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81.
总量控制费用分摊的多目标规划模型及解法 总被引:1,自引:0,他引:1
文章指出了污染物总量控制规划中公平合理分摊优化治理投资费用的重要性,分析了现有的优化治理投资费用分摊方法存在的问题,建立了公平合理分摊优化治理投资费用的多目标规划模型,提出用最短距离理想点法加以求解,并通过实例验证了该方法的合理性。结果表明该模型及解法既可以保证总量控制规划方案的社会整体效益最大,又不失公平,从而确保总量控制规划方案的顺利实施。 相似文献
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Yu X Zhou P Zhou X Liu Y 《Environmental science and pollution research international》2005,12(4):221-226
Background Little is known about metabolism rates of environmental chemicals by vegetation. A good model compound to study the variation
of rates among plant species is cyanide. Vascular plants possess an enzyme system that detoxifies cyanide by converting it
to the amino acid asparagine. Knowledge of the kinetic parameters, the half-saturation constant (Km) and the maximum metabolic
capacity (vmax), is very useful for enzyme characterization and biochemical purposes. The goal of this study is to find the
enzyme kinetics (KM and vmax) during cyanide metabolism in the presence of Chinese vegetation, to provide quantitative data
for engineered phytoremediation, and to investigate the variation of metabolic rates of plants.
Methods Detached leaves (1.0 g fresh weight) from 12 species out of 9 families were kept in glass vessels with 100 mL of aqueous
solution spiked with potassium cyanide at 23°C for 28 h. Four different treatment concentrations of cyanide were used, ranging
from 0.44 to 7.69 mg CN/L. The disappearance of cyanide from the aqueous solution was analyzed spectrophotometrically. Realistic
values of the half-saturation constant (KM) and the maximum metabolic capacity (vmax) were estimated by a computer program
using non-linear regression treatments. As a comparison, Lineweaver-Burk plots were also used to estimate the kinetic parameters.
Results and Discussion The values obtained for KM and vmax varied with plant species. Using non-linear regression treatments, values of vmax and
KM were found in a range between 6.68 and 21.91 mg CN/kg/h and 0.90 to 3.15 mg CN/L, respectively. The highest vmax was by
Chinese elder (Sambucus chinensis), followed by upright hedge-parsley (Torilis japonica). The lowest vmax was demonstrated
by the hybrid willow (Salix matssudana x alba). However, the highest KM was found in the water lily (Nymphea teragona), followed
by the poplar (Populus deltoides Marsh). The lowest KM was demonstrated by corn (Zea mays L.). The values of vmax were normally
distributed with a mean of 13 mg CN/kg/h.
Conclusions Significant removal of cyanide from aqueous solution was observed in the presence of plant materials without phytotoxicity,
even at high doses of cyanide. This gives rise to the conclusion that the Chinese plant species used in this study are all
able to efficiently metabolize cyanide, although with different maximum metabolic capacities. A second conclusion is that
the variation of metabolism rates between species is small. All these plants had a similar KM, indicating the same enzyme
is active in all plants.
Recommendations and Outlook Detoxification of cyanide with trees seems to be a feasible option for cleaning soils and water contaminated with cyanide.
For phytoremediation projects, screening appropriate plant species adapted to local conditions should be seriously considered.
More chemicals should be investigated to find common principles of the metabolism of environmental chemicals by plants. 相似文献
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Lucy T. González Francisco E. Longoria-Rodríguez Margarita Sánchez-Domínguez Cesar Leyva-Porras Karim Acuña-Askar Boris I. Kharissov Alejandro Arizpe-Zapat Juan M. Alfaro-Barbosa 《环境科学学报(英文版)》2018,30(12):32-49
During the winter period (January–March 2016), the total suspended particles (TSP) and particulate matter smaller than 2.5 μm (PM2.5) were characterized by the application of various analytical techniques in four zones of the Metropolitan Area of Monterrey in Mexico. To evaluate the seasonal variation of some elements in the particulate matter, the results of this study were compared with those obtained during the summer season (July–September 2015). The speciation of the C1s signal by X-ray photoelectron spectroscopy revealed the contribution of aromatic and aliphatic hydrocarbons as the main components in both seasons. Conversely, carboxylic groups associated with biogenic emissions were detected only in winter. The percentages of SO42 ? ions were lower in winter, possibly caused by the decrease in the solar radiation, and relative humidity recorded. The results of the ICP analysis revealed that Fe, Zn and Cu were the most abundant metals in both TSP and PM2.5 in the two seasons. There were significant seasonal variations for concentrations of As, Ni and Zn in the urban area and for Fe, As, Cd, Ni and Zn in the industrial zone. This was attributed to the greater burning of fuels as well as to an increase in vehicular traffic, the effect of thermal inversion and changes in some meteorological parameters. The results of the sequential microanalysis by Raman spectroscopy and SEM/EDS allowed observation of deposits of carbonaceous material on the particles and to perform the speciation of particles rich in Fe and Pb, which helped infer their possible emission sources. 相似文献
86.
利用AA3流动注射分析仪,同时对地表水中的挥发酚和氰化物进行测定,分析流程中使用了在线恒温蒸馏器。同传统的分析方法相比,本法分析测定数据准确、可靠、高效,大大缩短了测定时间,只需将两种标准配制成混合标样,一次取样完成两个项目的测定。回收率为90%~110%,相关系数达到0.9992以上。 相似文献
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