改良UASB—MBR工艺在垃圾渗滤液处理中的应用

某垃圾焚烧发电厂渗滤液处理站设计规模为300m3/d,污水处理采用改良UASB(HUASB)—MBR工艺,污泥处理采用机械脱水—焚烧法,沼气回收发电。介绍了工程的设计情况,重点阐述HUASB反应器和MBR系统的工艺流程、设计参数,概括了该工程的设计特点以及保证系统稳定运行的相关措施,为该工艺在垃圾渗滤液处理的工程应用提供参考。     

小型生活垃圾填埋场渗滤液处理工程设计

小型生活垃圾填埋场渗滤液产量少、管理水平低,如何选用合适的渗滤液处理技术是一个令管理者困扰的问题.简要介绍了生活垃圾卫生填埋场渗滤液常用处理技术,结合工程实例,对采用矿化垃圾工艺处理渗滤液进行了探讨,并分析了该技术的特点.     

垃圾填埋场渗滤液处理工艺及过程控制

结合国内外垃圾渗滤液处理工程实例及多年工程实际经验,提出台州路桥区卫生垃圾填埋场渗滤液处理工程采用调节-氨吹脱-混凝沉淀-A~2/O组合工艺,处理出水水质达到<生活垃圾填埋污染控制标准>(GB 16889-1997)的二级标准后,排入氧化塘进一步氧化后排放.介绍了该渗滤液处理系统的工艺流程、处理效果及主体工艺的过程控制.     

垃圾填埋场渗滤液调节池设计容积初探

从影响渗滤液产生的主要因素出发,根据调节池设置的目的,对垃圾卫生填埋场渗滤液处理工程中调节池容积与处理规模的关系进行了剖析.提出了垃圾填埋场渗滤液处理工程中调节池容积需结合垃圾填埋场具体情况考虑,建议建于平原地区的垃圾填埋场,采用最大月日均发生量作为处理设施的设计规模.最后对调节池的配套使用条件予以分析论述,建议渗滤液处理采用物化与生化结合工艺,生化系统应采用生物膜法,并设渗滤液排放调节装置.     

新AB工艺在垃圾渗滤液处理领域的应用

垃圾渗滤液和厨余垃圾处理厂的沼液，含有极高浓度氨氮、总氮和有机污染物，采用常规硝化反硝化工艺，它们能耗高、碳源投加量大，运行成本居高不下。在脱氨技术日趋成熟的前提下，渗滤液(沼液)首先采用AB工艺的A段，去除绝大部分COD和SS,然后进行脱氨处理去除大部分氨氮，再进入生化处理系统。新AB工艺的应用处理效果更佳，可以大幅降低运行成本，实现低碳排放，在填埋场渗滤液、焚烧厂渗滤液、厨余厂沼液和垃圾转运站污水处理领域具有极高的应用价值。     

深圳市某焚烧发电厂污水处理站节能设计措施

深圳市某焚烧发电厂污水处理站渗滤液处理水量为1 450m~3/d,处理工艺采用"预处理+厌氧+膜生化反应器(MBR)+纳滤(NF)+反渗透(RO)"的组合工艺。出水满足《城市污水再生利用工业用水水质》中循环水补充水相关要求。在设计时从渗滤液处理系统的工艺选择、设备选型及运行方式、资源回收利用等方面进行节能设计,以期降低渗滤液处理成本,并为垃圾焚烧厂渗滤液处理系统的节能设计提供借鉴。     

CASS工艺处理垃圾渗滤液工程设计实例

简要介绍垃圾渗滤液的产生 ,着重对利用CASS工艺处理垃圾渗滤液的优点 ,设计和调试的经验、体会以及对渗滤液处理效果作了叙述。以实例证明CASS工艺处理垃圾渗滤液的可行性。     

生活垃圾填埋场渗滤液处理规模的探讨

研究了生活垃圾填埋场渗滤液产生的不同途径,以垃圾填埋过程及场外影响因素为研究对象,以入渗系数法为基础,提出了逐年平均法预测渗滤液产生量的公式,以此确定填埋场渗滤液处理系统的设计规模。在此基础上,结合工程实例,验证了预测方法的可靠性。     

UASB反应器在垃圾渗滤液处理中的应用

UASB厌氧反应器的出现,使得厌氧消化在近几年来成为废水生物处理的新技术。在垃圾渗滤液的处理中,也常采用厌氧污泥床工艺。通过对其工艺原理、反应器结构及在垃圾渗滤液处理中应用探讨,为类似污水处理设计提供参考。     

城市垃圾填埋场渗滤液处理工艺及其研究进展

垃圾渗滤液污染物浓度高 ,水质水量变化大 ,是国内外污水处理的难题。综述了垃圾渗滤液的生物、物理化学、土地和循环回灌处理法 ,分析了各种处理方法的特点 ,讨论了国内外渗滤液处理研究的进展 ,列举了我国几大垃圾填埋场渗滤液处理工艺。认为生物法与物理化学法结合将是未来渗滤液处理研究的主要方向。经济高效的脱氨氮方法能大大提高后续生物处理效率     

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.     

