Anaerobic mixed consortium (AMC) mediated enhanced biosynthesis of silver nano particles (AgNPs) and its application for the removal of phenol

In this research, silver nano particle (AgNP), was synthesized through a novel anaerobic mixed consortium
mediation method and applied for the removal of phenol. The best operating conditions for the fabrication of
silver nanoparticles were identified through response surface methodology (RSM) and the maximum yield was
found to be 2.65 g/100 ml of anaerobic mixed consortium at optimal conditions of pH-8.6, temperature-90 ◦C,
silver nitrate concentration-3 mg/ml and inoculum volume-3 ml. The synthesized nano particle exhibited a
maximum phenol removal of 87.65% was achieved at pH:5.8. The synthesized silver nanoparticles were characterized
by superior surface area (19.26 m2/g) and the stability was confirmed by thermo gravimetric analysis
(upto 500 ◦C). The surface morphology was well explained using High Resolution Transmission Emission Microscopy
(HR-TEM) and Scanning Electron Microscope with EDS (SEM-EDS) techniques. X-ray Diffraction (XRD)
analysis confirmed the changes in crystalline structure due to the adsorption of phenol. Kinetic experiments fitted
well with the intra-particle diffusion model. The nature of adsorption of phenol was confirmed as monolayer by
the goodness of fit with Langmuir isotherm (R2 > 0.9969).