人工湿地的构建与应用   总被引：8，自引：0，他引：8  

张清 《湿地科学》2011,9(4):373-379

论述了人工湿地污水处理技术的机制和优势,阐述了人工湿地的构建和污水处理研究进展,表明人工湿地的污水处理效率与污染物的种类和污染程度、人工湿地的类型、湿地植物种类、基质类型、水力停留时间和水力负荷等密切相关.在中国,典型人工湿地有3种类型,分别为垂直流人工湿地、潜流式人工湿地和表面流人工湿地,主要用于处理来自化粪池、养殖...  相似文献   

A laboratory study of the self sealing behaviour of a compacted sand–bentonite mixture     

《Geomechanics and Geoengineering》2013,8(1):73-85

Bricks made of compacted sand–bentonite mixture are considered as a possible engineered barrier to isolate high-level radioactive waste at great depth. This work is aimed at investigating some specific effects related to the presence of discontinuities at the contact between the bricks and the excavation wall. In order to do this, an experimental device was developed in the laboratory. The model is made up of a specially designed infiltration cylinder which allows the precise definition of a planar discontinuity between the compacted specimen (a sand–bentonite mixture made up of sand and Kunigel clay from Japan) and a metal wall. During hydration and subsequent specimen swelling, the planar wall is filled, resulting in a healing process. Three total pressure gauges placed along the wall allow a detailed observation of the increase in total stress against the wall. After different periods of swelling, the maximum resistance of the specimen–wall interface to pressure was tested by imposing a pressure increase through a porous stone placed at one end of the cylinder. It was found that the maximum pressure supported by the interface is a function of the initial thickness of the discontinuity and the initial density of the specimen. It was also found that the maximum sustainable pressure depends linearly on the elapsed time. These results are of interest for optimizing water infiltration procedures in either mock-up tests or real disposal systems. If the maximum sustainable pressure at the interface is known, it is possible either to ensure homogeneous hydration of a mass of bricks by respecting the maximum injection pressure limit or to accelerate hydration by forcing water paths along the discontinuities.  相似文献   

动静力排水固结法在淤泥质地基处理工程中的应用   总被引：3，自引：0，他引：3  

张丽娟  李彰明  韩江 《岩土力学》2009,30(2):567-571

以广州南沙泰山石化仓储区1期淤泥质地基处理工程为背景,介绍了采用动静力排水固结法处理促淤饱和软黏土地基的基本思想和工艺。该工程施工与现场实时监测相结合,利用孔隙水压力、土体分层沉降和载荷试验等检测指标对加固效果进行了监测和检测。工程实践表明,采取动力即低能量“少击多遍”的强夯施工工艺,辅以填土预压和设置竖向塑料排水板的静力方法来加固淤泥质地基,其效果明显,促淤地基的物理力学性能和抗变形性能显著提高,整体加固效果很好,工后各项指标完全达到或超过预期值。  相似文献   

核废物地质处置中热-水-应力耦合对迁移影响的三维有限元模拟   总被引：1，自引：0，他引：1  

张玉军 《岩土力学》2009,30(7):2126-2132

将所建立的热-水-应力-迁移耦合模型及开发的有限元程序,由二维分析拓展到三维分析,并从方法论研究的角度,以一个简单的核废物地质处置模型为算例,进行热-水-应力-迁移耦合过程的三维数值模拟,考察了近场的温度、饱和度、核素浓度、孔隙水压力、位移、正应力、流速等的分布与变化,认为计算结果符合规律,得出了若干结论：为了精确地模拟放射性核素迁移,就必须将温度场、渗流场、应力场和核素浓度场进行耦合分析;核废物埋存若干年后将在处置孔壁附近产生较高的压应力;缓冲层内各点的核素浓度达到相对稳定的时间要比温度和饱和度达到相对稳定的时间长得多。  相似文献   

特长隧道高压大流量突涌水治理施工和技术探讨     

魏树民 《岩土力学》2006,27(Z1):469-472

结合工程实例,介绍了长大隧道施工中高压大流量突涌水治理所采用的超前地质预报、突涌水的预防及帷幕注浆封堵等主要施工技术。并对岩溶发育富含水地区隧道工程的施工进行了分析和探讨,并提出了可行性施工方案。  相似文献   

CFC在中国高放废物处置库预选区地下水研究中的应用   总被引：1，自引：0，他引：1  

郭永海  王驹  王志明  刘淑芬  吕川河 《地球学报》2006,27(3):253-258

本文介绍了地下水测年的CFC方法及其原理,并将这种方法实际应用于我国高放废物处置库预选区——甘肃北山地区的水文地质研究,结果表明,研究区内沟谷洼地浅部地下水的CFC年龄在15~26a,基岩裂隙浅部地下水多为不含CFC的老水与含CFC的新水的混合水。在描述了确定混合比方法的基础上,根据样品CFC含量计算了研究区地下水的混合比。与氚相比,CFC是目前年轻地下水测年更好的工具,具有更多的优越性。  相似文献   

