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71.
72.
Akarsubasi AT Ince O Kirdar B Oz NA Orhon D Curtis TP Head IM Ince BK 《Water research》2005,39(8):1576-1584
Distribution and occurrence of Archaea and methanogenic activity in a laboratory scale, completely mixed anaerobic reactor treating pharmaceutical wastewaters were investigated and associated with reactor performance. The reactor was initially seeded with anaerobic digester sludge from an alcohol distillery wastewater treatment plant and was subjected to a three step feeding strategy. The feeding procedure involved gradual transition from a glucose containing feed to a solvent stripped pharmaceutical wastewater and then raw pharmaceutical wastewater. During the start-up period, over 90% COD removal efficiency at an organic loading rate (OLR) of 6 kg COD m(-3)d(-1) was achieved with glucose feeding, and acetoclastic methanogenic activity was 336 ml CH4 gTVS(-1)d(-1). At the end of the primary loading, when the feed contained solvent stripped pharmaceutical wastewater at full composition, 71% soluble COD removal efficiency was obtained and acetoclastic methanogenic activity decreased to half of the rate under glucose feed (166 ml CH4 gTVS(-1)d(-1)). At the end of secondary loading with 60% (w/v) raw pharmaceutical wastewater, COD removal dropped to zero and acetoclastic methanogenic activity fell to less than 10 ml CH4 gTVS(-1)d(-1). Throughout the course of the experiment, microbial community structure was monitored by DGGE analysis of 16S rRNA gene fragments. Five different archaeal taxa were identified and the predominant archaeal sequences belonged to methanogenic Archaea. Two of these showed greatest sequence identity with Methanobacterium formicicum and Methanosaeta concilii. The types of Archaea present changed little in response to changing feed composition but the relative contribution of different organisms identified in the archaeal DGGE profiles did change. 相似文献
73.
禁忌模拟退火复合形法及其在边坡稳定性分析中的应用 总被引:3,自引:0,他引:3
对于随机生成的初始复形,首先,选取与其他顶点相似程度最大的顶点进行禁忌退火操作,禁忌退火产生新顶点的区域限于该点和其余各顶点的中心点连线上,若关于该点的禁忌退火没有产生新的顶点,即禁忌退火失败,则选取与其他顶点相似程度次大的顶点进行退火,直至关于复形全部顶点的退火操作均失败;然后,对当前的复形进行改进的复合形法计算,采用与基本复合形法类似的映射收缩算子迭代至收敛。禁忌模拟退火复合形法不仅考虑了目标函数的改进,而且保持了各项点的多样性,避免了基本复合形法容易陷入局部极优的缺点。对2个非均质土坡的临界滑动面进行搜索表明,该方法具有较高的寻优成功率。 相似文献
74.
An electrochemical model for an upflow dual-chambered microbial fuel cell (MFC) process is proposed in this study. The model was set up on the basis of the experimental results and the analysis of biochemical and electrochemical processes in the MFC biocatalysed with anaerobic aged sludge and alternatively fuelled with a synthetic acetate-based and actual domestic wastewaters. Simulation of the process shows that the model describes the process reasonably well with correlation coefficients higher than 0.97. The analysis of model simulation illustrates how the current output depends mainly on the substrate concentration as well as other main variables. The relationship between the current output and over-voltage is revealed by the modelling study. For acetate-based wastewaters with initial chemical oxygen demand (COD) concentrations of 350, 700, 1050, and 1400 mg/L, maximum observed power densities were 290, 405, 448, and 525 mW/m2 associated with maximum COD removals of 84%, 88%, 83%, and 82%, respectively. 相似文献
75.
Humic acid, which is a typical microbially refractory organic substance, was extracted from a landfill leachate. The humic acid solution (COD = 367 mg 1−1; TOC = 293 mg 1−1; BOD = 27 mg 1−1) was applied to a batch scale activated sludge treatment after the modification of its biodegradability by γ-ray irradiation. The BOD increased to 64 mg 1−1 by irradiation of 15 kGy (1.5 Mrad), while the COD and TOC decreased to 231 and 230 mg 1−1, respectively. When the irradiated sample was treated with an activated sludge, the BOD decreased rapidly in 2–3 h to about 15 mg 1−1 which was a similar value as the unirradiated sample was treated. The elimination efficiency of TOC by the sludge treatment was approximately equal to that obtained by irradiation of 15 kGy. These facts suggest a utility of applying microbial processes after radiation treatment of microbially refractory wastewaters. 相似文献
76.
SSCP技术在微生物群落监测中的应用 总被引:1,自引:0,他引:1
综述了应用单链构象多态性技术(SSCP)对微生物群落进行分析的基本过程,以及在模式微生物群落、人工与自然群落结构和动态分析中的应用。并针对SSCP技术存在的问题提出了一些改进建议,指出在进行复杂微生物群落分析时,应采用含有甘油的高比率凝胶(丙烯酰胺∶双丙烯酰胺>49∶1)和低pH值(7.7)的TBE电泳缓冲液,并以λ核酸外切酶将PCR产物中的反意义链去掉以减少大量非特异带的出现,提高技术的分辨率。另外,该技术在SSCP条带的菌种唯一性和纯培养标记等方面还有待改进。 相似文献
77.
就上海市衡山—复兴路组的淮海路段进行了城市设计实地调查,从凯文.林奇的城市意象的五个元素入手,以整体性、多样性为出发点对其进行分析和评价,最后提出相应的城市设计措施。 相似文献
78.
以学科交叉的方法,运用复杂适应性系统理论来分析校园集群形态的复杂性,探讨如何解决校园集群的动态演进和规划方案的终极一元静止性之间的矛盾,提出了弹性控制的校园规划理念。以拓展校园规划设计的思路。 相似文献
79.
Recent work in the US has shown that contact between lubricants and oils and drinking water can promote the growth of heterotrophic micro-organisms. It is unlikely that these species are pathogenic, and therefore harmful to man. However, the hygienic status of water distribution systems could be affected, leading to higher heterotrophic plate counts during routine sampling. Experimental work has been undertaken to study the microbiological impact of a range of lubricants and oils on drinking water. The methods have been based on an existing procedure for the assessment of the growth potential of drinking water, i.e. the 'assimilable organic carbon'test. The results of this work could serve as the basis of a future standard method for the rapid and inexpensive screening of oils and lubricants for their microbiological suitability in potable-water applications. 相似文献
80.
Mixed microbial films were grown on the inner walls of a tubular reactor with recirculation of the reactor contents and continuous flow-through of nutrient solution. The loss of total oxidized nitrogen was correlated to the film population, the nitrite concentration and the dissolved oxygen concentration in the reactor. When film population was greater than 0.5 × 109 cells cm−2, reactor dissolved oxygen concentration greater than 1 mg l−1 had little effect on the nitrate loss. Nitrate loss declined for film populations greater than 2 × 109 cells cm−2. Models based on Monod and zero-order microbial kinetics were calibrated using these data and a nonlinear least squares method. There was little difference in the residual errors with these methods. 相似文献