Isotherm and Kinetic investigations of toxic metal decontamination from biofluid by untreated biosorbent using a Batch design

The biosorption potential of biosorbent (Opuntia fragalis leaves) for decontamination of Zn (II) ions from Human blood plasma (biofluid) was investigated. The influence of biosorbent dose, concentration of Zn (II) ions, pH and rate of biosorption was examined at constant physiological temperature (۳۷۰C). FTIR results of the biosorbent revealed that –C-Br, -C-N, -N-O, -N-H, -C≡C- and –OH functional groups were responsible for the biosorption of Zn (II) ions from Human blood plasma. SEM micrograph revealed the active available pore sites responsible for the binding of Zn (II) ion unto Opuntia fragalis leaves. The optimum detoxification of Zn (II) ions was attained at biosorbent dose of ۱.۵ g, initial concentration of Zn (II) ion at ۴۰ mg/L, pH at ۶ and rate of biosorption of Zn (II) ions at ۷۰ min. The experimental data were subjected to four adsorption isotherm models; Langmuir, Freundlich, Temkin and Dubinin-Radushkevich Isotherms. The adsorption process fits into Temkin isotherm with correlation coefficient R۲ value of ۰.۹۳۷۶, the maximum monolayer coverage capacity, Qm is -۱.۲۵۲۲ mgg-۱, Langmuir isotherm constant KL is -۱.۰۲۹ Lmg-۱, separation factor RL is -۱.۰۲۹ revealed a favorable biosorption process. The biosorption experimental data was modelled with Pseudo-first order, Pseudo-second order, Elovich and Intra particle diffusion kinetic models. Pseudo first order model explained the biosorption process best with R۲ = ۰.۹۹۹۸. The interaction between Zn (II) ions and Opuntia fragalis leaves defined a chemisorption reaction which involved chemical bonds formation

Keywords:

Biosorption Batch studies , Kinetics , Isotherm , Opuntia fragalis