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111.
从废催化剂中回收钼的新工艺 总被引:4,自引:2,他引:2
确定了用新型复合浸取剂从废催化剂中回收钼的最佳工艺条件废催化剂颗粒度100目焙烧温度750℃,焙烧时间1h复合浸取剂中助浸剂质量为5%,浸取固液质量比1:3,浸取温度60℃,浸取时间6h,在该条件下,钼的浸取率达到92.7%~95.5%。 相似文献
112.
Ted V. Hromadka Timothy J. Durbin 《Journal of the American Water Resources Association》1986,22(2):249-255
ABSTRACT: A two-dimensional dam-break model was used to predict the inundated area on an alluvial fan downslope from the Orange County Reservoir. The model is based upon a diffusion form of the continuity and momentum equations for long waves in shallow water, and the governing equation is solved by an explicit numerical scheme. In a comparison with a one-dimensional model, the two-dimensional model predicts a wider inundated area. 相似文献
113.
Whitelaw G Vaughan H Craig B Atkinson D 《Environmental monitoring and assessment》2003,88(1-3):409-418
Community-based ecosystem monitoring activities in Canada are increasing in response to a number of factors including: (i) the needs of decision-makers for timely information on local environmental changes; (ii) limited use of government monitoring data and information by decision makers; (iii) government cuts to monitoring programs; (iv) the increasingly recognized need to include stakeholders in planning and management processes; and (v) the desire of citizens to contribute to environmental protection. To date there has been no network coordination of community based monitoring in Canada. This paper reports on the establishment of the Canadian Community Monitoring Network by Environment Canada's Ecological Monitoring and Assessment Network Coordinating Office and the Canadian Nature Federation. Information on research prepared in support of network establishment is presented along with a discussion of the potential of the network. 相似文献
114.
Jennifer K. Holman‐Dodds A. Allen Bradley Kenneth W. Potter 《Journal of the American Water Resources Association》2003,39(1):205-215
ABSTRACT: As watersheds are urbanized, their surfaces are made less pervious and more channelized, which reduces infiltration and speeds up the removal of excess runoff. Traditional storm water management seeks to remove runoff as quickly as possible, gathering excess runoff in detention basins for peak reduction where necessary. In contrast, more recently developed “low impact” alternatives manage rainfall where it falls, through a combination of enhancing infiltration properties of pervious areas and rerouting impervious runoff across pervious areas to allow an opportunity for infiltration. In this paper, we investigate the potential for reducing the hydrologic impacts of urbanization by using infiltration based, low impact storm water management. We describe a group of preliminary experiments using relatively simple engineering tools to compare three basic scenarios of development: an undeveloped landscape; a fully developed landscape using traditional, high impact storm water management; and a fully developed landscape using infiltration based, low impact design. Based on these experiments, it appears that by manipulating the layout of urbanized landscapes, it is possible to reduce impacts on hydrology relative to traditional, fully connected storm water systems. However, the amount of reduction in impact is sensitive to both rainfall event size and soil texture, with greatest reductions being possible for small, relatively frequent rainfall events and more pervious soil textures. Thus, low impact techniques appear to provide a valuable tool for reducing runoff for the events that see the greatest relative increases from urbanization: those generated by the small, relatively frequent rainfall events that are small enough to produce little or no runoff from pervious surfaces, but produce runoff from impervious areas. However, it is clear that there still needs to be measures in place for flood management for larger, more intense, and relatively rarer storm events, which are capable of producing significant runoff even for undeveloped basins. 相似文献
115.
论"性能化"防火设计中的"设计火灾场景 总被引:28,自引:3,他引:28
通过一个日本的案例简要讨论了“性能化”防火设计中“设计火灾场景”的方法与步骤,其中主要包括火灾模拟试验的数学模型,目的在于为我国的“性能化”设计提供指导。该案例取自2002年3月在澳大利亚。墨尔本召开的第四次“性能化”规范和消防安全设计方法的国际会议论文集(英文版)。 相似文献
116.
