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461.
Spruce (Picea abies (L.) Karst.) needles were exposed to exhaust gas containing polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) generated by combustion of polyvinyl chloride, wood, high-density polyethylene, and styrene. Photodegradation of PCDD/Fs adsorbed on spruce needles under sunlight irradiation was studied. The photodegradation of PCDD/Fs follows pseudo-first-order reaction kinetics, with photolysis half-lives ranging between 40 and 100 h. The photolysis rates of PCDF congeners are higher than PCDD congeners with the same chlorinated substitutions. Higher chlorinated PCDD/Fs tend to photolyze slowly. The wax components in spruce needles may act as proton donors and accelerate the photolysis rate. C-Cl cleavage through the addition of protons to PCDD/F molecules may be an important route for PCDD/Fs photodegradation.  相似文献   
462.
通过溶胶-凝胶法制备掺杂Ni2 的纳米TiO2,并用XRD和TEM进行了表征,发现Ni2 的掺杂减小了TiO2颗粒的粒径,Ni2 /TiO2晶型为锐钛型.通过对目标物罗丹明B的光催化降解实验,发现Ni2 的掺杂提高了TiO2的光催化活性,其降解罗丹明B的反应遵从一级反应动力学方程,Ni2 惨杂量为1.2%时的光催化活性最高.  相似文献   
463.
Photolysis of polycyclic aromatic hydrocarbons (PAHs) sorbed on surfaces of spruce [Picea abies (L.) Karst.] needles under sunlight irradiation was investigated. PAHs were produced by combustion of polyvinyl chloride (PVC), wood, high-density polyethylene (HDPE), and styrene in a stove. The factors of sunlight irradiation on the surfaces of spruce needles were taken into consideration when investigating the kinetic parameters. The photolysis of the 18 PAHs under study follows first-order kinetics. The photolysis half-lives range from 15 h for dibenzo(a,h)anthracene to 75 h for phenanthrene. Photolysis of some PAHs on surfaces of spruce needles may play an important role on the fate of PAHs in the environment.  相似文献   
464.
BOD生物传感器的研制与应用   总被引:1,自引:0,他引:1  
介绍了BOD生物传感器的原理、研制过程以及实际测定。该仪器测定BOD的周期为30min,有较高的精密度和准确度,与稀释法有良好的相关性,可以及时信息反馈,特别适用于污水处理过程中的控制分析以及BOD的快速测定。  相似文献   
465.
Phosphine (PH3) is an important factor driving the outbreak of cyanobacterial blooms that produce toxic microcystin threating human health. To clarify the physiological and biochemical responses of cyanobacteria to PH3 under elevated CO2 concentration, Microcystis aeruginosa was used in the coupling treatment of 1000 ppmv CO2 and PH3 at different concentrations respectively. The chlorophyll a (Chl-a), carotenoid, net photosynthetic rate and total protein of M. aeruginosa exhibited evidently increasing tendency under the coupling treatment of 1000 ppmv CO2 and PH3 at different concentrations (7.51 × 10?3, 2.48 × 10?2, 7.51 × 10?2 mg/L). The coupling treatments resulted in the higher concentrations of Chl-a and carotenoid of M. aeruginosa, compared to those in the control and the treatment with CO2 alone, and their enhancement increased with the increase in PH3 concentrations. The total antioxidant capacity (T-AOC) in the coupling treatment with CO2 and PH3 of 2.48 × 10?2 mg/L and 7.51 × 10?3 mg/L showed increasing tendency, compared to the treatment with PH3 alone. Additionally, the coupling treatment with 1000 ppmv CO2 and PH3 also altered the pH and DO level in the culture medium. In this regard, the coupling treatment with CO2 and PH3 at an appropriate concentration can enhance the resistance of M. aeruginosa to PH3 toxicity and is beneficial to the reproduction of M. aeruginosa, presumably resulting in potential for the outbreak of cyanobacteria bloom. Given the concern about global warming and the increase in atmospheric CO2 level, our research laid a foundation for the scientific understanding of the correlation between PH3 and cyanobacteria blooms.  相似文献   
466.
In order to study their synergistic catalytic effects in toluene degradation, CuMn_2O_4/HTS-1(HTS-1 was a titanium silicon molecular sieve), Cu_(0.7)Mn_2Y_(0.3)O_x/HTS-1 and Cu_(0.7)Mn_2Ce_(0.3)O_x/HTS-1 catalysts were prepared by the impregnation method.The textural properties, redox properties and acidity of the catalysts were characterized by X-ray diffractometer(XRD),transmission electron microscopy(TEM), scanning electron microscopy(SEM), H_2 temperature-programmed reduction(H_2-TPR), X-ray photoelectron spectroscopy(XPS),frustrated total internal reflection(FT-IR), ammonium temperature-programmed desorption(NH_3-TPD) and pyridine adsorption internal reflection(Py-IR) measurements.The potential roles of Lewis acid sites(activating dioxygen) were discussed, and the experimental results indicated that the most efficient route for toluene degradation over Cu_(0.7)Mn_2Ce_(0.3)O_x/HTS-1(toluene conversion rate of 90%(T99) = 295℃) was ascribed to regulation of the synergistic effects of redox properties(activating molecular toluene) and Lewis acid sites(activating dioxygen).The Mars–Van–Krevelen(MVK) model was adopted to describe the reaction process of toluene oxidation, which gave an in-depth view into the toluene degradation over CuMn_2O_4/HTS-1, Cu_(0.7)Mn_2Y_(0.3)O_x/HTS-1 and Cu_(0.7)Mn_2Ce_(0.3)O_x/HTS-1.In addition, the synergistic effects between redox properties and Lewis acid sites were studied in detail.  相似文献   
467.
468.
生活垃圾填埋场矿化垃圾分选研究   总被引:10,自引:0,他引:10  
对上海市老港生活垃圾填埋场填埋龄为1~14年的矿化垃圾进行了分选研究.结果表明,填埋龄在8年以上矿化垃圾细料(粒径<50 mm)的百分比约占60%,而填埋龄低于5年的矿化垃圾细料比例低于40%.开采出来的垃圾经分选后的产品可得到有效的资源化利用.  相似文献   
469.
通过对超化煤矿13011和21051两个了开采条件相似的综放丽瓦斯治理情况比较分析,得出瓦斯抽放是“三软”特厚煤层高沼综放工作而瓦斯综合治理的有效途径。  相似文献   
470.
土地利用规划与旅游规划协调研究   总被引:8,自引:0,他引:8  
就土地利用规划和旅游规划之间难以衔接与协调的问题,依据规划及社会经济发展的基本原则,从"两规"的差异性、"两规"协调的理论和法律依据、"两规"协调的途径三个方面,试图分析和解决这一长期困扰土地利用规划界与旅游规划界的难题.  相似文献   
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