Humic acid (HA) modifying Fe3O4 nanoparticles (Fe3O4/HA) was developed for removal of Rhodamine B from water. Fe3O4/HA was prepared by a coprecipitation procedure with cheap and environmentally friendly iron salts and HA. TEM images revealed the Fe3O4/HA (with ~10nm Fe3O4 cores) were aggregated as aqueous suspensions. With a saturation magnetization of 61.2emu/g, the Fe3O4/HA could be simply recovered from water with magnetic separations at low magnetic field gradients within a few minutes. Sorption of the Rhodamine B to Fe3O4/HA reached equilibrium in less than 15min, and agreed well to the Langmuir adsorption model with maximum adsorption capacities of 161.8mg/g. The Fe3O4/HA was able to remove over 98.5% of Rhodamin B in water at optimized pH.
- Rhodamine B