Title
Doehlert experimental design and density functional theory for the removal of Bezathren blue dye from aqueous solution
Authors
AFAF AMARA-REKKAB and SARAH BOUHASSOUN

Received July 26, 2024
Published Volume 59 Issue 1-2 January-February
Keywords dyes, wastewater, removal, optimization, Doehlert design, DFT, environment

Abstract
Bezathren blue (BB) is a commonly used dye in the textile industry and it is difficult to remove during wastewater treatment. In this study, chitosan was used as an adsorbent and the process of liquid-solid extraction was employed to remove BB from an aqueous solution. The process parameters were optimized individually, using the Doehlert experimental design (DED). The DED predicts that the output will reach a maximum of 99.98% when slightly modified process conditions are used. This entails placing a mass of 0.095 g of chitosan in contact with the BB solution, which has a starting concentration of 45 ppm. The solution had an initial pH of 6.5, which is its normal pH, and this pH was maintained for 17.5 minutes. A study was conducted on the Mulliken atomic charges, focusing on the electronic properties using the density functional theory (DFT) technique. FMO (HOMO–LUMO), MEP, and ESP were all looked at as part of the study.