BIOAVAILABILITY, SOIL HETEROGENEITY, AND BIODEGRADATION OF ORGANIC CONTAMINANTS

描述：这个项目的目的是增进我们对 土壤异质性和速率限制的影响 生物降解与原位生物修复中的吸附/解吸 地下系统中的有机污染物。具体的目标是 在这项拟议的研究中将解决的问题是：1)调查 物理异质性(“优先流”和微观非均质性)的影响 孔/大孔传质)对生物降解位置和速率的影响 运输过程中；2)调查接触时间(之间)的影响 污染物和土壤)和限速解吸对生物有效性的影响； 3)建立模拟生物降解的数学模型，速率- 有限吸附/解吸扩散传质和传质 非均质多孔介质。提出了一种新的表征方法 物性(孔径分布、非均质性对流体的影响 运输)、化学(吸附程度的速率)和微生物 (细菌的位置、浓度和活性)土壤的性质 包含在用于测量污染物传输的柱中。这 该方法结合了流动和传输表征技术(水- 保留功能、示踪剂传输、染料染色)具有吸附功能 用于表征自然和环境的测量和先进技术 细菌数量(放射性标记细胞、基因探针)。这 方法将使他们能够将土壤异质性的影响联系起来 论水流运动对土壤非均质性的影响 对吸附/解吸的影响以及生物降解的位置和速度。

Description: The goal of this project is to enhance our understanding of the effects of soil heterogeneity and rate-limited sorption/desorption on biodegradation and in-situ bioremediation of organic contaminants in subsurface systems. The specific objectives that will be addressed in this proposed research will be to: 1) investigate the influence of physical heterogeneity ("preferential flow" and micro- pore/macro-pore mass transfer) on location and rate of biodegradation during transport; 2) investigate the effect of contact time (between contaminant and soil) and rate-limited desorption on bioavailability; 3) develop mathematical models for simulating biodegradation, rate- limited sorption/desorption diffusive mass transfer and transport in the heterogenous porous media. A novel approach is proposed to characterize the physical (pore-sized distribution, impact of heterogeneity on fluid transport), chemical (rate in extent of sorption), and microbiological (location, concentration, and activity of bacteria) properties of soil contained in the columns used to measure contaminant transport. This approach combines flow and transport characterization techniques (water- retention function, tracer transport, dye staining) with sorption measurements and advanced techniques for characterizing the nature and quantity of bacteria population (radio-label cells, gene probe). This approach will allow them to correlate the impact of soil heterogeneity on flow and transport to the impact of soil heterogeneity on the rate of sorption/desorption and on the location and rate of biodegradation.