Fabrication of a prototype membrane filter for drinking water purification assisted by Comsol Multiphysics Simulations

Abstract

The emergence of new contaminants, owing to the persistently high levels of water pollution, has rendered most conventional water purification techniques inadequate and/or relatively costly. In this study, a simple, effective and affordable prototype membrane filter was fabricated, with the use of Comsol Multiphysics simulations. These simulations were used in the real-time prediction of the water-retention and lifetime of the fabricated membrane. The river and hand-dug well water samples filtered with the fabricated membrane filter, and the unfiltered samples were analysed using Laser Induced Fluorescence (LIF) and UV-Vis-NIR spectroscopy for Dissolved Organic Matter (DOM); Heterotrophic Plate Count (HPC) for microbes; and appropriate instruments for physico-chemical contaminants. Three (3) adsorbents; Hexa Decyl tri-Methyl Ammonium (HDMA) zeolite, Rice Husk Ash (RHA), and kaolin clay, were used in the membrane filtration tests, where their adsorptive properties were analysed and compared. The results showed a maximum DOM removal efficiency of 54.7 % for HDMA zeolite, 32.9 % for the RHA, and 10.3 % for kaolin clay in the Brimsu (BM) river water sample. The hand-dug well water samples, however, showed a better DOM removal efficiency (38.8 %) with the RHA than the HDMA zeolite (25.1 %). The results for colour, showed an efficiency of 96.6% for HDMA zeolite, 95.2 % for RHA and -3.4 % for kaolin clay. The Ag coated Polyurethane Foam (PUF) substrates, also showed a 100 % removal of Escherichia coli (E. coli) from all filtered samples. Hence, with the comparability of RHA to the relatively expensive HDMA zeolite, RHA was ranked as a potential adsorbent for drinking water purification.