Co/AC催化剂的制备及CWPO处理腈纶废水研究

以活性炭为载体,负载活性组分金属Co,制备了Co／AC催化剂,采用催化过氧化氢氧化技术（CWPO）处理腈纶废水,考察其催化氧化性能。实验结果表明：将预处理后的20-40目粒状活性炭浸渍于质量浓度为7％Co（NO3）2溶液中,浸渍9h后,经自然晾干,在500℃的条件下焙烧4h得到的Co／AC催化剂催化效果最好。     

活性炭纤维基催化剂在烟气脱硝中的应用

以活性炭纤维（ACF）为载体的催化剂具有良好的脱硝性能，材料、负载方式、负载量、活性组分等的不同都会对NOx的脱除率有很大的影响。在目前研究中，活性炭纤维基催化剂主要应用于催化分解法和选择性催化还原法（SCR）。本文介绍了活性炭纤维的基本特性，比较了不同催化剂的脱硝性能，并在此基础上提出了今后的研究方向。     

催化燃烧工艺处理有机废气污染物分析

以催化燃烧法处理有机废气能耗低、无二次污染,文章叙述了催化剂载体选型、催化剂选型、活性组分的负载方法、催化性能影响因素、热平衡分析,并结合案例为催化燃烧在工程上的应用提供了参考。     

反应条件对活性炭负载铈催化剂NH3选择性催化还原NO影响的研究

通过程序升温反应考察活性炭负载铈(Ce/AC)催化剂选择性催化还原NO的性能。探讨反应温度、空速、NO初始浓度、O2浓度、NH3浓度以及SO2的存在对其催化性能的影响。实验结果表明,催化剂的催化活性随温度的上升而逐渐增加,在150℃后趋于平稳,NO转化率接近100%;NO进口浓度的增加,催化剂对NO的脱除效率有较小幅度下降;在没有氧气的存在时,NO的转化率只有20%左右,随着氧气的加入,转化率明显增加,当氧含量到1%以后,NO的转化率趋于平缓,稳定在90%以上;SO2对催化剂有很强的毒性,烟气中加入SO2后,催化剂对NO的去除率明显的下降。     

载铜活性炭催化氧化干法腈纶废水的研究

通过浸渍法制备了载铜活性炭(Cu/AC)催化剂,用于催化过氧化物氧化干法腈纶废水,结果表明:Cu/AC催化活性高于均相催化剂Cu(NO3)2,Cu溶出量则小于均相催化剂.非均相催化氧化对干法腈纶废水有很好的处理效果.催化剂的活性和稳定性与制备条件关系很大,通过单因子影响实验,确定催化剂的最佳制备条件为焙烧温度700℃,焙烧时间4小时,浸渍溶液初始浓度10.6gCu/L,浸渍时间20小时.     

非均相催化臭氧化处理钻井废水的研究

以油田钻井废水为处理对象,采用基于臭氧的非均相催化氧化处理工艺,负载了MnO_2催化剂强化臭氧处理效果,实验对比分析单独臭氧化和非均相催化臭氧化的处理效果差异,确定最佳工艺参数条件。X射线衍射分析表明,过量浸渍法制备的催化剂中含有大量活性组分MnO_2,使非均相催化臭氧化去除钻井废水COD的效率提高了45.8%。经工艺优化后,确定非均相催化臭氧化处理钻井废水最佳条件为:催化剂加量50mg/L、反应pH值为11、反应温度20℃、臭氧浓度85mg/L、处理时间50min,此时废水COD最大去除率为83.1%。通过5次重复实验验证,催化剂和系统稳定性几乎不受影响,出水均达到GB 8978—1996《污水综合排放标准》一级标准。     

一体化碳纤维+催化再生设备处理VOCs

连续沉浸机在生产过程中产生的废气中主要含有苯乙烯、VOCs污染因子,宜采用活性碳纤维吸附+催化燃烧工艺进行净化。通过工程实例介绍了活性碳纤维吸附+催化燃烧一体化设备的构造、工作原理、设备参数、注意事项以及运行效果。     

SCR催化剂失活机理分析及防治措施

选择性催化还原法(SCR)是火电厂常用的外加还原剂还原NOx将其转变为N2和O2的烟气治理方法。还原过程中,催化剂是反应核心部分,但烟气及其携带灰分的性质会致使金属氧化物催化剂失活(中毒),直接影响到火电厂运行的脱硝效率。通过对金属氧化物催化剂中毒机理的分析,提出在采用负载型复合催化剂,根据灰分选择合适催化剂载体结构的同时,适时采用后置式公用SCR布置形式等措施,可达到延长催化剂使用寿命、提高脱硝效率、减少运营成本的目的。     

凹凸棒石黏土在烟气脱硝中的研究进展

当前我国脱硝行业控制氮氧化物排放很大程度上决定于催化剂的性能、成本等。广泛使用的二氧化钛基脱硝催化剂尽管性能好,但成本较高。相反,具有"千种用土"、"万土之王"的凹凸棒石黏土兼具性能良好和成本低廉的特点,因此可考虑用于脱硝。简述了凹凸棒石黏土的组成、资源分布、开发现状及其主要性能(吸附性和催化性),分析总结了凹凸棒石黏土基脱硝用催化剂的研究进展。研究将凹凸棒石黏土用作催化剂载体或者催化载体粘结剂制备出的催化剂,多以负载金属或者过渡金属作为催化活性组分,脱硝率一般都能达80%以上,部分催化剂在一定SO2浓度下依然有较好的催化转化效率。研究发现,凹凸棒石黏土基脱硝催化剂具有较好的催化反应性能,不仅有望一体式解决脱硝、脱汞、抗硫等问题,而且还将大大降低脱硝成本。     

