Equilibrium and kinetics of sorption and resorption of acid and basic dyes using the pulp of carob pods

• Published in: Journal of dispersion science and technology Vol. 44; no. 11; pp. 2137 - 2149
• Main Authors: Seghier, Abdelkarim, Boucherdoud, Ahmed, Seghier, Soraya, Benderdouche, Noureddine, Hadjel, Mohammed, Bestani, Benaouda
• Format: Journal Article
• Language: English
• Published: Philadelphia Taylor & Francis 01-09-2023; Taylor & Francis Ltd
• Subjects: Aqueous solutions; Basic dyes; Biosorption; Carob pods; congo red; Dyes; Functional groups; Kinetics; Methylene blue; pulp of carob pods; solid reuse
• ISSN: 0193-2691; 1532-2351
• DOI: 10.1080/01932691.2022.2063882

Being an abundant product in Algeria, pulp of carob pods (PCP) was used in this study as a biosorbent for Methylene blue (MB) and Congo red (CR) removal from aqueous media in batch mode in two successive steps. Once the first dye is adsorbed, the biosorbent is used as is to adsorb the second dye in order to study the interactions between them. Characterization of PCP by FTIR spectroscopy, Scanning Electron Microscopy (SEM), EDX, and point of zero charge showed that the principal functional groups present at the surface are oxygenated with a pH
pzc
value of the 7.2. Contact time of 60 min was amply sufficient to reach equilibrium for both dyes onto PCP and recuperated biosorbents. pH effect on the biosorption onto PCP shows a behavioral divergence between both dyes. Maximum biosorption uptake of CR was observed at pH value of 6.38 while pH variation has no remarkable influence on MB biosorption and the initial pH solution of 5.75 was taken for subsequent biosorption experiments. The adsorption isotherms obtained are in good agreement with the models of Langmuir and Freundlich and the kinetics are well described by the pseudo-second-order model.