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Du S.,Beijing Novel Environmental Protection Co. | Du S.,China University of Mining and Technology | Jin J.,Beijing Novel Environmental Protection Co. | Mou Z.,Tsinghua University | And 3 more authors.
Huanjing Kexue Xuebao/Acta Scientiae Circumstantiae | Year: 2011

Semi-aerobic landfilling is becoming the main technology to solve the solid waste pollution problem in some medium and small cities in China because of land resource limitation and the large amount of garbage. In this technology, the amount of air which enters the landfill site has great impact on the generation and composition of landfill gas (LFG). We set up pilot plants to simulate semi-aerobic landfill technology at the Zhuozhou municipal solid waste landfill site. Three different diameters of aeration conduits, DN100, DN150 and DN200(100mm, 150mm and 200mm) were connected to the leachate drainage pipe. The concentration of gases in the LFG was monitored for 10 weeks continuously. The results show that the concentration and the tendency of O2 in LFG coming from the plant with the DN100 aeration conduit are much higher than that from the other two plants. The greenhouse gases CH4 and CO2 have been controlled more effectively in this plant. Through aerothermodynamics calculations, we can see the amount of gas coming from the aeration conduits DN100, DN150 and DN200 are in the proportion 2:3:4. Since the amount of gas entering the drainage pipe is of the same level, more air is transported into the landfill from the DN100 aeration conduit than in the other two situations. Source

Shen Z.,Beijing Normal University | Gong Y.,Beijing Normal University | Li Y.,Beijing Guohuan Tsinghua Environmental Engineering Design and Research Institute | Liu R.,Beijing Normal University
Catena | Year: 2010

Experimental plots were constructed in the Zhangjiachong Watershed of the Three Gorges Reservoir Area to evaluate soil erosion of traditional slope land farming and effects of soil conservation measures. Surface runoff and sediment from the watershed and each plot were collected and measured during 2004-2007. Field investigations indicated that hedgerows were the best for soil erosion control, followed by stone dike terraces and soil dike terraces. The Water Erosion Prediction Project (WEPP) model was used to simulate erosion of annual and rainfall events both at the watershed and plot levels. The low deviation, high coefficient of determination and model efficiency values for the simulations indicated that the WEPP model was a suitable model. The soil erosion rate distribution was modeled to determine where serious erosion would occur during rainfall events in the Zhangjiachong Watershed and so control measures can be taken. © 2010 Elsevier B.V. All rights reserved. Source

Li W.,Tsinghua University | Zhang H.T.,Tsinghua University | Zhu Y.,Zhejiang University | Liang Z.W.,Zhejiang University | And 4 more authors.
Journal of Environmental Informatics | Year: 2015

Characterizing the spatiotemporal patterns of water bodies is an important environmental issue in the management and protection of water resources. The primary objective of this study was to assess the spatiotemporal characteristics of environmental monitoring data from Lake Taihu to improve water pollution control practices. A methodologically systematic application of a self-organizing map (SOM) was utilized for data mining in the northern part of Lake Taihu, China. The monitoring data set contained 14 variables from eight monitoring stations during the period 2000-2006. The SOM classified the data set into 10 clusters displaying a markedly different pattern. We determined the spatiotemporal distribution of water quality based on the data frequency at each station monitored monthly in the study area. Based on the SOM analysis results, we suggest that the government should increase the number of monitoring points in the region. Given the relatively poor water quality in the region, unnecessary points should be decreased and different control measures should be implemented during different seasons. The results of this study could assist lake managers in developing suitable strategies and determining priorities for water pollution control and effective water resource management. © 2015 ISEIS All rights reserved. Source

Wang Y.,Beijing Guohuan Tsinghua Environmental Engineering Design and Research Institute | Zhang H.,Tsinghua University | Zhu M.,Tsinghua University | Chen R.,The Second Municipal Wastewater Treatment Plant of Taiyuan City | And 2 more authors.
Chinese Journal of Environmental Engineering | Year: 2013

The horizontal subsurface flow constructed wetlands (SFCW) were built for advanced treatment of the tailwater with high-nitrogen low-carbon from a municipal sewage treatment plant in Taiyuan. The results showed that it spent two months from the start period to the stable operation period. In the stable operation period, the effluent of the wetland system achieved the IV level of GB 3838-2002, excepted TN. And TN achieved the 1A level standard of GB 18918-2002. Wetland system effluent can be reused for the waterscape. Every pollutant removal efficiency of constructed wetland system was bed 3> bed 2>bed 1.In this system, the impact of the filler was greater than that of the plants on the treatment of pollutants. The optimal packing order was the zeolite, the gravel and the slag. And the optimal plant planting order was reed, cattail, canna, yellow iris and reeds. Source

Gao L.,Tsinghua University | Zhang H.,Tsinghua University | Fan J.,University of Science and Technology Beijing | Zhou B.,University of Science and Technology Beijing | And 2 more authors.
Chinese Journal of Environmental Engineering | Year: 2013

The chemical inhibit test on chlorella was studied. Chlorella was the dominant alga in the landscape supplied with reclaimed water. The experimental results showed that the growth of chlorella was inhibited by dosing different concentrations of EMA, BSE and isothiazolinone. EMA could barely inhibit chlorella's growth and presented to be low-promoting and high-repressing. The inhibition rate of EMA was only 31%. BSE could significantly inhibit the growth of chlorella in a long period without relapse. When the dosing concentration was 1 mg/L, BSE could restrain the algal growth; when the dosage reached 10 mg/L, BSE could kill chlorella. Isothiazolinone had a great effect on algal control, and it could kill chlorella at 5 mg/L without relapse. Source

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