Castor seeds hull activated carbon impregnated with silver nanoparticles for removal of Escherichia coli from water
Ibsa Neme, Girma Gonfa, Chandran Masi
Abstract
Disinfection is key process in municipal water supply process. In this work, silver nanoparticles (AgNPs) were impregnated on activated carbon (AC) prepared from castor seed hull and used for disinfection of water. The AC and AgNPs-impregnated AC (AC-AgNPs) were characterized using Fourier transform infra-red (FT-IR), Brunauer–Emmett–Teller (BET), X-ray diffraction (XRD), scanning electron microscope-energy dispersive spectroscopy (SEM-EDX) to confirm the functional groups, morphology and the presence of silver nanoparticles on the activated carbon. A maximum 0.0427 wt% AgNPs loading was observed for AC treated with 100 mL AgNPs colloid solution and 32 h impregnation time. The maximum BET surface area of AC-AgNPs was 697.54 m2/g found for AC-AgNPs treated with 25 mL AgNPs colloid solution for 8 h. The disinfection performances of the AC-AgNPs on Escherichia coli (E. coli) were investigated through batch and continuous studies. In the batch study, the concentration of E. coli was reduced from 5.6 × 107 to 0.0 in 20 min for AC-AgNPs while no significant changes were observed for non-impregnated AC. Finally, the disinfected water was tested for AgNPs leaching with UV–vis and no AgNPs UV peak was observed.