Preparation of Chelating Flocculant Grafted with Diethylene Triamine and Its Performance for the Removal of Lead

Based on the Mannich-Reaction, a new kind of chelating flocculant grafted with diethylene triamine has been prepared from polyacrylamide (PAM), formaldehyde and diethylene triamine (DETA). Using the prepared flocculant to remove Pb²⁺ from waste water was studied. Due to the introduction of chelated functional group grafted on the long chain of PAM, the as-obtained flocculant has possessed the multiple merits, such as the properties of capturing Pb2+ and flocculation. Hereby, the flocculant should be very suitable for the flocculation, sedimentation, and removal of lead from waste water containing low concentration of lead. Thus, the optimal conditions for synthesizing the flocculant and using it to remove Pb²⁺ were investigated further. The results show that the synthetic process of the flocculant is easy to operate, and its performance of removing lead is fine. For the waste water of 50mg/L lead concentration, 90.0% of lead has been removed from water by adding the flocculant volumetric concentration of 0.02%. In brief, a novel and low-cost method to remove the lead from waste water is obtained.