIC HABITATS OF A CULTIVATED FLOODPLAIN

The floodplains of lowland rivers contain diverse aquatic habitats that provide valuable ecosystem services but are perturbed when intensively cultivated. Hydrologic, water chemistry and biological (fish) conditions in five aquatic habitats along the Coldwater River, Mississippi, were measured for more than 4 years: the river, two severed meanders that functioned as backwaters, a managed wetland and an ephemeral channel draining cultivated fields. Off‐channel habitats were connected to downstream regions 0.10% to 32% of the dry season and 24% to 67% of the wet season. The median temperatures for the five monitored sites ranged from 18°C to 23°C, the median total solids concentration for all sites was 135 mg L^?1, the median total phosphorus was 0.29 mg L^?1 and the median total nitrogen was 1.56 mg L^?1. Chemical and physical water quality displayed strong seasonal differences between the wet winter/spring and the dry summer/fall periods so that temporal variation consisted of gradual seasonal trends superimposed on strong diurnal variations. All off‐channel habitats exhibited periods of hypoxia and temperatures >30°C during the dry season. Between‐site gradients of water and habitat quality were strongly coupled to water depth and runoff loading. The rehabilitation of one backwater by increasing water depth and diverting agricultural runoff was associated with improved water quality and fish species richness relative to an adjacent untreated backwater. The diversion of polluted runoff and the use of water control structures to maintain greater water depth were observed to be effective management tools, but the former reduces the water supply to habitats that tend to dry up and the latter reduces connectivity. Published in 2011 by John Wiley & Sons, Ltd.     

簸箕李引黄灌区水沙分布及优化调度的经验

灌区利用水沙观测所取得的资料和试验数据，运用水沙运动力学理论，总结分析和揭示了灌区水沙分布的规律和特点。在此基础上，结合灌区的实际运行情况，围绕减少骨干渠道的淤积进行探讨、研究，进而，优化水沙调度方案。该方案实施后，骨干渠道减旅伴效果明显，取得了成功的经验。     

小湾水库大坝防渗面板及其裂缝的加固处理

小湾水库大坝防渗面板整体抗渗性能差,且存在多条裂缝,通过对面板钢丝网喷涂丙乳砂浆加固处理及其裂缝修补,大坝渗漏量明显减少,且左岸上灌浆廊道内及大坝下游坝面92～93 m高程下廊道入口处原有小股射流全部消失.     

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。