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1.
采用陶粒、沸石、活性炭填料合理组合作为曝气生物滤池的填料对高校生活污水进行处理。研究了组合填料生物滤池生物膜的培养,不同水力负荷、容积负荷和气水比对污水处理效率的影响,以及该生物滤池对生活污水的处理效果。结果表明,采用组合填料生物滤池,接种挂膜培养周期为25d,在水力负荷为2.5m3/(m2·h),气水比3.5:1,组合填料生物滤池出水COD、BOD5、SS、NH3-N和色度平均值达到《城市污水再生利用城市杂用水水质》GB/T18920—2002水质要求。  相似文献   

2.
反冲洗是快滤池的一项关键技术,反冲洗的效果关系到滤床下一个周期的过滤效果.试验证明水淬渣-石英砂双层滤料采用气-水反冲洗在冲洗效果、减少冲洗时间、降低冲洗耗水量及避免混层等方面比单水反冲洗有优势.在工程实践中水淬渣石英砂双层滤料反冲洗选用水强度为5L/m2·s、气强度为10L/m2·s、冲洗历时4min合适.  相似文献   

3.
胍胶压裂返排液具有高黏度、难固液分离的特征。强化该类废液的固液分离效果是开展深度处理的前提,去除废液中泥砂、岩屑、胍胶残渣等颗粒物,可确保处理后水水质达到再利用要求。通过室内试验得出影响该类废液固液分离效率的主要因素,包括废液黏度、颗粒物密度、粒径及混凝效果,并就延时混凝技术强化固液分离效果进行了试验研究。采用延时混凝形成的絮体粒径较常规絮凝物增加0.7~1.8 mm,絮凝物沉淀速率由常规的18 mm/s增加至25 mm/s,该试验研究为胍胶压裂返排液处理设备优化设计提供了技术依据。  相似文献   

4.
生物接触氧化法处理生活污水   总被引:8,自引:0,他引:8  
在生物滤池处理生活污水的基础上发展一种利用生物膜处理废水的新方法─—生物接触氧化法。其中心处理构筑物是接触氧化池,池内装有多种填料。从监测结果分析,虽然处理后水质都符合国家排放标准,但BOD5的去除率比较低,只有69%,由于监测是在试运行刚结束进行的,如果一切运行正常,BOD5的去除率可达90%以上。生物接触氧化法是目前比较成熟的生化处理方法,对含有大量有机污染物的生活污水处理效果较好,且处理后的污水还可进行灌溉、建筑、冲洗等重复利用。  相似文献   

5.
生化技术在采油废水治理中的应用   总被引:6,自引:1,他引:6  
利用生化技术处理冀东油田的采油废水,在处理工艺流程中采用了悬浮、附着厌氧-好氧氧化池。与其他污水生化处理工艺相比,其不同之处是在池中同时存在悬浮污泥和固着生物膜,保持了很高的生物量,增强了设施耐冲击负荷的性能和处理能力。同时,池中还设置了可自由摆动的中密度弹性立体填料,池底设置了可变微孔曝气管。在曝气过程中,弹性立体填料对气泡有多层次的切割能力,可以提高充氧效率,污染物去除效果明显,对难降解的有机废水也有很好的处理效果。石油类去除率达到83%,COD去除率达到80%,出水水质达到了国家污水综合排放一级标准。  相似文献   

6.
常规的"沉降+过滤"方式用于三元复合驱采出水处理,聚合物或黏度对石油类和SS的高效去除有较大影响,处理思路应以脱稳降黏为主。文章探索了采用的"气浮沉降+生化氧化+高级氧化+二级过滤"工艺,达到石油类≤800 mg/L,SS≤350 mg/L,黏度≤12 mPa·s,PAM≤800 mg/L,使采出水处理稳定达到回注水要求,降低滤池冲洗难度,降低了固液分离难度,提高了工艺运行稳定性。对于采出水进一步开展膜深度处理,采出水实现回注低渗透层等具有重要意义。  相似文献   

7.
岩土工程施工中产生的废泥浆直接排放会对环境有很大危害。根据废泥浆特点、固液分离效率、分离成本以及对分离物的要求等,选择全自动隔膜式板框压滤机作为固液分离设备,介绍了其工作原理以及针对钻孔桩废泥浆压滤机的技术参数,分析了泥浆压滤过程中提高泥浆压滤效率的方法以及应注意的事项。用该型设备在现场进行了试验验证,取得了较好的固液分离效果,固液分离成本远低于传统外排处理成本。  相似文献   

