Modification of zirconia for enhancement of photocatalytic on heavy metal removal / Nabilah Yasmin Shamsol Afandi and Norain Isa

This study covers the fabrication of zirconia nanotubes modification with other material to remove heavy metal from wastewater. Zirconia has been widely studied due to its various application, chemical and physical properties. As heavy metals are known to have harmful effects to human, animal and environment, therefore, it is important to remove or reduced the concentration of the compound. In this study, comparative study was made based on the synthesis of zirconia nanotubes and removal of heavy metal in wastewater. Experimental work on zirconia nanotubes is doped with iron (II) sulphate heptahydrate by anodization method. This method involves the immersing of electrode in electrolyte of constant voltage. Two method of anodization were used for synthesis of ZrO2 nanotubes. Power of 60 V was supply for the anodization process to take place with air bubbler to mix the electrolyte. The characterizations and morphologies of the nanotubes were carried out using SEM and EDX. A ring structure on the surface of the foil confirms the formation of nanotubes for 0.5 M concentration of iron solution. As for the removal of heavy metals, it was made by comparative study. Based on previous studies, the use of freestanding zirconia nanotubes gives high degradation of heavy metal however it decreased as the pH increase. A high removal of heavy metal also can be achieved in doping than undoped ZrO2. The adsorption of As(III) on undoped and doped ZrO2 carbon nanowires were 2.58 mg/g and 28.61 mg/g while for As(V) 3.65 mg/g and 106.57 mg/g, respectively. Therefore, doping of zirconia with iron compound may give high rate of removal of heavy metal, thus reduced the pollution of heavy metal in water.