Adsorption Kinetics And Mechanism Of Pb(Ii), Cd(Ii) And Ni(Ii) Ion Sorption From Aqueous Medium Using Activated Calopo (Calopogonus Mucunoides) Seed Pod:- Aleruchi Christian C.

ABSTRACT

In this research calopo seed pod an agricultural product, available in large quantity in south region of Nigeria, were used as low-cost adsorbent for removal of metal ions such as Pb(Il), Cd(ll) and Ni(ll). Batch operation was used to study the equilibrium behavior of calopo seed pod. The effects of solution pH, and contact time of adsorbent for Pb(II), Cd(II) and Ni(II) ions were evaluated. To study the kinetics of adsorption of Pb(ll), Cd(ll) and Ni(ll) onto calopo seed pod, pseudo-first-order, pseudo-second-order and intra-particle diffusion( Weber and Morris, Mickey and Poot) model, Mass transfer Model, and liquid film Models were used. Adsorption process undergoes pseudo-second-order kinetic as proved by the high value of R2 (Pb(II) 52.63mg/g >, Cd(II) 50.00mg/g > Ni(II) 47.67mg/g) and mechanism of adsorption show that the process was intraparticle controlled - Weber and Morris Model with R2 values of Cd(II) 0.891mg/g > Pb(II) 0.761mg/g > Ni(II) 0.750mg/g. In addition, the results indicates that calopo seed pods are very effective adsorbent for the removal of for Pb(ll). Cd(Jl) and Ni(II) ions from aqueous medium. This will serve as a parameter to consider in the design for waste water treatment plant for heavy metal detoxification using calopo seed pod.