Packed bed column adsorption characteristics of Arsenic (V) on polyacrylamide cryogel containing iron hydroxideoxide nanoparticles

Polyacrylamide(PAA) cryogels containing iron hydroxide oxide(FeOOH) nanoparticles were prepared and used for the fixed bed continuous adsorption of As(V) from water. The effect of inlet As(V) concentration and feed flow rate on the breakthrough characteristics of the fixed bed continuous adsorption were investigated. The cryogels have a large number of pores with μm order and FeOOH nanoparticles are observed on the surface and inside of the wall of the cryogels. Hence it was found that As element was observed and overlapped with Fe element by EDX mapping analysis, As(V) was adsorbed on FeOOH from aqueous phase. The breakthrough curves of the fixed bed adsorption were analyzed using the well-established column models which are Yoon-Nelson and Thomas models. The calculated results were well fitted with both models at high inlet concentrations and slow feed rate rather than that at low one and fast one. The maximum adsorption amount of As(V) on the FeOOH particles in the cryogels, which was obtained from the fixed bed adsorption at the inlet concentration of As(V), showed Langmuir type adsorption isotherm. The FeOOH particles prepared and the FeOOH particles entrapped in PAA cryogels were determined to be α-FeOOH by FT-IR spectrum. The XPS analysis of FeOOH-PAA cryogel after adsorption of As(V) detected As-3d peak and the shape change of O-1s peak.