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排序方式: 共有136条查询结果,搜索用时 390 毫秒
91.
92.
我国城市生活垃圾最主要的处理方法是生态填埋。而最关键的是其防渗层的研究。讨论了用HAS土壤固化剂固化粉砂土,结果表明开发出的防渗材料拥有良好的性能。低廉的价格,并能消纳一定量的工业废渣。可用于各种固体废物堆放场及作为路基材料等。 相似文献
93.
城市生活垃圾卫生填埋是当今世界上使用最广的垃圾处理方式.从垃圾的收集,垃圾分拣,以及良好的填埋场设计及施工是保证其正常运转的先决条件.国外填埋技术的运用和研究起步较早,在各方面理论和实践已经相当成熟.中国进行垃圾填埋处置应在立足本国国情和实际情况的基础上,积极学习和引进国外成果,建立起自己的一整套规范,设计出经济、合理的垃圾回收、处理系统,以达到经济、社会、环境效益的统一.在分析了垃圾填埋场渗滤波的来源、渗滤液中污染物的特点及其变化规律,渗滤液量的计算,以及控制垃圾填埋场渗滤液的方法以后.围绕垃圾填埋场的污染特点提出了一些建议. 相似文献
94.
T.C. Winter J.S. Eaton G.E. Likens 《Journal of the American Water Resources Association》1989,25(5):991-1008
ABSTRACT: Measured stream discharge plus calculated ground water discharge (total measured runoff) were compared with runoff calculated by the unit-runoff method for the two largest watersheds of Mirror Lake for 1981–1983. Runoff calculated by the unit-runoff method, using Hubbard Brook watershed 3 as the index watershed, was greater than the total measured runoff into Mirror Lake during periods of high flow and slightly less than the total measured runoff into Mirror Lake during periods of low flow. Annual calculated unit runoff was 17 to 37 percent greater than total measured runoff. Differences in monthly runoff are far greater, ranging from 0 to greater than 100 percent. For high flows the calculated unit runoff is about 2 times greater than total measured runoff. For low flows the northwest basin of Mirror Lake has the greatest ground water contribution compared to the other two basins. In contrast, Hubbard Brook watershed 3 has the least ground water contribution. 相似文献
95.
F Douglas Shields Donald H. Gray 《Journal of the American Water Resources Association》1992,28(5):917-931
he influence of woody vegetation on the reliability of a sandy levee was investigated using field data in seepage and slope stability analyses. Field data were collected from selected sites within a 10-km segment of a channel levee on the Sacramento River near Elkhorn, California. Root architecture and distribution were determined using the profile-wall method in which root cross sections were exposed in the vertical wall of an excavated trench. Transects running both parallel and perpendicular to the crest of the levee were excavated at six sites. Each site was dominated by different plant species: five sites were adjacent to trees or woody shrubs, while one supported only herbaceous growth. Lateral plant roots were primarily restricted to, and modified, the near-surface soil horizons to a depth of approximately 1 meter. Root area ratios (RARs) did not exceed 2.02 percent and generally decreased exponentially with depth. At depths greater than 20 cm, mean RARs for sites dominated by wood species were not significantly different from the mean RAB for the herbaceous site. No open voids clearly attributable to plant roots were observed. Roots reinforced the levee soil and increased shear resistance in a measurable manner. Infinite slope and circular arc stability analyses were performed on the landward and riverward slopes under different hydraulic loading conditions. Infinite slope analyses indicated increasing root area ratio from 0.01 percent to 1 percent increased the factor of safety from less than one to more than seven. Circular arc analyses indicated that even the lower measured root concentrations sufficed to increase safety factors for arcs with maximum depths of about 1 m from less than one to about 1.2. Our findings suggest that allowing woody shrubs and small trees on levees would provide environmental benefits and would enhance structural integrity without the hazards associated with large trees such as wind-throwing. 相似文献
96.
97.
Craig B. Boroughs Steven R. Abt 《Journal of the American Water Resources Association》2003,39(6):1457-1464
ABSTRACT: A reach of the Pecos River, located in eastern New Mexico, was examined to evaluate losses of river flows due to evaporation, seepage, and transpiration. An accurate assessment of the water losses along this reach is critical for determining how water rights are adjudicated for water users in the Pecos basin and interstate compact accounting. Water losses significantly impact flows through critical habitat for species protected under the Endangered Species Act. Daily losses of river flows were analyzed for the study reach that extends from immediately below the Pecos River confluence with Taiban Creek to the United States Geological Survey (USGS) gage near Acme. The analysis was completed with consideration for other processes including flood wave travel times and attenuation along with stream bank storage and returns. The analysis was completed using daily stream flow data from USGS gages located along the study reach. Empirical seasonal functions were developed to relate flow loss to the flow rate in the river. The functions were ultimately developed to provide a method for comparing the effects of different river flows on the available water supply. 相似文献
98.
分层填料土地毛管渗滤系统处理生活污水的研究 总被引:3,自引:0,他引:3
研究了煤渣与土壤分层装填的土地毛管渗滤系统处理生活污水的效果;该系统未种植物前的运行初期,进水溶解氧浓度的增加可促进好氧微生物的生长繁殖,使其较快处于稳定期;在系统运行稳定后,在装置表面种植了植物,进水溶解氧浓度的减少对系统去除污染物效果的影响不明显;在出水达到国家二级排放标准的情况下,该系统所能承受的最高水力负荷为0.2m/d,与常规的纯土壤地下渗滤系统运行水力负荷仅能<0.05m/d相比,提高了单位面积处理污水的能力,节省了占地面积。 相似文献
99.
为探讨注胶方法修复井下注采管柱螺纹接头缝隙的可行性,采用计算流体动力学欧拉-欧拉多相流方法构建胶液在注采管柱接头缝隙内的渗流流动数值仿真模型,模拟注胶压力驱动下修复胶液在管柱接头螺纹缝隙内的渗流过程,通过多工况条件下胶液在螺纹缝隙内的渗流数值模拟,研究注胶压力、胶液密度和螺纹失效缝隙对胶液渗流过程的影响。结果表明:基于欧拉-欧拉多相流的数值模型可有效预测胶液在管柱接头缝隙内的流动;胶液在狭缝内的渗流深度与注胶压力呈正比;胶液渗流深度与胶液密度呈反比;胶液渗流深度与螺纹缝隙尺寸呈正比。 相似文献
100.
不同草皮缓冲带对径流污染物的去除效果试验研究 总被引:12,自引:0,他引:12
选择上海地区常见的5种草皮植被,利用自行设计的试验装置构建草皮缓冲带,模拟上海地区农业面源污染和降雨特征,进行缓冲带污染物净化效果试验研究。结果表明,草皮的存在明显提高缓冲带对污染物的净化效果,并且能增强缓冲带土壤的渗透能力;百慕大缓冲带对径流SS的截留能力最强,平均去除率达到71.86%;草皮缓冲带对渗流水营养物质的净化效果明显高于径流,渗流水TN、TP平均去除率以白花三叶草最高,分别为58.27%和60.49%;综合考虑降雨特征和污染物净化效果等因素,百慕大、白花三叶草和高羊茅等3种草皮,可以作为上海地区缓冲带草皮植被的优先选择种类。 相似文献