Raw pomegranate peel as promise efficient biosorbent for the removal of Basic Red 46 dye: equilibrium, kinetic, and thermodynamic studies

This work reports the use of raw pomegranate peel (RPP) as a low-cost biosorbent for the removal of Basic Red 46 (BR46) dye from aqueous solution. The XRD pattern indicates the amorphous nature of RPP. Hydroxyl (OH), carboxyl (COOH), and amine (NH2) are the main functional groups of the biosorbent. The scanning electron microscopy (SEM) shows the heterogeneous and rough surface of RPP. The Brunauer-Emmett-Teller (BET) surface of 1.046 m(2).g(-1) and the average pore diameter of 60.121 angstrom indicate that the molecule could easily access into the pores. The pH at the zero point charge (pH(pzc)) and the Boheme titration show the slight acidic property of RPP. Reduced particle size of RPP gives up an increase of the adsorption capacity of 70 mg.g(-1) in 2 min, to attain 86.13 mg.g(-1) with a removal rate of 86% in 60 min of contact for initial dye concentration of 200 mg.L-1 and biosorbent dosage of 2 g.L-1. Biosorption experimental isotherms data fit well with the Temkin model. The adsorption process of BR46 onto RPP was spontaneous, exothermic, and the pseudo-second order described was found to fit the kinetic data. The adsorption mechanism of BR46 onto RPP was proposed with the multiple reuse promising application in environmental wastewater recycling with RPP. [GRAPHICS] .

Automated summary

This study demonstrates the use of raw pomegranate peel as a low-cost biosorbent for efficient removal of BR46 dye from aqueous solution, showing promising adsorption capacity and potential application in environmental wastewater recycling.