RUI: Modeling of Sludge Dewatering Processes

该项目的目标是改进设计用于从污泥中除水的设备和工艺的工艺。这将涉及开发全尺寸脱水设施的基于计算机的模拟模型，以实现具有成本效益的设计和确定操作条件的能力，以最大限度地提高脱水效率。理论方法将包括对带式压滤机的物理模型进行建模，其中包括重力沉降、横向无约束区域中的滤饼过滤、考虑二次固结或蠕变的影响、滤饼去除机制和带式洗涤效率。带式压滤机的综合模型预计将由实验室推导的污泥孔隙度与有效应力和渗透率的函数关系驱动。这些关系将通过检查比阻力和压缩渗透率单元数据来确定。该模型将使用比例模型压滤机的数据进行测试，该模型使用可重复使用的高岭土悬浮液。进一步的模型测试将使用波特兰市的全尺寸带式压滤机来分析模型预测厌氧消化污泥脱水特性的能力。预计该项目的成果将用于改进目前设计污泥脱水系统的做法，污泥的处理和管理约占废水处理成本的一半。

The objective of this project is to improve the process by which equipment and processes are designed for removing water from sludges. This will involve the development of computer based simulation models of full-scale dewatering facilities that will enable cost- effective design and the ability to identify operational conditions to maximize dewatering efficiency. Theoretical approaches will include modeling the physics of the belt filter press which involves gravity sedimentation, cake filtration in a laterally unconfined domain incorporating the effect of secondary consolidation or creep, cake removal mechanisms, and belt washing efficiency. The integrated model of the belt filter press is expected to be driven by laboratory derived relationships of sludge porosity as functions of effective stress and permeability. These relationships will be determined by examining specific resistance and compression- permeability cell data. The model will be tested with data from a scale model filter press using a reproducible suspension of kaolin. Further model testing will be accomplished using the city of Portland's full-scale belt filter presses to analyze the model's ability to predict dewatering characteristics of an anaerobically digested sludge. Results of this project are expected to be used in improvements of current practice in designing systems for dewatering sludges, processing and management of which are approximately half the cost of wastewater treatment.