Marine alga Bifurcaria bifurcata: biosorption of Reactive Blue 19 and methylene blue from aqueous solutions

In this study, we have investigated the removal efficiency of two organic pollutants: methylene blue (MB) and Reactive Blue 19 (RB19) dyes by using a brown marine alga abundantly available on the Moroccan coastlines called Bifurcaria bifurcata (Bif-Bcata). During the experiments that were conducted in batch mode, we have studied the effect of some parameters such as pH, Bif-Bcata mass, contact time, and initial dye concentration in order to optimize the most suitable biosorption conditions. The biosorption tests on Bif-Bcata showed that the equilibrium is reached after 15 min for both dyes MB and RB19. The optimal pH values are 5.6 and 1.0 for MB and RB19, respectively. Kinetic studies revealed that the biosorption of both dyes follows the pseudo-second-order model. The biosorption isotherms demonstrated that the Langmuir model is the most appropriate to describe the biosorption equilibrium for both dyes MB and RB19 with maximum biosorption capacities reaching 2744.5 mg/g for MB and 88.7 mg/g for RB19. According to these results, it is clear that Bif-Bcata can be considered a promising biomaterial to be used as an effective biosorbent for the elimination of cationic and anionic dyes from textile effluents.