A Mannich base biosorbent derived from alkaline lignin for lead removal from aqueous solution

A Mannich base biosorbent (AML) was prepared by grafting alkaline lignin (AL) with methylamine and formaldehyde. The effects of dosages, reaction time, pH and temperature of reaction on the nitrogen content of AML were investigated. A maximum nitrogen content of the Mannich base could reach to 8.32%. It was characterized by scanning electron microscopy (SEM), element analysis, and gel permeation chromatography (GPC). Kinetic adsorption suggested AML possessed fast adsorption for Pb2+ and followed a second-order model. Adsorption equilibrium results indicated AML had a maximum uptake of 60.5 mg/g for Pb2+ which was 4.2-fold higher than AL. The AML has good potential for cleanup of wastewater.

Figure optionsDownload as PowerPoint slide