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831.
832.
2种人工湿地的水力停留时间及净化效果 总被引:2,自引:0,他引:2
以复合垂直流人工湿地(IVCW)和水平潜流人工湿地(HSCW)为研究对象,研究了2种湿地运行的季节性最佳水力停留时间(HRT)参数,并监测了2种湿地在最佳HRT参数下运行时对污水的净化效果。结果显示:(1)在IVCW中,最佳HRT在春、秋季为8~10 h;夏季为6 h;冬季为12 h。在HSCW中,最佳HRT在春、秋季为10~12 h;夏季为6~8h;冬季为24~36 h。(2)2种湿地对COD的去除率均无显著的季节性差异;湿地进水中NH4+-N/TN比值与TN去除率显著负相关;不同季节下IVCW对TN的去除效果均高于HSCW。(3)水温对TN、TP去除率的影响在IVCW中比HSCW中的明显;水温高时,2种湿地中的TN去除率较高,IVCW中的TP去除率也较高,但HSCW中的TP去除率则较低,它们间均未达到显著的相关性。 相似文献
833.
以绿色环保涂料的基本组成元素为出发点,深入研究了绿色环保涂料的优势,分析了绿色环保涂料与人体健康的关系,并进一步探讨了绿色环保涂料的主要发展趋势,从而为我国研发对人体健康无害的涂料,促进涂料业的可持续发展,奠定了理论基础。 相似文献
834.
3H和99Tc在黄土中的迁移特性比较 总被引:1,自引:0,他引:1
3H和99Tc是低中放废物处置中2个重要的核素,在处置场的安全评价中十分重要.由于介质对3H和99Tc的吸附较弱,常忽略其滞留性,并用3H标定地下水的流速.野外实验表明:在包气带中,黄土对99Tc的吸附大于3H;在含水层中,黄土对3H迁移的影响大于99Tc.本文根据实验数据,采用非平衡吸附模式NESOR程序分别模拟了3H和99Tc在黄土包气带和含水层中的迁移过程.模拟结果表明:99Tc在黄土包气带中的分配系数范围为0.05~0.055mL/g;3H在黄土含水层中分配系数为0.116mL/g,该参数是黄土对3H和99Tc综合影响的结果,其滞留机理尚待研究. 相似文献
835.
Quantifying the Effect of Ecological Restoration on Soil Erosion in China’s Loess Plateau Region: An Application of the MMF Approach 总被引:5,自引:0,他引:5
Changbin Li Jiaguo Qi Zhaodong Feng Runsheng Yin Biyun Guo Feng Zhang Songbing Zou 《Environmental management》2010,45(3):476-487
Land degradation due to erosion is one of the most serious environmental problems in China. To reduce land degradation, the
government has taken a number of conservation and restoration measures, including the Sloping Land Conversion Program (SLCP),
which was launched in 1999. A logical question is whether these measures have reduced soil erosion at the regional level.
The objective of this article is to answer this question by assessing soil erosion dynamics in the Zuli River basin in the
Loess Plateau of China from 1999 to 2006. The MMF (Morgan, Morgan and Finney) model was used to simulate changes in runoff
and soil erosion over the period of time during which ecological restoration projects were implemented. Some model variables
were derived from remotely sensed images to provide improved land surface representation. With an overall accuracy rate of
0.67, our simulations show that increased ground vegetation cover, especially in forestlands and grasslands, has reduced soil
erosion by 38.8% on average from 1999 to 2006. During the same time period, however, the change in rainfall pattern has caused
a 13.1% ± 4.3% increase in soil erosion, resulting in a net 25.7% ± 8.5% reduction in soil erosion. This suggests that China’s
various ecological restoration efforts have been effective in reducing soil loss. 相似文献
836.
Deji Reservoir is situated in the middle of Taiwan on the upstream catchment of the Dajia stream with an area of over 60,160 ha. The embankment stands 180 m high and is the tallest concrete arch dam in Taiwan. This dam stores 1.7 billion cubic meters of valid volume water. It provides over 370 million kilowatt-hours of electricity annually. It is also an important facility for operating flood control, hydroelectricity, irrigation, public water supply, etc. Seventy-two percent of the terrain is at 2,000- to 3,000-m altitude, and 5.2% is above 3,200-m altitude. More than 59% of the area is covered with steep topography of 55% slope. Only 7.9% of the area is shown with gentle slopes of less than 30% slope, which are located among the two banks of main streams with the altitudes ranging from 1,500 to 2,500 m. Most of the gentle slopes are used for temperate zone fruit, vegetable, and tea plantations. This land-use immediately adjoins a reservoir catchment region, resulting in an enormous impact on the mountainous environment. This study reviewed human-developed land-use area to properly address and evaluate norms for mitigating the impacts on the reservoir. The initial investigation brought up the parameters of gradient, slope movement types and processes, distance to the reservoir, location of developed area and distance with the farm road, etc. Local investigation and global information system technology were conducted in this research. We focused on segregating the terrain types of indisposed land-use. A different land-use management strategy is also analyzed. 相似文献
837.
为解决工程裸露边坡对环境的影响,在生态防护工程中引入防冲刷基材(PEB)生态护坡技术,并介绍其主要功能特点和详细实施过程,结合河南燕山水库植被护坡工程实施后植物生长、浅层防护和水土保持的监测结果,对该技术进行了全面评析。结果表明,该技术在经济、植被生长适应性、抗冲刷性方面均表现出独特的效果和优势,能较快地恢复边坡原有生态效果。该技术在类似边坡的处理上可以广泛应用。 相似文献
838.
Rong Li Jing Wang Ailing Gu Yan Xu Jing Guo Jiafu Pan Yanhong Zeng Yuanlin Ma Canquan Zhou Yanwen Xu 《黑龙江环境通报》2021,41(6):681-689
839.
以乙醇为溶析剂,通过过滤—中和—蒸馏浓缩—溶析结晶等工序,从白炭黑废母液中回收硫酸钠。考察了硫酸钠回收效果的影响因素,并进行了热能消耗和处理成本的分析。实验结果表明:乙醇的加入量对硫酸钠溶解度和蒸馏浓缩过程有着显著影响;在蒸馏醇水比(乙醇与中性废母液的体积比)为0.27,浓缩废母液中硫酸钠质量浓度为69.27 g/L,溶析醇水比(乙醇与浓缩废母液的体积比)为1的最佳工艺条件下,白炭黑废母液中硫酸钠的一次回收率可达69.94%,硫酸钠产品的纯度达到97.3%。 相似文献
840.
Koudenoukpo Zinsou Cosme Odountan Olaniran Hamed Guo Chuanbo Céréghino Regis Chikou Antoine Park Young-Seuk 《Environmental science and pollution research international》2023,30(5):11893-11912
Environmental Science and Pollution Research - Rivers are dynamic systems in complex interactions with their surrounding environments. Reliable and fast interpretation of water quality is therefore... 相似文献