Fast separation of cadmium and lead ions from contaminated water using conjugates of magnetic nanoparticle-DTPA

Novel magnetic sorbent-conjugates of surface functionalized magnetic nanoparticle-chelator-has been developed for separation of heavy metal ions from aqueous systems, which offers a simple, fast, effective and environmentally benign technique in wastewater treatment compared to traditional methods. In this paper, we have coupled diethylene triamine pentaacetic acid (DTPA) to double coated magnetic nanoparticles (dMNPs). The results confirmed that it is an excellent sorbent for cadmium and lead sorption, which can be easily manipulated and separated from aqueous solution by applying a small external magnetic field. The metal sorption was fast, reaching the equilibrium in 30 min and strictly conforming to the pseudo-second-order-reaction mechanism. The sorption capacity calculated by Langmuir model was 8.06 mg/g for Cd and 12.09 mg/g for Pb. The suitable pH range for Cd adsorption was pH 2-7, which was wider than that for Pb which was pH 3-6.