Preliminary evaluation of natural fabrics in slow sand filtration

Previous research at Imperial College, London, UK has shown that slow sand filters protected by layers of synthetic fabrics have increased run times compared to un-protected slow sand filters by a factor of up to 8. This was achieved by the application of fabric layers on the surface of the filter. The study presented in this paper has been concerned with replicating these findings through the use of natural fabrics, to make available the advantages of protected slow sand filtration to developing countries utilising local materials and/or minimising the use of foreign exchange. In this study it has been found that through the application of nonwoven fabrics made of jute, the run time of pilot-scale slow sand filters can be extended. The use of natural materials also introduces new aspects that will require further investigation, such as fibre degradation, release of nutrients and methods of fabric cleaning.