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。     

库水波动下库岸边坡地下水浸润线解析解及误差分析

解析法是库岸边坡地下水浸润线计算中便于实际应用的方法,但该方法须基于若干假定并对潜水运动基本方程线性化后才能求解。针对各假定和线性化过程建立不同的地下水渗流数学模型,用解析法和有限元法解答上述数学模型,分析各误差大小及其规律。结果表明：库岸垂直处理带来的误差要小于方程线性化处理和不考虑非饱和渗流带来的误差,而且它们都随渗透系数变大而减小;在三峡库区库水调度情况下,假定库水位等速变化带来的误差对大多岸坡而言可以忽略;计算库岸边坡地下水浸润线时,解析法只适用于水位变化幅度相比含水层厚度较小,且几何边界规则、岩土结构简单、岩土体渗透性较好时的情况。     

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.     

Changes in Summer Irrigated Crop Area and Water Use in Southeastern Turkey from 1993 to 2002: Implications for Current and Future Water Resources

Changes in summer irrigated cropland acreage and related water use are estimated from satellite remote sensing and ancillary data in semi-arid Southeastern Turkey where traditionally dry agricultural lands are being rapidly transformed into irrigated fields with the help of water from the Euphrates-Tigris Rivers. An image classification methodology based on thresholding of Landsat NDVI images from the peak summer period reveals that the total area of summer irrigated crops has increased three-fold (from 35,000 ha to over 100,000) in the Harran Plain between 1993 and 2002. Coupled analysis of annual irrigated crop area from remote sensing and potential evapotranspiration based estimates of irrigation water requirements for cotton indicate a corresponding increase in agricultural water use from about 370 million cubic meters to over one billion cubic meters, a volume in accordance with the state estimates. These estimates have important implications for understanding the rapid changes in current agricultural withdrawals in Southeastern Turkey and form a quantitative basis for exploring the changes in future water demands in the region. For example, expansion of irrigated lands have led to a steady decrease in potential evaporation due to increased roughness and decreased humidity deficit in the Harran Plain. Assuming that the changes in future evaporation conditions will be of similar nature, water use for irrigation is expected to decrease over 40 percent in future irrigation sites. Incorporating this decrease in overall planning of the irrigation projects currently under construction should lead to improved management, and by extension, sustainability of water resources in the region.     

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.     

Spatio‐temporal variation of gross CO2 and CH4 diffusive emissions from Australian reservoirs and natural aquatic ecosystems,and estimation of net reservoir emissions

Carbon dioxide (CO₂) and methane (CH₄) diffusive emissions were measured during two field surveys in Queensland and Tasmania, Australia, using the floating chamber method. Bubbling and degassing emissions in 2010 were estimated in Koombooloomba Dam reservoir using only inverted funnels and gas concentrations, respectively. A total of 14 reservoirs and 16 rivers and lakes were sampled from 2006 to 2010. Spatial variation was substantial within each water body, as well as between them. The main drivers of diffusive emission variation were physiographic region and climate, with a clear demarcation being observed between diffusive emissions from tropical Queensland and temperate Tasmania, and between the humid West Coast Range (Tasmania) and dry Central Plateau (Tasmania). Higher CO₂ and CH₄ diffusive emissions were observed during the dry season, when long water residence times would promote organic matter degradation. Estimated total gross emissions, including diffusive, bubbling and degassing emissions, for Koombooloomba Dam reservoir were about 1.5 × 10⁶ t CO₂eq km² per year, or 24 × 10⁶ t CO₂eq per year. This corresponds to a plant emission factor of 3.18 kg CO₂eq MWh^?1. Using an estimate of terrestrial emissions derived from literature data for the Tully River catchment area, rough estimated net emissions from the catchment area are about 44 kt CO₂eq per year, or 5.83 kg CO₂eq MWh^?1, which is in the lower range of the studied reservoirs.