Adsorption of phosphorus onto nanoscale zero-valent iron/activated carbon: removal mechanisms, thermodynamics, and interferences

Abstract This study investigated removal mechanisms, thermodynamics, and interferences of phosphorus adsorption onto nanoscale zero-valent iron (nZVI)/activated carbon composite. Activated was successfully used as support for nZVI particles to overcome shortcomings using include its tendency aggregate separation difficulties. A comprehensive characterization done the composite particles, which revealed a high specific surface area 72.66 m2/g an average particle size 37 nm. Several isotherms kinetic models have been applied understand mechanisms. Adsorption isotherm is best fitted by Freundlich Langmuir models, indicates that estimated maximum capacity 53.76 mg/g at pH 4. kinetics showed chemisorption process behaved according pseudo-second-order model. An mechanism conducted intra-particle diffusion Boyd indicated rate limited diffusion. thermodynamic efficiency increased solution temperature from 15 °C. Finally, results interference presence Ni2+, Cu2+, Ca2+, Na+ cations, nitrate ions (), sodium acetate improves efficiency, while sulfate () urea reduces efficiency.