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201.
202.
Kazuo Kamura Yu Hara Bulent Inanc Masato Yamada Yuzo Inoue Yusaku Ono 《Journal of Material Cycles and Waste Management》2005,7(2):66-70
It is always possible for impermeable layers to exist in landfills. When they do, the properties of the solution at the exit of the leachate-collection system might not accurately reflect the overall properties of the landfill. This study examines whether resistivity monitoring is effective for determining the influence of impermeable layers on the leachate. The test cell used in this study was filled with waste made up mainly of incinerator ash and shredded incombustible material. Three lines of resistivity sensors were laid in the uppermost layer of the fill. A resistivity profile was recorded periodically from each of these lines. The water-table level and leachate properties were measured concurrently. Leachate conductivity was mainly controlled by concentrations of the main ions, and it correlated inversely to variations in resistivity. Temporal changes in the resistivity of the fills are an excellent means of assessing the leaching in fills. Monitoring the properties of leachate, combined with resistivity profiling, is extremely useful for interpreting the temporal changes of properties in landfills containing impermeable layers. 相似文献
203.
论高职高专英语教学改革——我院英语分级教学探索 总被引:1,自引:0,他引:1
根据目前我院英语教学状况,英语公共课有必要改革"单一目标"的教学模式,采用多目标个性化分层教学模式,提高学生英语素质.文中具体探讨了多目标个性化分级教学模式的内涵、实施的前提条件、依据及策略. 相似文献
204.
沉水植物对富营养化水体的净化效果研究 总被引:4,自引:0,他引:4
通过建立小型围隔区,研究了沉水植物对富营养化水体中氮、磷等污染物的净化效果,以及对底泥中磷含量的影响.结果表明:(1)在放养沉水植物的围隔水体中各种营养盐浓度明显低于对照围隔;(2)沉水植物对磷的吸收能够有效地保持底泥中磷的含量,而在对照围隔中的底泥中磷元素含量却不断增加;(3)经50天后,水体中TN、NH4 -N、TP、PO43--P和CODMn平均去除率分别为36.3%、70.5%、54.6%、65.4%和43.1%. 相似文献
205.
魏育 《中国环境管理干部学院学报》2005,15(3):104-106
采用化学法自动控制处理含铬和含镍电镀废水,选择合适的化学药剂和pH、ORP控制参数,连续式处理电镀废水.运行结果表明:该工艺简单、处理效果良好、运行稳定、可操作性好、运行成本适中、能很好的适应水质的波动,处理后的水质完全符合排放标准. 相似文献
206.
Use of Microbial Community to Evaluate Performance of a Wetland System in Treating Pb/Zn Mine Drainage 总被引:2,自引:0,他引:2
The performance of a wetland system in treating lead (Pb)/zinc (Zn) mine drainage was evaluated by using the polyurethane
foam unit (PFU) microbial community (method), which has been adopted by China as a standardized procedure for monitoring water
quality. The wetland system consisted of four cells with three dominant plants: Typha latifolia, Phragmites australis and Paspalum distichum. Physicochemical characteristics [pH, EC, content of total suspended solid (TSS) and metals (Pb, Zn, Cd, and Cu)] and PFU
microbial community in water samples had been investigated from seven sampling sites. The results indicated that the concentrations
of Pb, Zn, Cd, Cu, and TSS in the mine drainage were gradually reduced from the inlet to the outlet of the wetland system
and 99%, 98%, 75%, 83%, and 68% of these metals and TSS respectively, had been reduced in concentration after the drainage
passed through the wetland system. A total of 105 protozoan species were identified, the number of protozoa species and the
diversity index (DI) gradually increased, while the heterotrophic index (HI) gradually decreased from the inlet to the outlet
of the wetland system. The results indicated that DI, HI, and total number species of protozoa could be used as biological
indicators indicating the improvement of water quality. 相似文献
207.
Water use efficiency (WUE) is an important ecophysiological characteristic of plants, especially in semiarid and arid regions. At the scale of community or ecosystem, WUE is difficult to quantify because the amount of water used per unit dry mass production is a function of microclimatic variables and species composition. In this study, we analyzed corrected intrinsic water use efficiency (IWUE(s)) of grass and shrub species along the western segment of the Northeast China Transect (NECT) and the relationship between IWUE(s) and mean annual rainfall, habitat degradation status, vegetation type, and plant functional type (C3 versus C4) at 22 survey sites. Site intrinsic water use efficiency (IWUE(v)) and its relationship with the aforementioned site variables were analyzed based on species frequencies at each site. First, it was concluded that photosynthetic pathway played a very important role in determining species IWUE(s). Mean IWUE(s) for C4 species was approximately double that of C3 species. Second, mean annual rainfall, vegetation type, and site degradation status significantly affected IWUE(s) (p < 0.01). Mean IWUE(s) at degraded sites was twice as high as that at nondegraded sites. The mean IWUE(s) for meadows was significantly higher than those for other vegetation types (p < 0.05). Third, the frequency of occurrence of C4 plants explained 36% of the variance in IWUE(v) across the survey sites. The mean frequency of C4 occurrence at degraded sites was more than double that at nondegraded sites. Consequently, mean IWUE(v) at degraded sites was more than double that at nondegraded sites. Dominant C4 species in saline-alkaline areas tended to have higher intrinsic WUE than dominant C4 species in sandy shrub communities. 相似文献
208.
209.
210.
Liu Sinuo Lei Yin Zhao Jinsong Yu Shuxia Wang Ling 《Environmental science and pollution research international》2021,28(3):2995-3007
Environmental Science and Pollution Research - Water conservation and soil retention are two essential regulating services that are closely related, and their relationship might produce synergies... 相似文献