Hybrid Methods Combining Computational and Experimental Measurements for the Uptake of Eriochrome Black T Dye Utilising Fish Scales.

The current work describes the removal efficiency of a hazardous azo dye such as Eriochrome Black T from aqueous solution using Sardina fish scales as an inexpensive biosorbent which the characterisation results indicate the presence of hydroxyapatite and collagen fibres. Various parameters that can influence the uptake, like contact time, pH, biosorbent dose were investigated, and the optimal experimental removal efficiency was found at acidic pH. The adsorption behaviour of EBT dye on both collagen and hydroxyapatite (HDA) was highlighted using Metropolis Monte Carlo (MC), radial distribution function (RDF), the density functional theory (DFT), and the electrostatic potential surface (ESP) calculations. The findings result in evidence that the EBT dye presents more capabilityto be adsorbed on the collagen than on the HDA surface mainly in an acidic medium. A good agreement between experimental and theoretical conclusions is obtained. The results illustrated that the experimental data were well followed by the pseudo-second-order kinetic and Freundlich isotherm models. Thermodynamic parameters were determined and show that the biosorption of dye was endothermic. [ABSTRACT FROM AUTHOR]