Removal of Cu(II) from aqueous solution by iron vanadate: equilibrium and kinetics studies

Iron vanadate (FeVO4) was synthesized by a co-precipitation method and was firstly used as an adsorbent for the removal of Cu2+ from aqueous solution. The effects of operating parameters on the adsorption of Cu2+ by FeVO4 such as contact time, temperature, solution pH and initial concentration of Cu2+ were investigated. Kinetic study exhibited that the adsorption of Cu2+ onto FeVO4 followed a pseudo-second-order model and was controlled by the film diffusion with a small contribution of intraparticle diffusion. The equilibrium data could he well fitted with the Langmuir isotherm, indicating a monolayer adsorption process. The mean free energy E (kJ mol(-1)) got from the D-R isotherm also suggested the chemisorption nature of the adsorption process. The desorption study showed that 95% and 98% of Cu2+ was desorbed from FeVO4 using 0.1 M of HNO3 and 0.1 M of EDTA, respectively. Moreover, the maximum adsorption capacity of FeVO4 toward Cu2+ is 55.6 mg g(-1) at pH 5.0, which is higher than most of the adsorbents reported in the same pH range. The results indicate that FeVO4 is a promising adsorbent for the removal of Cu2+ from waste effluents.