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141.
James V. Bonta 《Journal of the American Water Resources Association》2000,36(4):869-887
ABSTRACT: Prior to PL95–87 little research had been conducted to determine the impacts of mining and reclamation practices on sediment concentrations and yields on a watershed scale. Furthermore, it was unknown whether sediment yield and other variables would return to undisturbed levels after reclamation. Therefore, three small watersheds, with differing lithologies and soils, were monitored for runoff and suspended sediment concentrations during three phases of watershed disturbances: undisturbed watershed condition, mining and reclamation disturbances, and post‐reclaimed condition. Profound increases in suspended‐sediment concentrations, load rates, and yields due to mining and reclamation activities, and subsequent drastic decreases after reclamation were documented. Even with increases in runoff potential, reductions in suspended‐sediment concentrations and load rates to below or near undisturbed‐watershed levels is possible by using the mulch‐crimping technique and by removing diversions. Maximum concentrations and load rates occurred during times of active disturbances that exposed loose soil and spoil to high‐intensity rains. Sediment concentrations remained elevated compared with the undisturbed watershed when diversions were not well maintained and overtopped, and when they were not removed for final reclamation. Diversions are useful for vegetation establishment, but should be maintained until they are removed for final reclamation after good vegetative cover is established. 相似文献
142.
针对工业循环水处理系统中使用磷系缓蚀阻垢剂带来的磷排放问题,以马来酸酐和3-巯基丙酸为主要原料,在催化剂作用下应用“一步法”合成S-羧乙基硫代琥珀酸(CETSA)无磷缓蚀阻垢剂,通过红外(IR)、核磁共振(13CNMR)等方法对其结构进行了表征.采用碳酸钙沉积法、旋转挂片法对CETSA的阻垢缓蚀性能进行评价,考察了加药量、水温、pH值、水流转速等对CETSA阻垢缓蚀性能的影响.结果表明,当加药量为110mg/L、循环水温度低于50℃、pH值为6~8、水流转速低于100 r/min时,CETSA对A3碳钢的腐蚀率小于0.25mm/a,最大缓蚀率可达61.3%,最大阻垢率达88.4%.CETSA是一种小分子多羧酸结构,其具有较高的缓蚀阻垢性能可能是因为与水中的钙镁离子发生了螯合,生成了稳定的络合物抑制结垢,同时非极性键、烷基等亲水基吸附于金属表面,电负性较高的O、S元素与Fe产生强吸附,形成的致密保护膜有效抑制了金属腐蚀.经测算,10%水剂的CETSA生产成本约为3 047元/t,总磷减排量可达3~5g/m3循环水排水.研究表明,CETSA可替代传统磷系缓蚀阻垢剂,适于电力、钢铁、化工、油田等行业的循环冷却水系统. 相似文献
143.
城市的发展与扩张导致生物栖息地与农林用地的减少,同时大量不透水材料的应用,打破了雨水的良性循环,导致城市洪涝干旱年年发生.于是,雨水花园更为广泛的应用模式成为了城市建设者们探索的焦点.以武汉市百步亭景兰苑小区为例,该设计尝试将雨水花园与住区景观设计相结合,营造一个安全、生态、经济、美观的城市绿色住区环境.图1,参5. 相似文献
144.
研究温压炸药爆炸初期弹内爆炸波作用过程,可以进一步分析温压炸药分散爆轰的作用机理,为温压炸药武器设计和系统优化提供可靠依据.设计了用测时法研究温压炸药爆轰波传播速度的试验装置,并用探针对相同组分和密度条件下、温压战斗部弹内爆炸初期的爆炸作用过程进行了对比试验,记录了触发时间信号,计算并分析了温压炸药弹内爆炸波的传播特性,得到了波阵面与弹径方向夹角α的变化规律.试验结果表明,温压炸药的爆轰波传播速度为4.632km/s,其弹内爆轰波的传播特性与中心高能分散药的爆轰波有密切联系,通过合理设计弹体结构和比药量,可以实现温压炸药的分散爆轰,提高温压炸药的爆炸威力. 相似文献
145.
146.
- DOI: http://dx.doi.org/10.1065/espr2006.02.294
Background, Aim and Scope. To better address the requirements of the changing multilateral order, the United Nations Industrial
Development Organization (UNIDO) Cleaner Production Programme, in 2004, developed the new Sustainable Industrial Resource
Management (SIRM) approach. This approach is in accordance with the principles decided at the United Nations Conference on
Environment and Development (UNCED) in Rio de Janeiro, Brazil in 1992. Unlike the traditional approaches to environmental
management, the SIRM concept captures the idea of achieving sustainable industrial development through the implementation
of circular material and energy flows in the entire production chain and reduction of the amount of material and energy used
with greater efficiency solutions. The SIRM approach seeks to develop new models to encourage a shift from selling products
to supplying services, modifying, in this manner, the supplier/user relationship and resulting in a win-win situation for
the economy and the environment. Chemical Leasing represents such a new service-oriented business model and is currently being
promoted by UNIDO′s Cleaner Production Programme.
