Removal of cadmium using ferro magnetic gels

Abstract

The removal of cadmium (Cd) from aqueous solution of cadmium chloride using ferromagnetic photocatalyst gel was investigated. The experiments were performed under sunlight and also away from sunlight. Recycling experiments were also performed to determine the durability of the ferromagnetic photocatalyst gel. The results revealed that removal of cadmium was higher in the presence of sunlight irradiation compared to without sunlight. Apparently the treatment process for Cd involved both adsorption and photocatalytic process. The removal rate of Cd was faster when it was exposed to sunlight where almost 100% of Cd was removed within 4 hours. The presence of pores was observed from FESEM images and such morphology was considered helpful for mass transfer of Cd(II) to the photocatalyst active sites embedded in the PVA-alginate magnetic beads. The PVA-alginate magnetic beads produced were reused after treating with 25 ppm of Cd(II) solutions without washing them. The performance of each cycle was about the same as the previous cycle until it reached the seventh cycle where the ferro photo gels start to lose its removal efficiency.