Construction Of Mussel Inspired Polydopamine Platform And Deep Purification Of Heavy Metals

Heavy metal pollution in waters is a world-wide issue and development of advanced technology for enhanced heavy metal removal is an important research areas.In this dissertation,we successfully prepared the mussel-inspired polydopamine microspheres(PDA-MS),through a facile self-oxidative polymerization method.The size can be well controlled using different alkaline additions.The obtained PDA-Ms 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 001 × 7 by selectivity evaluation.The lead(II)uptake is a solution pH dependent process with optimal pH =4.0-6.5.Kinetic results show that an exceedingly rapid lead(II)uptake can be achieved in below 1 min.More attractively,the prepared PDA-MS further exhibits the distinguished application ability with superior treated capacity of ? 42000 Kg contaminated water / Kgsorbent,and the effluents can be reduced from 1000?g/L to below 10 ?g/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,theexhaust PDA-MS material can be well regenerated and repeated use using binary 1% HCl+5% Ca(NO3)2 solution.Similar to the lead(II)uptake,the PDA-MS also exhibits efficient Cr(VI)removal performances.The mechanism can be ascribed to the well-dispersed nanoscale morphology as well as the strong amine and carbonyl/hydroxyl group for complexation formation.Furthermore,polydopamine is also used as an efficient biological coating,which can coat on nearly all the material surface at alkaline surroundings,which provides the effective inorganic-organic compatibility.Herein,inspiring by the strong adhesion of polydopamine,a new composite(D001-PDA-PEI)was prepared by introducing PDA onto the surface of anionic exchange resin D001 and then for PEI modification.It reveals outstanding sorption selectivity,fast kinirics(50 min)and efficient regeneration performances(five cycles).Column tests display that the D001-PDA-PEI can effectively reduce Pb(II)to below 10 ?g/L,with available capacity of 1750 BV,which reaches the drinking water standards recommended by WHO.