Development of Soil Filter Design Nomograms Incorporating Physicochemical and Biological Mechanisms

现有的土壤过滤器设计标准主要基于颗粒保留原则，通常涉及过滤器和基础土壤的粒径分布的比较，并且没有考虑与胶体大小的细颗粒运输相关的过滤器堵塞。本研究解决了需要一个全面的理解和方法发展的设计过滤器结合物理化学和生物机制。在过滤和生物膜理论的最新进展将被利用在拟议的研究从基本原则发展设计图。具体来说，这些项目的目标是：1)系统地进行实验评价孔隙流体的物理化学和生物学特性暂停对土壤过滤器堵塞,2)开发和验证一个数学模型,定量预测的程度土壤堵塞过滤介质的物理化学和生物学特性和孔隙流体悬浮,和3)在设计模式中使用的模型和生成容易可用列线图设计土壤过滤器。实验调查将包括两个阶段。在第一阶段，生物活性将被抑制，物理化学特性(如过滤介质特性（颗粒和孔径分布、空隙比）和孔隙流体组成（以离子强度/pH值衡量）的影响将被系统地评估。在第二阶段，将引入细菌菌株，并评估底物浓度和溶解氧对生物量生长的影响。实验中的过滤介质将在测试结束时进行彻底的表征，以确定颗粒和生物堵塞的程度。在实验过程中，将对进水和出水进行连续监测。所有用于模型开发和验证的信息都将从实验中产生。最后，本研究将利用正在进行的失效调查在韩国元州垃圾填埋场渗滤液收集系统。与韩国团队的相互合作将为验证研究和开发的设计工具提供必要的实地视角。

Existing criteria for soil filter design are based largely on particle retention principles, often involving comparison of particle size distributions of filter and the base soils, and do not account for filter clogging associated with the transport of colloid-sized fine particles. This research addresses the need for a comprehensive understanding and methodology development for design of filters incorporating physicochemical and biological mechanisms. Recent advances in filtration and biofilm theories will be exploited in the proposed research to develop design nomograms from fundamental principles. Specifically, the goals of the projects are: 1) to systematically perform an experimental evaluation of the role of physicochemical and biological characteristics of pore fluid suspension on soil filter clogging, 2) to develop and validate a mathematical model that quantitatively predicts the extent of soil clogging in terms of physicochemical and biological characteristics of the filter media and the pore fluid suspension, and 3) to use the model in a design mode and generate easily usable nomograms for designing soil filters. The experimental investigation will include two stages. In the first stage, biological activity will be suppressed and the effect of physicochemical characteristics such as the filter medium properties (particle and pore size distributions, void ratios) and the pore fluid composition (measured in terms of ionic strength/pH) will be assessed systematically. In the second stage, bacterial strains will be introduced and the effects of substrate concentrations and dissolved oxygen on biomass growth will be assessed. The filter medium in the experiments will be thoroughly characterized at the end of testing to determine the extent of particulate and biological clogging. The influent and effluent will be monitored continuously during the experiments. All information for model development and validation will be generated from the experiments. Finally, the study will take advantage of ongoing failure investigation on the Won-Ju landfill leachate collection system in Korea. The mutual collaboration with the Korean team will provide the field perspective necessary for validation of the research and the developed design tools.