| iquid-particle separation in potable water treatment involves a wide range of techniques broadly divided into sedimentation and filtration. The main purposes of separation are to decrease waterborne disease through reduction in the number of harmful microorganisms and to increase aesthetics through reduction of suspended solids. The general objective of this research work was to study possible applications for textile materials in water treatment. The specific objective was to enhance water treatment filter operations by the use of a nonwoven textile material.;This research project involved the following five components: a review of literature; a laboratory research program which involved developing equipment and a testing protocol for short term laboratory testing; the screening of a number of commercial geotextile fabrics as filter media with influents selected from various plant operational sites; a continuous field pilot in a municipal water treatment plant with one needlefelt, nonwoven, polypropylene fabric as the filter media; and the development of a qualitative model to explain the particle removal processes.;Data collection included particle counting, turbidity measurements, pH, temperature, and head loss measurements. Analysis of data included routine numerical analysis, scanning electron microscopy and zeta potential measurements.;Field testing involved the removal of predominantly calcium carbonate particles from the contact basin prior to sand filtration. This research shows that a nonwoven fabric with openings of 150 mum can successfully remove a fraction of particles less than 10 mum. Particle removal occurred through surface attachment with the accumulation of small particles. Entrapment of particles between over lapping fibers and the attachment of particles on rough areas on fiber filaments also occurred. The dominant mechanism of removal in the filter was particle-to particle attachment.;There was sufficient removal performance for these textiles to be of interest as a potential medium for removal of 4 to 10... |