Biomass and estimated productivity of the benthic macrofauna in the New York Bight: A stressed coastal area     

Frank W. Steimle 《Estuarine, Coastal and Shelf Science》1985,21(4):539-554

Waste disposal in the apex of the New York Bight has resulted in the contamination of sediments by toxic chemicals and some alteration to the community composition of the benthic macrofauna. The significance of these alterations to other communities in the area, e.g. its fishery resources, has not been clearly demonstrated. This paper presents data on an extensive survey of the macrofauna biomass, that many fish and lobster feed on, in the waste disposal impacted areas of the apex, using samples from both 1973 and 1980–1982. Variable mean production to biomass (P:B) ratios were used to estimate secondary production from the biomass of each major taxon. The macrofaunal biomass (wet wt.) of most of the apex area impacted by waste disposal was relatively high, with a mean biomass of 127 g m^?2 for 1973 and 344 g m^?2 for 1980–1982. Estimated secondary production was also high, being 201 Kcal m^?2 year^?1 in 1973 and 383 Kcal m^?2 year^?1 in 1980–1982. These values suggest there has been no inhibition of at least biomass, as the values were similar to or greater than values found in other areas of the Bight with similar bathymetric characteristics.  相似文献   

Public Participation in Rural Environmental Governance around the Water Source of Xiqin Water Works in Fujian     

SU Shipeng  LI Xin  HUANG Ansheng  SUN Xiaoxia 《资源与生态学报(英文版)》2018,9(1):66-77

Public participation is an important way to improve the overall effect and social recognition of rural environmental governance in water source areas. Public participation makes environmental governance measures more targeted and effective, contributes to protecting the basic environmental rights of the public, and makes it easier to meet the livelihood needs of rural people. Public participation in rural environmental governance in water source areas is characterized by complex behavior and is dependent on public willingness to participate. Amongst other factors, it is subject to the combined influences of both internal (psychological cognition) and external (environmental regulation) conditions. This paper builds a theoretical framework for understanding public participation behavior in rural environmental governance, and uses it to analyze a case in the rural area surrounding the Xiqin Water Works in Fujian Province. In the case study, the public shows high willingness to participate, but low actual rates of participation. At the same time, the willingness of villagers to pay for the control of pollution from livestock and poultry breeding varies greatly from village to village, and there are also noticeable individual differences in public participation in the use of public collection points for rural household waste. We found that gender, understandings of environmental protection and perception of environmental regulation, play a key role in influencing the willingness of farmers to pay for the control of pollution from livestock and poultry breeding. Individual awareness of environmental protection, environmental protection facility conditions, and environmental service quality had a significant influence on public participation in the use of public collection points for rural household waste.  相似文献   

Fate of individual sewage disposal system wastewater within regolith in mountainous terrain     

Kathleen Dano  Eileen Poeter  Geoff Thyne 《Hydrogeology Journal》2008,16(4):691-699

In order to improve understanding of the fate of septic tank or individual sewage disposal system (ISDS) effluent in regolith overlying fractured-rock aquifers, effluent from an ISDS in such a setting was tracked via geophysical, hydrological, and geochemical methods. Under typical precipitation conditions, the effluent entered the fractured bedrock within 5 m of the boundary of the constructed infiltration area. During a period of unusually high spring recharge, the plume migrated between 50 and 100 m within the regolith before infiltrating the fractured bedrock. The chemical signature of the effluent is similar to that required to account for the decline in water quality, suggesting a causative relationship (as estimated from mass-balance models of the surface-water chemistry near the mouth of the basin). The elevated salt content of the effluent during periods of high natural recharge to the infiltration area correlates with elevated salt concentrations in surface and groundwater at the basin scale, suggesting that some of the effluent salt load may be stored in the unsaturated zone during dry periods and flushed during periods of elevated natural recharge.  相似文献   

The influence of an excavation damaged zone on the thermal-mechanical and hydro-mechanical behaviors of an underground excavation     

S. Kwon  W.J. Cho 《Engineering Geology》2008,101(3-4):110-123

In Korea, a reference disposal system, KRS, was proposed in 2006 after 10 years of research and development. In the KRS, the high-level radioactive waste repository is considered to be located in a crystalline rock likes granite. For a validation of the feasibility, safety, and stability of the KRS, an underground research tunnel, KURT was constructed in Nov. 2006. During the construction of KURT by a controlled blasting, the size and characteristics of an excavation damaged zone(EDZ) were investigated by in situ as well as laboratory tests. The possible influences of an EDZ around a tunnel on the thermal, hydraulic and mechanical behaviors of the near field were investigated by using hydro-mechanical and thermo-mechanical coupling analyses. From this study, it was found that the existence of an EDZ can influence the thermal, hydraulic, and mechanical behaviors of the near field and it was recommended that an EDZ should be considered as an important parameter during the design of underground repositories.  相似文献