Adsorption kinetics and mechanisms of nickel (II) ion sorption using carbonized unmodified sorghum (Sorghum bicolor) hull of two pore sizes (150μm and 250μm)

Imaga C. C, Abia A. A and Igwe

Abstract

Aim of this study was to investigate the use of unmodified and carbonized Sorghum Hull (CUSH 150μm and 250μm) in the removal of Nickel (II) ion from aqueous solution. The effect of contact time was investigated and reported. The maximum adsorption for 150μm and 250μm were at 40thand 60thminutes respectively (38.254mg/l and 38.545mg/l). Both pore sizes showed peak adsorption of Ni2+at different adsorption time respectively. Kinetic modelling of the results of Ni2+ of both pore sizes were also investigated. These results showed that Pseudo second order kinetic model best describes the process and the Mechanism of adsorption show that both 150μm and 250μm were film diffusion controlled. This will serve as parameters to consider in the design of treatment plants for heavy metal detoxification using biosorbents of different pore sizes.