TRANSPORT AND DEGRADATION OF TOXIC AGENTS IN BIOFILMS

关于有毒物质的生物降解，人们知之甚少 生物膜处理系统，特别是在机械层面。它是 具有至关重要的意义，因为许多材料构成了显著的 公共健康威胁不断排放到我们的污水系统中 对他们的最终命运一无所知。几乎所有关于 有毒物质的生物降解是使用悬浮生长系统进行的，例如 活性污泥法，而不是在生物膜中。这是 不幸的是，由于正在开发的大多数创新的治疗工艺 用于处理有毒废物的技术是基于生物膜的使用。此外, 对于有机金属的命运，人们缺乏了解。 媒体，但特别是在生物膜。 这项研究计划的总体目标是研究生物降解。 微生物生物膜中有毒有机物和有机金属的研究 评价污染物进出的传输机制 生物膜，空间和定量表征微生物 生物膜中的种群，并将所获得的结果应用于完全- 结垢处理系统。各种偶氮染料将被用作测试 有毒物质。最终的结果应该是更清楚地理解 生物膜处理系统的机制，允许更准确地 设计处理有毒废物的工艺，从而保护和 保护人类健康和环境。 这项研究的具体目的是：(1)用 关于生物膜密度、孔隙率、扩散率、 内、外扩散层特性及微生物活性 毒物的存在；(2)描述扩散边界层 在控制底物数量的生物膜/液体界面， 到达生物膜中微生物的有毒物质和营养物质； (3)研究了偶氮染料的迁移机理和生物降解动力学。 利用微电极和微切片法研究生物膜中的染料 技术；(4)确定偶氮染料降解的位置和数量 利用微电极和分子探针研究生物膜中的微生物 针对降解菌；(5)播种效果评价 降解偶氮菌的好氧生物膜反应器；(6)评价 有毒金属的迁移机制和生物降解动力学 络合偶氮染料；以及(7)评价微尺度结果的放大 到全尺寸。

Little is known concerning the biodegradation of toxic materials in biofilm treatment systems, particularly at the mechanistic level. It is of vital importance because many materials which pose a significant public health threat are continually discharged into our sewage systems without knowledge of their ultimate fate. Nearly all research on biodegradation of toxics is done using suspended growth systems, such as the activated sludge process, rather than in biofilms. This is unfortunate, since most innovative treatment processes being developed for treating toxic wastes are based on the use of biofilms. In addition, there is a dearth of knowledge on the fate of organo-metallics in any media, but particularly in biofilms. The overall goals of this research program are to study biodegradation of toxic organics and organo-metallics in microbial biofilms by evaluating transport mechanisms of contaminants into and out of the biofilm, spatially and quantitatively characterizing the microbial populations in the biofilm, and applying the results obtained to full- scale treatment systems. A variety of azo dyes will be used as the test toxic substances. The end result should be a much clearer understanding of the mechanics of biofilm treatment systems, allowing for more accurate design of processes for treating toxic wastes, and thus protecting and preserving human health and the environment. Specific aims of the research are to: (1) characterize the biofilms with respect to variations in biofilm density, porosity, diffusivity, diffusion layer characteristics and microbial activity in and without the presence of the toxicant; (2) characterize the diffusion boundary layer at the biofilm/liquid interface, which controls the amount of substrate, toxic materials and nutrients reaching the microorganisms in the biofilm; (3) evaluate transport mechanisms and biodegradation kinetics for the azo dyes in the biofilms using microelectrodes and a micro-sectioning technique;(4) determine the location and number of azo dye-degrading microorganisms in the biofilms using microelectrodes and molecular probes specific for the degradative bacteria; (5) evaluate the impact of seeding aerobic biofilm reactors with azo-degrading microorganisms; (6) evaluate transport mechanisms and biodegradation kinetics for toxic metal- complexed azo dyes; and (7) evaluate the scale-up of micro-scale results to full-scale.