A holistic optimization framework for improving ceramic pot filter performance

Abstract

Ceramic pot filters (CPFs) are a promising low-cost option for household water treatment, providing a barrier of protection against microbiological contaminants for households with or without reliable piped water supplies. However, as an open-source design, performance of CPFs is not standard across manufacturers and at times can be suboptimal. Furthermore, no scientific study has provided a holistic framework for optimizing filter performance. The goal of this paper is to provide CPF manufacturers with tools to increase their ability to reach performance objectives for flow rate, bacteria removal and strength. This goal is achieved by experimentally determining relationships between performance and three manufacturing parameters: percentage rice husk, rice husk size and wall thickness. These results are translated into design and manufacturing recommendations, which are as follows: 1) tightly control rice husk size to maintain consistent flow rates; 2) maximize wall thickness within the constraints in order to improve bacteria removal; 3) seek alternative methods of increasing bacteria removal if removal levels greater than 2LRV are needed. To go further and provide a more quantitative and universal optimization framework, we then use the identified functional relationships between the manufacturing parameters and filter performance to formulate a single-criterion optimization. This framework enables manufacturers to determine an ideal combination of manufacturing parameters based on the specific situation of each manufacturing site. The systematic approach to CPF design presented in this paper can be further extended to address additional manufacturing parameters and aspects of filter performance to further improve the CPF design. This work has huge potential to better serve the many people around the world who lack safe drinking water.