8.
长庆低渗透油田废弃钻井液处理探讨   总被引:3,自引:1,他引:3  
通过对长庆低渗透油田废弃钻井液性能分析,确定了固液分离-固化一体化处理思路;研究了不同破胶剂体系、破胶剂加量、絮凝剂分子量等对固液分离及出水率的影响;处理结果表明:添加20%粘土同时加入6%固化剂时固化体针入度可降至0.5mm以下,达到强度要求,又可降低成本。现场试验证实固液分离析出水和固化体浸出液均达到GB8978-1996《污水综合排放标准》二级标准。  相似文献   

9.
以砾石为填料采用生物滤池法和以纤维束为填料采用生物接触氧化法,分别预处理沈抚灌渠污水。试验结果表明,在水力停留时间在3.5h,控制气水比分别为5:1和4:1的反应条件下,砾石填料对COD和NH3-N的平均去除率分别为53.9%和53.6%;纤维束软填料对COD和NH3-N的平均去除率分别为55.7%和47.7%。前者对COD和NH3-N的处理效果都达到了预定要求,而后者对NH3-N的处理效果没有达到要求。  相似文献   

10.
固液分离法处理废钻井液的实验研究   总被引:3,自引:1,他引:2  
废钻井液对环境的污染是一个难以解决的问题。针对塔里木油田的地质情况,使用固液分离法对部分废钻井液样品进行了实验研究工作。固液分离法采用两次处理工艺流程。即先经一级初步絮凝处理和强化离心分离,使大部分固相去除,然后对脱出的废液进行第二级絮凝处理后即可达到排放要求。实验结果表明:固液分离法能够将废钻井液分离成固-液两相,其液相能够达到排放要求,固相残渣对环境污染程度大幅度降低甚至无污染;若将此处理法同其它方法相结合,如坑内密封法、固化法等相结合会得到更满意的环保效果。  相似文献   

11.
Fire and logging in nutrient-poor temperate forests with certain ericaceous understory plants may convert the forests into heaths. The process of disturbance-induced heath formation is documented by using examples ofCalluna in western Europe,Kalmia in Newfoundland, andGaultheria (salal) in coastal British Columbia. In a cool, temperate climate, rapid vegetative growth ofCalluna, Kalmia, and salal following disturbance results in increasing organic accumulation (paludification), nutrient sequestration, soil acidification, and allelochemicals. These are thought to be the main reasons to conifer regeneration failure in disturbed habitats. If continuation in forest is a land-use objective, then temperate forests with an ericaceous understory should not be logged unless effective silvicultural methods are devised to control the ericaceous plants and restore forest regeneration. Preharvest vegetation control may be considered as an option. Failure to control the understory plants may lead to a long-term vegetation shift, from forest to heathland, particularly in nutrient-poor sites. Successful methods of controllingKalmia andGaultheria, however, have yet to be developed. While theKalmia- andGaultheria- dominated heathlands are undesirable in Canada and the Pacific Northwest, a wide range ofCalluna heathlands of western Europe are being conserved as natural and seminatural vegetation.  相似文献   

12.
Urban ecological systems: scientific foundations and a decade of progress   总被引:9,自引:0,他引:9  
Urban ecological studies, including focus on cities, suburbs, and exurbs, while having deep roots in the early to mid 20th century, have burgeoned in the last several decades. We use the state factor approach to highlight the role of important aspects of climate, substrate, organisms, relief, and time in differentiating urban from non-urban areas, and for determining heterogeneity within spatially extensive metropolitan areas. In addition to reviewing key findings relevant to each state factor, we note the emergence of tentative "urban syndromes" concerning soils, streams, wildlife and plants, and homogenization of certain ecosystem functions, such as soil organic carbon dynamics. We note the utility of the ecosystem approach, the human ecosystem framework, and watersheds as integrative tools to tie information about multiple state factors together. The organismal component of urban complexes includes the social organization of the human population, and we review key modes by which human populations within urban areas are differentiated, and how such differentiation affects environmentally relevant actions. Emerging syntheses in land change science and ecological urban design are also summarized. The multifaceted frameworks and the growing urban knowledge base do however identify some pressing research needs.  相似文献   

