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341.
342.
生态产业园区是循环经济在区域层面的实践模式,是园区可持续发展的方向和趋势.基于自然生态系统食物链类型,分析了产业生态系统的资源利用方式以及成员间的相互关系,尝试性地提出适合我国生态产业园区发展的3种典型模式:牧食型生态产业园区、寄生型生态产业园区和腐生型生态产业园区.以合肥市为例,对生态产业园区发展模式选择和产业生态链构建进行了具体分析.  相似文献   
343.
Continuous on-site measurements of 50 speciated volatile organic compounds (VOCs) were conducted in downtown Guangzhou to characterize the sources and concentration profiles of ambient VOCs. The synchronicity in diurnal variation between the VOCs and NO suggests that traffic emissions were responsible for the observed VOCs in downtown Guangzhou.It was found that the three major constituent species of liquefied petroleum gas (LPG), i.e., propane, iso-butane, and n-butane, together termed LPG alkanes, contributed, on average, 24% of the total VOCs (TVOCs). Their high correlation and synchronized diurnal variations between NO and the LPG alkanes suggest that their origin lies in LPG fueled car exhaust in Guangzhou. LPG buses and taxis were likely to be responsible for the bulk of ambient LPG species. Using propane and 3-methyl pentane (3MC5A) as the indicators for the LPG and gasoline emissions, respectively, the emissions of the LPG fleet were found to increase more than those of the gasoline fleet during the morning and evening rush hours, as well the noontime break in downtown Guangzhou.Although LPG alkanes account for 24% of the TVOC, their contribution to the total ozone forming potential (OFP) is only about 7%. Ethylene and propylene contribute about 26% to the total OFP despite their lower contribution of 16% to the TVOC.  相似文献   
344.
多氯联苯降解菌Pcb6所含质粒的某些特性的研究   总被引:1,自引:0,他引:1  
研究证明,某些土壤微生物可以分解多氯联苯(PCBs)。笔者也曾报道过几株能够降解PCBs的细菌。细菌降解质粒可赋予细菌分解代谢各种复杂有机化合物的能力。Kamp和Furukawa等曾分别发现了能够将4-氯联苯和3,5-二氯联苯转化成对应的氯苯甲酸的质粒。 Pseudo monas.sp.Pcb6是一株含有质粒的PCBs降解菌,它对4-PCB、PCB-42、PCB-48和Aroclor1254降解效果显著,并具有明显的脱氯作用。本实验对该质粒的某些生物学特性进行了研究。  相似文献   
345.
The remediation of wastewater requires treatment technologies which are robust, efficient, simple to operate and affordable such as adsorption. Lately, three-dimensional (3D) graphene based materials have attracted significant attention as effective adsorbents for wastewater treatment. The intrinsic properties of 3D graphene structure such as large surface area and interconnected porous structure can facilitate the transport of pollutants into the 3D network and provide abundant active sites for trapping the pollutants. For the synthesis of 3D graphene structure, ice-templating is commonly practiced due to its facile steps, cost effectiveness and high scalability potential. This review covers the ice-templating fabrication technique for 3D graphene based materials and their application as adsorbents in eliminating dyes and heavy metals from aqueous media. The assembly mechanisms of the ice-templating fsynthesis are comprehensively discussed. Further discussion on the fundamental principles, critical process parameters and characteristics of ice-templated 3D graphene structures is also included. A thorough review on the mechanisms for batch adsorption of dyes and heavy metals is presented based on the structures and properties of the 3D graphene materials. The review further evaluates the dynamic adsorption in packed columns and the regeneration of 3D graphene based materials.  相似文献   
346.
环境—经济系统能值(Emergy)评价:介绍Odum的能值理论   总被引:16,自引:0,他引:16  
介绍了美国著名生态学家H.T.Odum创立的能值理论,通过具体实例来分析环境- 能值特征,评价环境征税的经济价值,阐明自然环境与人类经济相互协调发 的重要性,为人们正确评价环境和从事科研提供新思路。  相似文献   
347.
