Investigations on the Biosorption of Nickel Using Tea Leaves and Tea Fibre (Camellia Sinensis) as Adsorbents: Thermodynamics, Isotherms and Kinetics

Abstract

Abstract The adsorption behavior of tea leaves and tea fibre (Camellia sinensis) as low-cost adsorbent with respect to nickel was investigated to justify its usage in waste water treatment. A good number of adsorption constrains were investigated which provides information about the effect of pH value, temperature, dose of the prepared adsorbent, time of contact as well as the starting concentration of the simulated system on the sorption process itself.From the result of these studies, these constrains aforementioned, shows increases steadily with increase in the parameters until desorption set in thereby influenced the adsorption process while temperature decreases with increase in temperature. The kinetics was best described by the pseudo second-order which gave the most convincing fit. The Langmuir isotherm give R2 values of 0.990 and 0.985 for tea leaves and tea fibre and Freundlich isotherm gives 0.985 and 0.980 values for tea leaves and tea fibre correspondingly with the Langmuir isotherm having higher R2 values considered the most suitable. In the long run, these process was considered to be endothermic, spontaneous and of cause thermodynamically feasible hence, the adsorbent was considered fit for waste water treatment.