Effective Removal of Molybdenum(VI) from Aqueous Solution Using Polyethylene Polyamine-Grafted Sugarcane Bagasse Biosorbent

A novel greenness and low-cost biosorbent was prepared by polyethylene polyamine-modified waste biomass of sugarcane bagasse in this study, which was used to remove molybdenum(VI) from aqueous solution. The structural properties and adsorption mechanism of this amine-functionalized sugarcane bagasse adsorbent (SCB-A) on Mo(VI) were investigated by SEM-EDS, BET, TG, FTIR, XPS, and batch adsorption experiments. The results show that the adsorption reaction between SCB-A and Mo(VI) was a spontaneous endothermic process, and its theoretical maximum adsorption capacity was about 231.48 mg/g. The adsorption capacity was 8.93-fold compared to that of pristine sugarcane bagasse. This adsorption process was more consistent with the Langmuir model and pseudo-second-order kinetics model, indicating that this process was monolayer adsorption on a homogeneous surface and the adsorption rate was controlled by the chemisorption process. SCB-A possessed great reusability, maintaining a stable adsorption capacity after five recycles. For the adsorption toward Mo(VI), SCB-A also exhibited superior selectivity in a multi-ion coexistence solution. Therefore, SCB-A has tremendous potential in the economically and feasible removal of Mo(VI) from wastewater.