通过溶液培养试验,研究外源添加Mo对2种价态砷(As(III)和As(V))胁迫下水稻吸收积累Mo和As的影响。结果表明,这2种价态的As对水稻生长均有抑制作用,As(III)比As(V)对水稻毒害更明显,添加Mo可缓解As对水稻的毒害。As添加可影响水稻根系和茎叶对Mo的吸收积累,但是不同价态As对Mo积累量的影响不一致。同时,Mo的添加也可以显著地降低水稻根系和茎叶对2个价态As的吸收积累。在100 μmol?L-1 As(III)处理下,添加0.1和0.5 mg?L-1的Mo可导致水稻根系As积累量分别比对照处理降低38.8%和52.8%,茎叶As积累量分别降低5.1%和10.6%;当As(V)浓度为100 μmol?L-1时,添加0.1和0.5 mg?L-1的Mo可导致水稻根系As积累量分别比对照处理降低15.4%和62.4%,茎叶As积累量分别降低11.9%和23.7%。Mo的添加还能显著地降低2种价态As在水稻根系和茎叶中的富集系数。因此,通过施用适量的Mo肥可以用来防治农田As污染,降低As对人体健康的危害。 相似文献
117.
外源Mo降低As(Ⅲ)和As(Ⅴ)对水稻的毒性及As的积累 总被引:3,自引:0,他引:3
通过溶液培养试验,研究外源添加Mo对2种价态砷(As(Ⅲ)和As(Ⅴ))胁迫下水稻吸收积累Mo和As的影响。结果表明,这2种价态的As对水稻生长均有抑制作用,As(Ⅲ)比As(Ⅴ)对水稻毒害更明显,添加Mo可缓解As对水稻的毒害。As添加可影响水稻根系和茎叶对Mo的吸收积累,但是不同价态As对Mo积累量的影响不一致。同时,Mo的添加也可以显著地降低水稻根系和茎叶对2个价态As的吸收积累。在100μmol·L~(-1)As(Ⅲ)处理下,添加0.1和0.5 mg·L~(-1)的Mo可导致水稻根系As积累量分别比对照处理降低38.8%和52.8%,茎叶As积累量分别降低5.1%和10.6%;当As(V)浓度为100μmol·L~(-1)时,添加0.1和0.5 mg·L~(-1)的Mo可导致水稻根系As积累量分别比对照处理降低15.4%和62.4%,茎叶As积累量分别降低11.9%和23.7%。Mo的添加还能显著地降低2种价态As在水稻根系和茎叶中的富集系数。因此,通过施用适量的Mo肥可以用来防治农田As污染,降低As对人体健康的危害。 相似文献
118.
119.
Manuela Baumgarten Christian Huber Patrick Büker Hans-Peter Dietrich Christian Heerdt Rainer Matyssek 《Environmental pollution (Barking, Essex : 1987)》2009,157(7):2091-2107
Exposure and flux-based indices of O3 risk were compared, at 19 forest locations across Bavaria in southern Germany from 2002 to 2005; leaf symptoms on mature beech trees found at these locations were also examined for O3 injury. O3 flux modelling was performed using continuously recorded O3 concentrations in combination with meteorological and soil moisture data collected from Level II forest sites. O3 measurements at nearby rural open-field sites proved appropriate as surrogates in cases where O3 data were lacking at forest sites (with altitude-dependent average differences of about 10% between O3 concentrations). Operational thresholds of biomass loss for both O3 indices were exceeded at the majority of the forest locations, suggesting similar risk under long-term average climate conditions. However, exposure-based indices estimated higher O3 risk during dry years as compared to the flux-based approach. In comparison, minor O3-like leaf injury symptoms were detected only at a few of the forest sites investigated. Relationships between flux-based risk thresholds and tree response need to be established for mature forest stands for validation of predicted growth reductions under the prevailing O3 regimes. 相似文献
120.
In this study, the surface chemical functional groups of Bacillus cereus biomass were identified by Fourier transform infrared (FTIR) analytical technique. It had been shown that the B. cereus cells mainly contained carboxyl, hydroxyl, phosphate, amino and amide functional groups. The potentiometric titration was conducted to explain the surface acid-base properties of aqueous B. cereus biomass. The computer program FITEQL 4.0 was used to perform the model calculations. The optimization results indicated that three sitesthree pKas model, which assumed the cell surface to have three distinct types of surface organic functional groups based on the IR analysis results, simulated the experimental results very well. Moreover, batch adsorption experiments were performed to investigate biosorption behavior of Cu(Ⅱ) and Pb(Ⅱ) ions onto the biomass. Obviously, the adsorption equilibrium data for the two ions were reasonably described by typical Langmuir isotherm. 相似文献