Main Features. One of the potential approaches to address the problems related to ineffective use and over-consumption of
chemicals is the development and implementation of Chemical Leasing business models. These provide concrete solutions to the
effective management of chemicals and on the ways negative releases to the environment can be reduced. The Chemical Leasing
approach is a strategy that addresses the obligations of the changing international chemicals policy by focusing on a more
service-oriented strategy. Mexico is one of the countries that were selected for the implementation of UNIDO's demonstration
project to promote Chemical Leasing models in the country. The target sector of this project is the chemical industry, which
is expected to shift their traditional business concept towards a more service and value-added approach. This is being achieved
through the development of company specific business models that implement the above-indicated Chemical Leasing concept with
the support from the Mexican National Cleaner Production Centre (NCPC).
Results and Conclusions. The implementation of Chemical Leasing in Mexico has proven to be an efficient instrument in enhancing
sustainable chemical management and significantly reducing emissions in Mexico. Several companies from the chemical industrial
sector implement or agreed to implement chemical leasing business models. Based on the positive findings of the project,
several Mexican companies started to negotiate contents of possible Chemical Leasing contracts with suitable business partners.
The project further aimed at disseminating information on Chemical Leasing. It successfully attracted globally operating companies
in the chemicals sector to explore possibilities to implement Chemical Leasing business models in Mexico. At the international
level, the results of the UNIDO project were presented on 20TH September 2005 during a side event of the Strategic Approach
to International Chemicals Management (SAICM) Preparation Conference in Vienna.
Recommendations and Outlook. To facilitate the promotion and application of Chemical Leasing project at international level,
UNIDO is currently developing a number of tools to standardize Chemical Leasing projects. These include, among others, Chemical
leasing contract models; Chemical Leasing data base to find partners for chemical leasing; and guidelines to implement Chemical
Leasing projects and work programmes. 相似文献
147.
Underground coal mine explosions is perhaps the most hazardous danger in the coal mining industries. Efforts have been made to abate the coal dust explosion by applying rock dust either dry or wet. Dry dust has the best lift characteristic which efficiently quenches the flame propagation of a potential explosion. As a trade-off, undesired respirable dust particles are thereby generated imposing a severe health hazard on coal miners. Wet dusting is an alternative to dry dusting which significantly reduces the exposure to respirable dust particles. However, wet dust is subject to adverse caking issues which lead to a drastic reduction in the dispersibility of the particles. The present work summarizes the studies conducted to date regarding the surface modification of rock dust particles for the purpose of eliminating or alleviating the problems accompanying coal mine dusting applications, meanwhile improving the dispersive properties of dust particles and the ability to suppress the coal dust explosion. 相似文献
148.
Veerasamy Kothandaraman Ralph L. Evans 《Journal of the American Water Resources Association》1981,17(4):607-613
: Chemical quality characteristics of the Illinois waterway covering a stretch of 270 river miles were monitored at approximately 10 mile intervals, during the period June to September of 1978 and 1979. A statistical method was used to define the interstation relationships for the chemical parameters. These mathematical models were used to predict the effects of Lake Michigan diversion. The mineral content of the mixed flow resulting from increased diversions are not likely to be altered drastically. 相似文献
149.
Carl D. Settergren Larry C. Tennyson 《Journal of the American Water Resources Association》1979,15(5):1353-1364
ABSTRACT: A number of criteria can be used in the selection of an area for the irrigation disposal of secondary treated waste water. The inherent capacity of the surface soil to retain, or at least detain, the various nutrient ions passing through the profile in the percolating waters becomes the prime consideration in regions with shallow water tables or in Karst areas such as the Missouri Ozarks where the risk of ground water supply contamination is high. A comprehensive study of the nutrient renovation potential of several soils was undertaken at a proposed effluent irrigation site along the Ozark National Scenic Riverways in south central Missouri. The surface soil hydrology was evaluated employing selected soil water parameters. Exchange equilibria studies determined the retention capacity for Ca and Mg while the concentrations of other selected ions were analyzed in the soil water to measure their retention time and net removal. The movement of a bromine tracer was monitored as an index of the renovation capacity of these soils for the more mobile anions such as nitrate. Neutron activation analysis proved to be a useful tool in the water quality analyses. All surface soil profiles demonstrated some degree of nutrient renovation for the various nutrients studied. 相似文献
150.