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931.
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N-acyl-homoserines quenching, enzymatic quenching of bacterial quorum sensing, has recently applied to mitigate biofilm in membrane bioreactor. However, the effect of AHLs on the behavior of biofilm formation is still sparse. In this study, Pseudomonas aeruginosa biofilm was formed on ultra-filtration membrane under a series of N-(3-oxooxtanoyl)-L-homoserine lactone (C8-oxo-HSL) concentrations. Diffusing C8-oxo-HSL increased the growth rate of cells on biofilm where the concentration of C8-oxo-HSL was over 10-7 g/L. The C8-oxo-HSL gradient had no observable influence on cell density and extracellular polymeric substances of biofilm with over 10-7 g/L C8-oxo-HSL. Surprisingly, 10-11-10-8 g/L of C8-oxo-HSL had no effect on cell growth in liquid culture. The cell analysis demonstrated that the quorum sensing system might enhance the growth of neighboring cells in contact with surfaces into biofilm and may influence the structure and organization of biofilm. 相似文献
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Al13 or Alb is usually regarded as the most efficient species of polyaluminum chloride(PAC), the performance flocculant for water treatment. This paper was intended to report a new method to synthesize PAC with high content Alb, by using the membrane reactor. NaOH solutions were managed to permeate slowly through the micropores of ultrafiltration membrane into AlCl3 solutions under the suitable transmembrane pressure(TMP). Meanwhile NaOH drops size was limited to nano-scale, resulting in dramatical reduction of the characteristic diffusion time and great increment of contact interface between the strong base and AI ions in solution to favor the formation of Al(OH)4^-, the precursor of AI,3, so few precipitates and much Alb are produced. When the initial concentration of AlCl3/NaOH is 0.40/2.0 (mol/L), MWCO = 10000, TMP = 0.0085 MPa, T= 305 K and B(molar ratio of OH^-/Al^3 ) = 2.25, the quantity of Alb attains about 80%. The results of ^27Al-NMR determination showed that the Al13 content is equal to Alb content. And our PAC product has shown better flocculation effects than the commercial product. 相似文献
936.
Qian Li Zhaoyang Hou Xingyuan Huang Shuming Yang Jinfan Zhang Jingwei Fu Yu-You Li Rong Chen 《Frontiers of Environmental Science & Engineering》2023,17(6):68
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提出在采用浸入物体法(IOM)对膜结构和空气流体建模时,可以采用带有预定条件的无矩阵Newton-Krylov迭代算法求解浸入物体法,并引入了预定条件矩阵。将提出的无矩阵迭代方法应用于一双坡型膜结构的风振耦合分析中,得出了结构的风压和风速分布,并对带有预定条件和不带预定条件的无矩阵迭代算法进行了对比。结果表明,将带有预定条件的无矩阵迭代算法应用于膜结构风振的耦合分析中,可以得到准确结果,并使计算效率大大提高。 相似文献
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In the recent years a group of contaminants, known collectively as emerging contaminants (ECs), have attracted considerable attention due to their widespread in the environment, and lack of knowledge on their impacts on ecosystem and human health. This review gives an overview on the sources, impacts, and conventional treatment technologies of ECs and an in-depth review of the literature on the state-of-the-art treatment technologies and their performance in the removal of ECs from water sources and drinking water. A careful statistical analysis of the number of publications on the different treatment technologies of ECs was performed to identify the hot spots in this research area. Conventional treatment technologies are not able to remove ECs sufficiently. The discharge of raw or partially treated wastewater is the main source of ECs in the environment. The research in recent years is focusing on using advanced treatment process (AOPs), followed by adsorption and membrane technologies. From a technical point of view, AOPs surpass other treatment technologies as they can completely eradicate ECs without the generation of side products. Developing efficient, green, and cost-effective materials to be used as adsorbents, photocatalysts, membranes, or membrane fillers, is one of the main research trends nowadays. Combined AOPs based on exploiting solar light, ultrasound and electrochemistry are gaining growing interest and show high potential for the treatment of ECs. 相似文献