Modeling and analysis of batch extraction process for efficient removal of cadmium and pathogens from aqueous solution using modified plantain peel biochar

Consumption of water contaminated with pathogens and heavy metals is responsible for the demise of millions of people around the globe. To find a low cost, facile and benign route for developing a biosorbent capable of handling the challenges associated with unsafe drinking water, the study report the preparation, activation, adsorption and removal of cadmium and pathogenic organisms from water samples. Modified plantain peel biochar (MPPB) was characterized using Braunauer-Emmett-Teller (BET) surface area and X-Ray diffraction (XRD). Surface area and pore size of the MPPB determined from BET surface area plot are 8.79 cc/g and 16.69 m2/g respectively with XRD crystallite size of 14.56 nm. The maximum adsorption capacity was observed to be 366.300 mmolkg-1. Equilibrium isotherm indicated the coefficient of determination to increase from Jovanovich →Elovic→Temkin→Freundlich→Langmuir model. Surface interaction and mass transfer kinetics shows a mixture of intra-particle diffusion and mass transfer process. The adsorption kinetics and surface interaction models coefficient of determination increased from Bangham pore diffusion →mass transfer model→Liquid film diffusion→pseudo first order→Dunwald-Wagner→Elovic→Pseudo-second order→Weber and Moris model. The adsorption indicated a chemisorption process with rate limitimg step likely to involve electron pair donor-acceptor interactions, hydrogen bonding and dipole dipole interactions. Antimicrobial evaluation of MPPB showed that it is a potential antimicrobial agent against common micro-organisms.