Assessment of carbon nanotubes and silver nanoparticles loaded clays as adsorbents for removal of bacterial contaminants from water sources

• Published in: Journal of water and health 2017-02, Vol.15 (1), p.133-144
• Main Authors: Hassouna, M E M, ElBably, M A, Mohammed, Asmaa N, Nasser, M A G
• Format: Article
• Language: English
• Subjects: Adsorbents; Adsorption; Analytical methods; Antiinfectives and antibacterials; Antimicrobial agents; Bacteria; Bacteria - isolation & purification; Carbon; Carbon nanotubes; Chemical vapor deposition; Clay; Contaminants; Disinfection & disinfectants; Drinking water; Drinking Water - microbiology; E coli; Effectiveness; Electron microscopy; Feasibility studies; Feces; Fluorescence; Kaolin; Kaolin - chemistry; Metal Nanoparticles - chemistry; Microorganisms; Nanomaterials; Nanoparticles; Nanotechnology; Nanotubes; Nanotubes, Carbon - chemistry; Organic chemistry; Organic contaminants; Pathogenic bacteria; Pathogens; Removal; Salmonella; Silver; Silver - chemistry; Spectroscopy; Surface water; Transmission electron microscopy; Waste Disposal, Fluid - instrumentation; Waste Disposal, Fluid - methods; Waste Water - microbiology; Wastewater; Water analysis; Water Microbiology; Water pollution; Water Purification - instrumentation; Water Purification - methods; Water quality; Water sampling; Water supply; Water treatment; X ray spectra; X-ray fluorescence
• ISSN: 1477-8920; 1996-7829
• DOI: 10.2166/wh.2016.304

This work evaluated the antimicrobial efficacy of kaolin clay and its loaded forms with carbon nanotubes (CNTs) and silver nanoparticles (AgNPs) against bacterial isolates from different water supplies (tap, underground and surface water) in addition to wastewater. A total of 160 water samples were collected from different water sources in the investigated districts. Samples were cultured for isolation and serological identification of pathogenic bacteria. AgNPs were synthesized by a typical one-step synthesis protocol, where CNTs were carried out in a reactor employing the double bias-assisted hot filament chemical vapor deposition method. Both were characterized using transmission electron microscopy, infrared and X-ray fluorescence (XRF) spectroscopy. The antimicrobial efficacy of each of natural kaolin clay, AgNPs- and CNTs-loaded clays were evaluated by their application in four concentrations (0.01, 0.03, 0.05 and 0.1 ppm) at different contact times (5 min, 15 min, 30 min and 2 h). AgNPs-loaded clays at concentrations of 0.05 and 0.1 mg/l for 2 h contact time exhibited a higher bactericidal efficacy on Escherichia coli and Salmonella spp. (70, 70, 80 and 90%, respectively) compared to CNTs-loaded clay. Concluding, the application of AgNPs-loaded clay for removal of water bacterial contaminants at a concentration of 0.1 ppm for 2 h contact times resulted in highly effective removals.