Density of coliform bacteria in well water filtered using a filter coated with silver nanoparticles

Abstract

Abstract. Mufidah LN, Setyono P, susilowati A. 2021. Density of coliform bacteria in well water filtered using a filter coated with silver nanoparticles. Asian J Trop Biotechnol 18: 32-36. The poor filtration process causes low water quality due to coliform bacteria. Today's nanoparticle technology is growing, one of which is silver nanoparticles known to have antimicrobial properties. Silver nanoparticles can be an alternative for making water filters while also killing bacteria. Therefore, this study was conducted to see the density of coliform bacteria in well water filtered using a filter coated with silver nanoparticles. It is an experimental study with five significant steps: synthesis of silver nanoparticles via reduction, coating filter paper with silver nanoparticles via the shake flask method, water filtration, bacterial density determination via the Most Probable Number (MPN) method, and coliform bacteria viability determination. The main parameter observed in this study was the density of coliform bacteria in well water through a filtering process, namely the MPN value. The synthesis of silver nanoparticles in the form of a gray-green-brown colloidal solution was formed at a wavelength of 437 nm. Silver nanoparticles can stick to the filter paper, which will be used for filtering, indicated by the change in the color of the paper to grayish brown. The MPN value of the control group in all wells was >1,100/100 mL, while the treatment group's wells were 1,2,3, 9.05; 553.65; and 1.5/100 mL. The t-test analysis of the MPN value showed a significant difference between the control and treatment groups with a significance value of <0.05, i.e., 0.04. The coating of silver nanoparticles on the water filter also killed coliform bacteria, which was indicated by the absence of bacteria growth from the filter paper used. The density of coliform bacteria in well water filtered using a filter coated with silver nanoparticles was lower than the control (without silver nanoparticle coating).