Development and evaluation of a low-cost ceramic filter for the removal of methyl orange, hexavalent chromium, and Escherichia coli from water

Abstract

Lack of safe drinking water gives rise to waterborne diseases and other human health risks caused by various pollutants. Safe water provision in low-income countries is constrained by limited financial resources, and the problem is worsened during natural disasters. Thus, there is need to develop efficient low-cost technologies for point-of-use water treatment. Filtration using ceramic filters is a viable method as it uses locally available clay and biomass. The aim of this work was to develop and fabricate a laboratory-scale ceramic filter for water treatment, and to evaluate its capacity to remove Cr(VI), methyl orange (MO), and Escherichia coli 0157:H7 from water. Locally sourced clay and sawdust (SD) were used to fabricate filters with varying sawdust contents of 0, 2.5, 5, 10 and 30% (w/w). The clay-sawdust composites were fired in a muffle furnace at a heating rate of 200 °C/h up to 600, 750, and 900 °C for 3 h. Then the clay filter (CF) with the highest permeability was impregnated with silver nanoparticles (AgNP) to produce AgNP-CF. The surface charge, functional groups, surface morphology, and crystallinity of the filters were determined using the pH-drift method, Fourier transform infrared spectrometry, scanning electron microscopy, and X-ray powder diffraction, respectively. The permeability increased with biomass content and firing temperature. The AgNP-CF removed 57.3, 69.1, and 100% of Cr(VI), MO, and E. coli, respectively. Overall, the study demonstrated that AgNP-CF can potentially be used for water treatment in low-income communities.