removal of textile dyes on a biosorbent based on the leaves of atriplex halimus

The objective of this study is to characterize the biosorbent (atriplex halimus leaves) and its application in the removal by adsorption of anionic and cationic dyes known for their toxicity such as bemacid blue (bb), bemacid red (br), and methylene blue (mb) contained in water. the atriplex halimus was characterized by boehm's method, ft-ir, xps, sem, ph zero charge point (phzpc), iodine value, and methylene blue value. the tests carried out in this experiment showed that the biosorbent can remove bemacid blue (bb), bemacid red (br), and methylene blue (mb). the effect of several parameters such as ph of the solution, biomass dose, contact time, initial concentration of dye used, and the temperature was studied in a batch system. the adsorbate adsorbent equilibrium times are reached after 60 min for mb and 90 min for bb and br. the adsorption is maximal for an adsorbent dose of 8 g/l for the three dyes. the best retentions were observed at ph 11, 6.45, and 5.12 for mb, bb, and br respectively. the maximum adsorption capacities are 289.8, 29.7, and 32.9 gm/l for methylene blue (mb), bemacid blue (bb), and bemacid red (br) respectively. modeling of the experimental data showed that the langmuir and pseudo-second-order models describe, respectively, the adsorption isotherms and the kinetics in a satisfactory way. the study of the thermodynamic aspects showed that the adsorption of the three dyes by the leaf biomass of atriplex halimus is a favorable, exothermic, and spontaneous phenomenon.