Highly Efficient Lead(II) Sequestration Using Size-Controllable Polydopamine Microspheres with Superior Application Capability and Rapid Capture

In this work, we successfully prepared the mussel-inspired polydopamine microspheres (PDA-Ms) with controllable sizes, through a facile self-oxidative polymerization method. The prepared PDA-M biomaterial with environmentally benign properties exhibits efficient lead(II) sequestration against high salts of competitive Ca(II), Mg(II), or Na(I) ions. It reveals 30 times greater than the commercial ion-exchanger 001x7 by selectivity evaluation. Kinetic results show that an exceedingly rapid lead(II) uptake can be achieved below 1 min. More attractively, the prepared PDA-Ms further exhibit the distinguished application ability with superior treated capacity of ∼42000 kg contaminated water/kg sorbent, and the effluents can be reduced from 1000 μg/L to below 10 μg/L, reaching the drinking water standard (WHO), which is equal to 200 times greater than commercial ion exchanger resin (∼210 kg) and granular activated carbon (∼120 kg). In addition, the exhaust PDA-M material can be well regenerated and repeated use ...