13.
Urban gardens are important sources of sustenance for communities with limited access to food. Hence, this study focuses on food production in gardens in the Toledo metropolitan area in Northwest Ohio. We administered surveys to 150 garden managers from November 2014 to February 2015 in our attempt to better understand how neighbourhood racial composition and poverty levels are related to staffing and voluntarism, food production and distribution, the development of infrastructure, and the adoption of sustainability practices in urban gardens. The results from 30 gardens are presented in this paper. We used Geographic Information Systems to map the gardens and overlay the map with 2010 census data so that we could conduct demographic analyses of the neighbourhoods in which the gardens were located. Though the gardens were small – two acres or less – up to 46 varieties of food were grown in a single garden. Gardens also operated on small budgets. Food from the gardens was gifted or shared with friends, family, and neighbourhood residents. Gardens in predominantly minority neighbourhoods tended to have fewer institutional partners, less garden infrastructure, and had adopted fewer sustainable practices than gardens in predominantly White neighbourhoods. Nonetheless, residents of predominantly minority and high-poverty neighbourhoods participated in garden activities and influenced garden operations. Volunteering and staffing were racialised and gendered.  相似文献   

14.
In water stressed regions, water managers are exploring new horizons that would help in long‐range streamflow forecasts. Oceanic‐atmospheric oscillations have been shown to influence streamflow variability. In this study, long‐lead time streamflow forecasts are made using a multiclass kernel‐based data‐driven support vector machine (SVM) model. The extended streamflow records based on tree ring reconstructions were used to provide a longer time series data. Reconstructed data were used from 1658 to 1952 and the instrumental record was used from 1953 to 2007. Reconstructions for oceanic‐atmospheric oscillations included the El Niño‐Southern Oscillation, Pacific Decadal Oscillation, Atlantic Multidecadal Oscillation, and North Atlantic Oscillation. Streamflow forecasts using all four oscillations were made with one‐year to five‐year lead times for 21 gages in the western United States. This is the first study that uses both instrumental and reconstructed data of oscillations in SVM model to improve streamflow forecast lead time. SVM model was able to provide “satisfactory” to “very good” forecasts with one‐ to five‐year lead time for the selected gages. The use of all the oscillation indices helped in achieving better predictability compared to using individual oscillations. The SVM modeling results are better when compared with multiple linear regression model forecasts. The findings are statistical in nature and are expected to be useful for long‐term water resources planning and management.  相似文献   

15.
Collisions with deer and other large animals are increasing, and the resulting economic costs and risks to public safety have made mitigation measures a priority for both city and wildlife managers. We created landscape models to describe and predict deer-vehicle collision (DVCs) within the City of Edmonton, Alberta. Models based on roadside characteristics revealed that DVCs occurred frequently where roadside vegetation was both denser and more diverse, and that DVCs were more likely to occur when the groomed width of roadside right-of-ways was smaller. No DVCs occurred where the width of the vegetation-free or manicured roadside buffer was greater than 40 m. Landscape-based models showed that DVCs were more likely in more heterogeneous landscapes where road densities were lower and speed limits were higher, and where non-forested vegetation such as farmland was in closer proximity to larger tracts of forest. These models can help wildlife and transportation managers to identify locations of high collision frequency for mitigation. Modifying certain landscape and roadside habitats can be an effective way to reduce deer-vehicle collisions.  相似文献   

16.
Manganese entering impounded water will undergo a cyclic transformation. Oxidation precipitates manganese from top waters. At the bottom of the lake, biological activity will render manganese soluble by both intracellular as well as extracellular activity. The study was made to demonstrate that biological reduction and transformation, organometallic complexation, together with the presence of carbon dioxide and the lowering of pH all have some effect on the solubility of manganese. Dissolved manganese may be brought back to top waters during the lake overturn and therefore deteriorates the water quality.  相似文献   

