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71.
研究了生化黄腐酸(BFA)对污染水体生物修复的强化作用。生化黄腐酸能提高水体中微生物活性,加快微生物对目标污染物的降解。在污染水体生物修复强化作用的试验中,投加生化黄腐酸,CODCr、NH3-N、TP和浊度的去除率分别增加了29.47%、20.61%、35%和19.86%,同时有利于水体DO的提升。  相似文献   
72.
In this paper, continuous production of hydrogen through fermentation with liquid swine manure as substrate was researched using a semi-continuously fed fermenter (8 L in total volume and 4 L in working volume). The pH and temperature for the fermenter were controlled at 5.3 +/- 0.1 and 35 +/- 1 degrees C, respectively, throughout the experiment. Three hydraulic retention times (16, 20, and 24 h) were investigated for their impact on the efficiency and performance of the fermenter in terms of hydrogen yields. The results indicate that hydraulic retention time (HRT) has a strong influence on the fermenter performance. An increasing HRT would increase the variation in hydrogen concentration in the offgas. To produce hydrogen with a fairly consistent concentration, the HRT of the fermenter should not exceed 16 h, which, however, did not appear to be short enough to control methanogenesis because the offgas still contained about 5% methane. When methane content in the offgas exceeded 2%, an inverse linear relationship between hydrogen and methane was observed with a correlation coefficient of 0.9699. To increase hydrogen content in the offgas, methane production has to be limited to below 2%. Also, keeping oxygen content in the fermenter below 1.5% would increase the hydrogen concentration to over 15%. The product to substrate ratio was found to be around 50% for the fermenter system studied, evidenced by the observation that for every 6 liters of manure fermented, 3 liters of pure hydrogen were produced, which was significant and encouraging.  相似文献   
73.
河口切变锋引起的滩槽泥沙交换效应   总被引:2,自引:1,他引:2  
切变锋是河口湾锋系中最为常见和最易观察到的锋面类型。本文对长江口的切变锋进行现场观察和滩,槽同步水文资料分析,简述了长江口切变锋发生的部分和基本特性,提出了切变锋引起的滩,槽泥沙呈现螺旋形交换形式等论点。  相似文献   
74.
环境资源的量化模型及估算指标体系   总被引:3,自引:0,他引:3  
本文依据区划环境标准,提出了环境资源的成本概念-环境成本。  相似文献   
75.
关于中国土地资源人口承载力问题的思考   总被引:4,自引:0,他引:4  
土地资源的人口承载力问题也就是生存空间问题,它关系到人类未来的生存与发展问题,历来受学术界的注目。20世纪70年代联合国粮农组织(FAO)曾主持了一项大型的发展中地区土地资源人口承载力问题的研究,80年代后期,中国科学院—国家计委自然资源综合考察委员会也主持了一项大型的中国土地资源生产能力及人口承载量研究。相应地还有一系列有关中国未来的生存与发展和人口承载力问题的探讨。本文从中国人地关系变化的角度介入这一讨论,分析中国远期的土地资源是否超载的问题。  相似文献   
76.
The concept of sustainable development has experienced great development and change at different levels of theoretical connotation and practical implementation since 1960s and 1970s when it was first proposed. People’s understanding of the relationship between economy, society, and environment has been continuously deepened over the years. When it came to the end of 2015, it is necessary to examine the results of the United Nations Millennium Development Goals on sustainable development, and at the same time, the post-2015 framework and guidance on sustainable development at the global level were to be made, including the ideas, action plans, key areas that would guide the global sustainable development. The 2030 Agenda for Sustainable Development has developed a 5P theoretical framework of being people-centered, global environmental security, sustained economic prosperity, social justice and harmony and partnership promotion, including a political declaration, 17 overarching goals and 169 specific targets, specific ways of implementation, as well as the follow-up. It is the road map to achieve global sustainable development and meet the requirements of the millennium development goals. This paper summarizes the understanding of the concept of sustainable development from its origin, its significant development, to the proposition and development of the 2030 Agenda for Sustainable Development, and its strategic impact on China.  相似文献   
77.
Western China has lagged a lot in terms of industrial structure and economic development,compared with the national average.And China announced its target of CO_2 emission reduction,i.e.by 2020,CO_2 emission per GDP will drop by40-45%compared with 2005.The target will be incorporated into China's long-term industrial planning.Against this background,this paper will make a comprehensive examination of the industrial development of Western China,aiming to discover a green and compatible way.First,we analyze the spatiotemporal evolution of regional industrial structure for the period 2000-2010.Second,we try to discover the industrial structure optimization path for Western China by employing the Vector Auto Regression model.Lastly,we try to provide some advice and suggestions for further industrial development in Western China.Our examination shows that further industrial development in Western China should pay full attention to resource conservation and recycling,and develop on a green and compatible path.  相似文献   
78.
A glasshouse pot experiment was conducted to study the effect of arbuscular mycorrhizal (AM) colonization by Glomus mosseae BEG167 on the yield and arsenate uptake of tomato plants in soil experimentally contaminated with five As levels (0, 25, 50, 75 and 150 mg kg(-1)). Mycorrhizal colonization (50-70% of root length) was little affected by As application and declined only in soil amended with 150 mg As kg(-1). Mycorrhizal colonization increased plant biomass at As application rates of 25, 50 and 75 mg kg(-1). Shoot As concentration increased with increasing As addition up to 50 mg kg(-1) but decreased with mycorrhizal colonization at As addition rates of 75 and 150 mg kg(-1). Shoot As uptake increased with mycorrhizal colonization at most As addition levels studied, but tended to decrease with addition of 150 mg As kg(-1). Total P uptake by mycorrhizal plants was elevated at As rates of 25, 50 and 75 mg kg(-1), and more P was allocated to the roots of mycorrhizal plants. Mycorrhizal plants had higher shoot and root P/As ratios at higher As application rates than did non-mycorrhizal controls. The soil of inoculated treatments had higher available As than uninoculated controls, and higher pH values at As addition levels of 25, 50 and 75 mg kg(-1). Mycorrhizal colonization may have increased plant resistance to potential As toxicity at the highest level of As contamination studied. Mycorrhizal tomato plants may have potential for phytoextraction of As from moderately contaminated soils or phytostabilization of more highly polluted sites.  相似文献   
79.
80.
In order to efficiently remove volatile organic compounds (VOCs) from indoor air, onedimensional titanate nanotubes (TiNTs) were hydrothermally treated to prepare TiO2 nanocrystals with different crystalline phases, shapes and sizes. The influences of various acids such as CH3COOH, HNO3, HCl, HF and H2SO4 used in the treatment were separately compared to optimize the performance of the TiO2 nanocrystals. Comparedwith the strong and corrosive inorganic acids, CH3COOH was not only safer andmore environmentally friendly, but also more efficient in promoting the photocatalytic activity of the obtained TiO2. Itwasobserved that the anatase TiO2 synthesized in 15 mol/L CH3COOH solution exhibited the highest photodegradation rate of gaseous toluene (94%), exceeding that of P25 (44%) by a factor ofmore than two. The improved photocatalytic activity was attributed to the small crystallite size and surface modification by CH3COOH. The influence of relative humidity (20%-80%) on the performance of TiO2 nanocrystals was also studied. The anatase TiO2 synthesized in 15 mol/L CH3COOH solution was more tolerant tomoisture than the other TiO2 nanocrystals and P25.  相似文献   
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