TRANSPORT AND DEGRADATION OF TOXIC AGENTS IN BIOFILMS

生物膜中有毒物质的迁移和降解

• 批准号: 6340905
• 负责人: PAUL L BISHOP
• 金额: $ 17.11万
• 依托单位: UNIVERSITY OF CINCINNATI
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-04-01 至 2001-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6340905
• 关键词: aerobic bacteria; azo compounds; bioreactors; biotransformation; dyes; environmental toxicology; environmental transport; industrial waste; microelectrodes; microorganism culture; molecular film; organometallic compounds; waste treatment

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.

关于有毒物质的生物降解， 生物膜处理系统，特别是在机械水平。 是 这是非常重要的，因为许多材料构成了一个重要的 对公众健康构成威胁的污水不断排入我们的污水系统 却不知道他们的最终命运。 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，而不是生物膜法。 这是 不幸的是，由于大多数创新的治疗方法正在开发， 用于处理有毒废物的方法是基于生物膜的使用。 此外，本发明还提供了一种方法， 有一个缺乏知识的命运有机金属在任何 特别是在生物膜中。 这项研究计划的总体目标是研究生物降解 有毒有机物和有机金属的微生物生物膜， 评价污染物进出大气层的传输机制 生物膜，空间和定量表征微生物 生物膜中的种群，并将获得的结果应用于全- 水垢处理系统。 各种偶氮染料将被用作测试 有毒物质 最终的结果应该是一个更清晰的理解 生物膜处理系统的力学，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。 本研究的具体目的是：（1）表征生物膜， 关于生物膜密度，孔隙率，扩散率， 扩散层特性和微生物活性， 有毒物质的存在;（2）表征扩散边界层 在生物膜/液体界面处，其控制底物的量， 有毒物质和营养物质到达生物膜中的微生物; (3)评估偶氮的迁移机制和生物降解动力学 使用微电极和微切片技术 （4）确定降解偶氮染料的位置和数量 利用微电极和分子探针 对降解菌具有特异性;（5）评价接种的影响 好氧生物膜反应器与偶氮降解微生物;（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;和（7）评估微尺度结果的放大 到全尺寸。