17.
ABSTRACT: Mathematical models for predicting watershed surface flow responses are available, most of which are elaborate nonlinear numerical surface and channel flow models linked with infiltration models. Such models may be used to make predictions for ungaged areas, assuming an acceptable fitting of the model to the topography and roughness of the real system. For some application purposes, these models are impractical because of their complexity and expensive computer solutions. A procedure is developed that uses a complex model of an ungaged area to derive a simpler parametric nonlinear system model for repetitious simulation with input sequences. The predicted flow outputs are obtained with the simpler model at significant savings of money and time. The procedures for constructing a complex kinematic model of a 40 acre (161,880 m2) reference watershed and deriving the simpler system model are outlined. The results of predictions from both models are compared with a selected set of measured events, all having essentially the same initial conditions. Peak discharges ranged from 3 to 118 ft3/sec (0.085 to 3.34 m3/sec), which includes the largest event of record. The inherent limitations of lumped systems models are demonstrated, including the bias caused by their inability to model infiltration losses after rainfall ceases. Computer costs and times for the models were compared. The derived simple model has a cost advantage when repeated use of a model is required. Such an applications hydrologic model has an engineering tradeoff of reduced accuracy, and lumping bias, but is more economical for certain design purposes.  相似文献   

18.
Water treatment residuals (WTR) can reduce runoff P loss and surface co-application of P-sources and WTR is a practical way of land applying the residuals. In a rainfall simulation study, we evaluated the effects of surface co-applied P-sources and an Al-WTR on runoff and leacheate bioavailable P (BAP) losses from a Florida sand. Four P-sources, namely poultry manure, Boca Raton biosolids (high water-soluble P), Pompano biosolids (moderate water-soluble P), and triple super phosphate (TSP) were surface applied at 56 and 224kgPha(-1) (by weight) to represent low and high soil P loads typical of P- and N-based amendments rates. The treatments further received surface applied WTR at 0 or 10gWTRkg(-1) soil. BAP loss masses were greater in leachate (16.4-536mg) than in runoff (0.91-46mg), but were reduced in runoff and leachate by surface applied WTR. Masses of total BAP lost in the presence of surface applied WTR were less than approximately 75% of BAP losses in the absence of WTR. Total BAP losses from each of the organic sources applied at N-based rates were not greater than P loss from TSP applied at a P-based rate. The BAP loss at the N-based rate of moderate water-soluble P-source (Pompano biosolids) was not greater than BAP losses at the P-based rates of other organic sources tested. The hazards of excess P from applying organic P-sources at N-based rates are not greater than observed at P-based rates of mineral fertilizer. Results suggest that management of the environmental P hazards associated with N-based rates of organic materials in Florida sands is possible by either applying P-sources with WTR or using a moderate water-soluble P-source.  相似文献   

19.
The SPARROW (SPAtially Referenced Regression on Watershed attributes) model was used to simulate annual phosphorus loads and concentrations in unmonitored stream reaches in California, U.S., and portions of Nevada and Oregon. The model was calibrated using de‐trended streamflow and phosphorus concentration data at 80 locations. The model explained 91% of the variability in loads and 51% of the variability in yields for a base year of 2002. Point sources, geological background, and cultivated land were significant sources. Variables used to explain delivery of phosphorus from land to water were precipitation and soil clay content. Aquatic loss of phosphorus was significant in streams of all sizes, with the greatest decay predicted in small‐ and intermediate‐sized streams. Geological sources, including volcanic rocks and shales, were the principal control on concentrations and loads in many regions. Some localized formations such as the Monterey shale of southern California are important sources of phosphorus and may contribute to elevated stream concentrations. Many of the larger point source facilities were located in downstream areas, near the ocean, and do not affect inland streams except for a few locations. Large areas of cultivated land result in phosphorus load increases, but do not necessarily increase the loads above those of geological background in some cases because of local hydrology, which limits the potential of phosphorus transport from land to streams.  相似文献   

20.
The interactions between humans, animals and the environment have shaped human values and ethics, not only the genes that we are made of. The animal rights movement challenges human beings to reconsider interactions between humans and other animals, and maybe connected to the environmental movement that begs us to recognize the fact that there are symbiotic relationships between humans and all other organisms. The first part of this paper looks at types of bioethics, the implications of autonomy and the value of being alive. Then the level of consciousness of these relationships are explored in survey results from Asia and the Pacific, especially in the 1993 International Bioethics Survey conducted in Australia, Hong Kong, India, Israel, Japan, New Zealand, The Philippines, Russia, Singapore and Thailand. Very few mentioned animal consciousness in the survey, but there were more biocentric comments in Australia and Japan; and more comments with the idea of harmony including humans in Thailand. Comparisons between questions and surveys will also be made, in an attempt to describe what people imagine animal consciousness to be, and whether this relates to human ethics of the relationships. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

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