臭氧分解的动力学和机理概述

本文介绍了催化分解臭氧过程中,臭氧在催化剂表面的吸附形态,及各种条件下的反应下氧催化分解的动力学和机理。     

RECENT RESEARCH ON EFFECTS OF CLIMATE CHANGE ON WATER RESOURCES1

ABSTRACT: Concentrations of atmospheric CO2 and other radiatively active trace gases have risen since the Industrial Revolution. Such atmospheric modifications can alter the global climate and hydrologic cycle, in turn affecting water resources. The clear physical and biological sensitivities of water resources to climate, the indication that climate change may be occurring, and the substantial social and economic dependencies on water resources have instigated considerable research activity in the area of potential water resource impacts. We discuss how the literature on climate change and water resources responds to three basic research needs: (1) a need for water managers to clearly describe the climatic and hydrologic statistics and characteristics needed to estimate climatic impacts on water resources, (2) a need to estimate the impacts of climate change on water resources, and (3) a need to evaluate standard water management and planning methods to determine if uncertainty regarding fundamental assumptions (e.g., hydrologic stationarity) implies that these methods should be revised. The climatic and hydrologic information needs for water resource managers can be found in a number of sources. A proliferation of impact assessments use a variety of methods for generating climate scenarios, and apply both modeling approaches and historical analyses of past responses to climate fluctuations for revealing resource or system sensitivities to climate changes. Traditional techniques of water resources planning and management have been examined, yielding, for example, suggestions for new methods for incorporating climate information in real-time water management.     

THE INFLUENCE OF DRAW-DOWN ON RECREATION ON THE TRENT CANAL RESERVOIR-LAKES1

ABSTRACT: Water-based outdoor recreation constitutes an important benefit in many multiple-use projects. One problem frequently encountered, however, is the fluctuation of the water-level in a reservoir, especially if draw-downs occur during the summer recreation season. The Trent Canal in Ontario, Canada, forms a unique recreation waterway of some 240 miles of canal and navigable lakes and rivers. For the control of the water in the canal, the Canadian Federal government manages 44 reservoir-lakes as water-storage sites to augment the flows in the canal. While most disputes in water allocation for recreation generally involve recreation uses versus other, non-recreation uses, in the case of the Trent Canal and its reservoir-lakes the dispute in water allocation exists between two competing recreation-uses: for recreation boating on the Canal and its waterway, and for recreation use of the reservoir-lakes. Each use has its own duty-of-water in terms of requirements, or water conditions, for its optimum use. On the reservoir-lakes, by far the largest recreation user-group, is made up of the owners of private shoreline summer cottages (cabins). Draw-downs on the reservoir-lakes, in some cases as much as 13 feet, hence constitute a negative externality imposed by the canal, especially since water-level lowering takes place continuously throughout the summer. In-depth interviews conducted with over 100 cottage-owners indicate four main conclusions. First, the previous user assumptions of the extent of the negative effect of water-level fluctuation on recreation had been exaggerated. Only in extreme draw-downs during infrequent dry years would draw-down constitute a serious imposition. Second, water-level fluctuation does constitute a form of inconvenience to the private riparian recreation property owners, but it does not generally reduce the quantity of recreation use of the reservoir-lakes. Third, there is evidence that reservoir-lake users have learned to adapt successfully to water-level draw-downs. Fourth, the shoreline physiography of the location of a riparian owner strongly influences the way in which draw-down affects attitudes and opinions. The complex jurisdictional split of the land and water resources of the region points to the need to establish a Trent Canal Authority, to oversee the proper use and development of the canal, its waterway, and the reservoir-lakes.     

THE COMMITTEE ON NATURAL RESOURCES AND SOME ISSUES ON THE INTERNATIONAL AGENDA

The Committee on Natural Resources, which meets every two years, is the primary intergovernmental body of the United Nations dealing with natural resources matters. In the following article, the author summarizes briefly some of the issues before the Committee at its most recent session, which convened in Geneva in May 1977, and the recommendations adopted by participating governments.     

THE IMPACTS OF WATERWAY USER FEES ON GRAIN TRANSPORTATION ON THE SNAKE-COLUMBIA RIVER1

ABSTRACT: Grain transportation is a major economic activity on the multiple use Snake-Columbia River System. Congress is currently considering increased transportation user fees aimed at recapturing federal expenditures for waterway operations and maintenance. Three types of fee structure and four levels of cost recovery are evaluated using a network program model. In each case traffic is diverted away from the river to other Puget Sound ports via truck and rail transport modes. Grain shippers in the region will be adversely affected by a higher transport bill. The Lower Columbia River port economic activities will be negatively affected; however, competitive uses of the river, recreation, and hydroelectric generation will likely benefit modestly.