Investigation of Mechanism and Critical Parameters for Removal of Arsenic from Water using Zr-TiO2 Composite

Abstract

Using microwave-hydrothermal method for synthesis of composite, high surface density of hydroxyl groups, as an active adsorption sites for arsenic, was obtained. Adsorption mechanisms of As(III) and As(V) onto zirconium doped titanium-dioxide (Zr-TiO2) was investigated and proposed using macroscopic and microscopic methods. Obtained results are suggesting innersphere and outer-sphere adsorption mechanisms for As(III) and As(V), respectively. This allowed us identification of parameters that are critical for the successful removal of arsenic from water, essential information for further optimization of the removal process. Composite was further applied for the removal of As(III) and As(V) from water in a dynamic flow through reactor. Column study proved that removal of both arsenic species below value recommended by WHO can be achieved. Elution of As(III) and As(V) from the composite can be done by using small amount of 0.01 M NaOH solution resulting in preconcentration of arsenic species and possible multiple usage of composite.