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391.
研究了阳离子型表面活性剂十六烷基三甲基溴化铵(CTAB)和Al3+共存,对玉米幼苗保护酶及叶绿素含量、光合速率、蒸腾速率等的影响。结果表明CTAB能加剧Al3+对玉米幼苗的毒害作用。具体表现为使幼苗超氧化物歧化酶和过氧化物酶活性升高,过氧化氢酶活性下降,超氧阴离子产生速率增大,脂质过氧化作用加剧,质膜透性上升,而叶绿素含量下降。当CTAB浓度在临界胶束浓度以上时,光合速率及蒸腾速率急剧降低。 相似文献
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A combined plasma photolysis (CPP) method for removal of CS2 from gas streams at atmospheric pressure 总被引:1,自引:0,他引:1
A combined plasma photolysis (CPP) reactor that utilizes a dielectric barrier discharge (DBD) plasma and 207 nm UV radiation from discharge-driven KrBr* excimers was designed and constructed. Gas streams containing CS2 were treated with stand-alone DBD and CPP at atmospheric pressure. In comparison to DBD, CPP greatly enhanced the removal efficiency at the same applied voltage, waste gas concentration and gas residence time. Thus the applied voltage could be reduced to a certain extent in the plasma processing of industrial wastes. Influences of the KrBr* radiation, inlet CS2 concentration and gas residence time on CS2 removal by CPP were also studied. In addition, the likely reaction mechanisms for the removal of CS2 by CPP are suggested based on the byproducts analysis. The enhanced removal efficiency and reaction mechanisms implied that the CPP process would probably be suitable for the removal of a large number of gaseous pollutants. 相似文献
395.
The role of ammonia on mercury leaching from coal fly ash 总被引:1,自引:0,他引:1
The Federal Clean Air Interstate Rule issued in March 2005 will result in many power plants employing ammonia-based technologies to control NO(x) emission. The Clean Air Mercury Rule, issued at the same time, will encourage many power plants to use various technologies to remove mercury from flue gas, generating fly ashes that contain elevated concentrations of mercury. Ammonia forms relatively strong complexes with mercury compared to most other cationic elements and, therefore, may change the leaching characteristics of mercury. Understanding the impact of ammonia on the leaching of mercury from fly ash is critical in predicting the potential environmental impact of future fly ash. Batch methods were used to investigate the ammonia impact on mercury leaching from fly ash under different pH conditions. The results indicated that mercury leaching without external ammonia addition is not significant. However, ammonia addition increased mercury leaching in the alkaline pH range, due to the formation of less adsorbable mercury-ammonia complexes. Washed ash released more mercury than the raw ash if the ammonia concentration is the same, mainly due to the dissolution of some ash components during washing which exposed more mercury on ash surface. Mercury adsorption data indicated that more than 90% of available mercury was adsorbed by fly ash even in the presence of 1000 mg l(-1) ammonia addition. 相似文献
396.
Although linear binding isotherms of hydrophobic organic chemicals (HOCs) with dissolved organic matter (DOM) are widely reported, several studies showed nonlinear HOC-DOM interactions. This study pointed out that fluorescence static quenching modeling (FSQM), which often uses a Stern-Volmer type plot to process the data from fluorescence quenching experiments, is conceptually different from the classic Stern-Volmer equation. We also emphasized that although linear Stern-Volmer plots are generally observed in literature, it does not necessarily indicate a linear HOC-DOM interaction. According to both mathematical simulation and laboratory sorption experiments in this study, nonlinear interactions could be concealed by the use of Stern-Volmer plot. Moreover, this study tested the two assumptions for applying FSQM to process binding data. Our results showed that binding coefficient (K(DOC)) for phenanthrene is neither independent of free solute concentration, nor DOM concentration, which is a critical limitation for using FSQM in a form of Stern-Volmer equation to examine HOC-DOM interactions. Therefore, the true characteristics of HOC-DOM interactions need to be examined using different ways of experimental design and data processing. 相似文献
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本文报导了“增效双效灵(HDE”的 Ames 试验结果。结果表明,HDE 有抑菌能力,其最大无抑菌浓度为1.225%(W/V)。在本试验条件下未发现其有致突变活性。 相似文献
399.
Cao Jianmin Hu Ruifa Zhu Lifen 《中国人口.资源与环境(英文版)》2007,5(1):53-57
Today, the overuse of nitrogen (N) fertilizer and high N loss result in serious nitrate pollution of water and deter the sustainable development of agriculture and social economy. A recently developed site-specific nutrient management (SSNM) can reduce fertilizer N use while preventing the yield from falling. In this paper, we raise the question of fertilizer N application in rice production through a survey of farmers' practice of fertilizer N in 18 villages of four provinces. The average rate of N application for rice production in the 18 villages was 190 kg/ha, and 76% to 100% of the total fertilizer N which was applied within l0 days after transplanting resulted in lots of nitrate leached into water. Furthermore, we tested the effect of SSNM through farmer participatory trial. The SSNM technology maintained rice yields with significantly less fertilizer N and there was no increase in labor input, as much as 31% fertilizer N were saved with the SSNM technology. Finally, the paper points that extension and further research of the SSNM technology should be an effective method to deal with the contradiction of population, food and nitrate nonpoint pollution of water resource and promote the sustainability of agriculture. 相似文献
400.
Shu Ling Zhang Zhen Xiang Xin Zhen Xiu Zhang Jin Kuk Kim 《Waste management (New York, N.Y.)》2009,29(5):1480-1485
The aim of this research was to recycle waste rubber tires by using powdering technology and treating the waste rubber tire powder with bitumen. It has been proven that the elongation at break, thermal stability and processing flowability of composites of polypropylene (PP), waste rubber tire powder (WRT) and bitumen composites are better than those of PP/WRT composite. A comparative study has been made to evaluate the influence of bitumen content and different compatibilizers on the properties of PP/WRT/bitumen composites, using a universal testing machine (UTM), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and a capillary rheometer. The results suggested that the properties of PP/WRT/bitumen composites were dependent on the bitumen content and the kind of compatibilizer used. 相似文献