The co-existence ofdifferent pollutants is considered to be one of the most dangerous sources of environmental pollution, and multicomponentremoval studies are useful to identify the competitiveperformance of several pollutants and play an important role forthe proper design and operation ofwater purification processes.

In this work, The competitive removal of Pb2+ and malachite green (MG) from water by three magnetic phosphatenanocomposites (Fe3O4/Ba3(PO4)2, Fe3O4/Sr5(PO4)3(OH), and Fe3O4/Sr5xBa3x(PO4)3(OH), namely “FBP”,“FSP”, and “FSBP”, respectively) was systematically investigated compared with Fe3O4 (“F”) nanoparticle.In the competitive removal process, FSP showed a high affinityto Pb2+ (202.8 mg/g) while FBP possessed high selectivity for MG (175.4mg/g), and FSBP waseffective at simultaneous removal of Pb2+ and MG, with a capacity of 143.7 and 90.9 mg/g, respectively.The magnetic contents in nanocomposites allow magnetic separation of materials from the water aftertreatment. We proposed that the simultaneous removal mechanism by FSBP was due to ion exchangebetween Pb2+ and Sr2+ in the lattice and then the formation of hydrogen bonds between PO43-outsidethe material's surface and positively charged hydrogen in MG. This study indicates the potential of thesephosphate nanocomposites to be used as effective materials for selective or simultaneous removal ofPb2+ and MG from water.

Link:

http://www.sciencedirect.com/science/article/pii/S0043135418309862