Green Synthesis of Biochar Derived from Nutshell Biomass as a Highly Adsorbent Surface for Removal of Brilliant Blue Dye: Experimental and Molecular Dynamics Simulation

Abstract

The modification of carbon from Nut shell was done via carbonization at 500 °C and activated under acidic conditions with H3PO4. Thus, Nutshell (NS) and chemically activated carbon utilizing acid H3PO4, the biochar surface will be referred to as NS-H3P will exhibit comparable capacity in removing BB dye compared to commercial activated carbon (CAC). The NS-H3P adsorbent has been characterized by field emission scanning electron microscope (FESEM), energy-dispersive X-ray spectroscopy (EDX), and transmission electron microscope (TEM). Effect of several factors like equilibrium time (5-60 min), the weight of adsorbent (0.01-0.08 g), the concentration of dye (10 -50 mg/L), pH solution (2.8-10.3), and solution of temperature (10-45 oC) were investigated. The equilibrium result tends to fit best with isotherm Freundlich than isotherm Langmuir. The isotherm Freundlich model with a high R2 was utilized to describe multi-layer adsorption. Desorption of dye studies was performed with NaOH, HCl, and H2O. Computational modeling was performed to obtain deeper mechanistic insights on the adsorption behavior of the BB dye molecules onto (002) sheet of Biochar. This modeling section includes Monte Carlo space exploration for the lowest adsorption energy configurations of the BB dye molecule on the Biochar surface. The process included an adsorption locator calculations module.