Biosorption potential of Sargassum muticum algal biomass for methylene blue and lead removal from aqueous medium

In this examination, the proficiency of alga biomass Sargassum muticum for simultaneous uptake of methylene blue (MB) and lead (II) (Pb 2+ ) ions from aqueous solution is investigated. The brown alga is surveyed by scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR) and nitrogen adsorption–desorption procedures. Impact of operating variables (brown alga mass, contact time and initial MB and Pb +2 -ion concentration) on the simultaneous contaminants uptake is performed by means of central composite design and upgraded through response surface method (RSM). Accuracy of the equation procured by RSM is checked by the variance investigation and computing of determination coefficient ( R 2 ) among predicted and the experimental values of simultaneous noxious substances removal. Bon accord among empirical and envisaged values is commented. The optimum conditions are settled at contact time (30 min), 39 mg L −1 for MB and 30 mg L −1 for Pb 2+ ions and brown alga mass (0.3 g) to reach maximum retention percentage. Adsorption kinetic depicted three phases intra-particle diffusion mode and coordinated the pseudo-second-order design very well. Batch equilibrium results reveal that MB and Pb 2+ ions biosorption onto alga biomass could be all around portrayed by Langmuir isotherm model contrasted with Freundlich approach. In any case, removal percentage elaborated from column studies is inferior to those computed from batch technique. Column can be recouped and reutilized even after 5-adsorption–desorption cycles. X-ray photoelectron spectroscopy and FTIR scrutinies uncovered that hydroxyl, carbonyl and amino functional groups are responsible for the biosorption of both pollutants onto non-living brown alga. Previous tests achieved on paint wastewater demonstrated that the invasive biomass Sargassum muticum could be an effective and promising biosorbent for dye/metal wastewater treatment. Graphic abstract