不同预处理方式对不同类型土壤样品氮含量的分析结果具有不同程度的影响,尤其是对喀斯特流域石灰性土壤氮含量测定影响的相关研究较少,其影响程度和机理尚不清楚。本研究通过采集喀斯特流域乌江中上游四种不同土壤质地表层土壤(0~20 cm),对比了实验室内不同干燥方式和野外现场提取对氮含量测定结果的影响。结果发现石灰性土壤在干燥过程中,不同氮形态含量总体均表现出烘干土>风干土>新鲜土,表明烘干和风干过程会造成氮含量的测定结果相对于现场提取有不同程度的增加。在不同温度烘干过程中,NH+4-N和有机氮(Norg)的增加量与温度成正比,并且在不同的温度条件下可能受不同氮转化机理的控制,升温会促进土壤的矿化作用以及Norg的转化,而当温度较高(105℃)时,土壤中氮的增加还可能来自于微生物自身在高温条件下的分解;烘干过程中,不同温度处理下的NO-3-N含量之间没有明显差异,但均显著高于现场提取测定的结果,其中40℃下的烘干土中NO-...  相似文献   
348.
有机废弃物氢发酵制备生物氢气的研究   总被引:11,自引:1,他引:11  
在批式培养实验中以有机废弃物为原料,通过厌氧生物发酵制备生物氢气研究了菌种来源、有机废弃物种类对产氢能力的影响,以及生物氢发酵过程中液相组成的变化以活性污泥为菌种来源,以淀粉为底物,在30L改进的UASB反应器中进行了放大实验,生物气中氢气浓度达40%~51%,CO2浓度为49%~60%,且没有检测到甲烷气体,生物气经碱液吸收后氢气纯度大于97%持续产氢时间超过120d.  相似文献   
349.
TiO2/graphene oxide (GO) as photocatalyst in the photo-degradation of multitudinous pollutants has been extensively studied. But its low photocatalytic efficiency is attributed to the high band gap energy which lead to low light utilization. Cu-TiO2/GO was synthesized via the impregnation methods to enhance the catalytic performance. The Cu-TiO2/GO reaction rate constant for photo-degradation of pollutants (tetracycline hydrochloride, TC) was about 1.4 times that of TiO2/GO. In 90 min, the removal ratio of Cu-TiO2/GO for TC was 98%, and the maximum degradation ratio occurred at pH 5. After five cycles, the removal ratio of Cu-TiO2/GO still exceeded 98%. UV–visible adsorption spectra of Cu-TiO2/GO showed that its band gap was narrower than TiO2/GO. Electron paramagnetic resonance (EPR) spectra test illustrated the generation rate of ?O2? and ?OH was higher in Cu-TiO2/GO system than TiO2/GO and TiO2 system. The contribution sequence of oxidative species was ?O2? > holes (h+) > ?OH in both TiO2/GO and Cu-TiO2/GO system. Interestingly, the contribution of ?OH in Cu-TiO2/GO was less than that in TiO2/GO during the photo-degradation process. This phenomenon was attributed to the better adsorption performance of Cu-TiO2/GO which could reduce the accessibility of TC to ?OH in liquid. The enhanced non?hydroxyl radical contribution could be attributed to that the more other active species or sites on (nearby) the surface of Cu-TiO2/GO generated after doping Cu. These results provide a new perspective for the tradition metal-doped conventional catalysts to enhance the removal of organic pollutants in the environment.  相似文献   
350.
采用灰色关联法研究了巢湖流域产业结构与水污染之间的关系,查找分析对巢湖水质影响较大的行业,以期为巢湖水污染治理提供新思路.通过分析2001-2006年合肥市和巢湖市产业结构,表明合肥市在工业方面的电力、食品、冶金等行业对水污染影响较大;巢湖市对水污染的影响更多体现在牧业、渔业.因此,巢湖流域应加大产业结构调整,优化升级第一、第二产业内部结构,大力发展第三产业,以保护流域内水资源环境,促进流域区域经济社会可持续发展.  相似文献   
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