Characterization of Punica granatum L. peels and quantitatively determination of its biosorption behavior towards lead(II) ions and Acid Blue 40.

In this study, a waste biomass of Punica granatum L. (P. granatum L.) peels was firstly characterized by means of Brunauer-Emmett-Teller (BET) surface area, elemental analysis, FT-IR, thermogravimetric (TG) analysis and zeta potential measurement techniques. FT-IR results indicated that the mechanism involved in the biosorption of lead(II) ions and AB40 onto biosorbent was mainly attributed to lead(II) ions and dye binding of amino, carboxylic, hydroxyl and carbonyl groups. The biosorption abilities of P. granatum L. peels for lead(II) ions and Acid Blue 40 (AB40) were then investigated. Biosorption equilibrium and kinetic data fit well by the Langmuir isotherm and the pseudo-second-order kinetic models, respectively. The maximum biosorption capacities were 193.9 mg g(-1) for lead(II) ions and 138.1 mg g(-1) for AB40. Biosorption processes were spontaneous and endothermic in nature according to the thermodynamic results and the equilibrium was attained within 50 min. The validity of used kinetic models in this study can be quantitatively checked by using a normalized standard deviation Δq(%). Finally, the biosorption procedure was adopted to treat the real and simulated wastewaters including several metal salts and dyes. The wastewater applications have shown that the biosorbent indicated a reasonable biosorption capability to remove lead(II) ions (98.07%) and AB40 (94.76%) from industrial wastewaters.