Fabrication of lanthanum-based phosphate binder using cross-linked alginate as a carrier

Abstract

In this paper, phosphate binding properties of lanthanum carbonate loaded sodium alginate cross-linked beads (LaC@SA) were investigated. The beads were shaped when the alginate solution (with La₂(CO₃)₃ dispersed in it) was dropped in calcium ion solution. During this process, the alginate macromolecular chains combined with each other. The morphology of the LaC@SA beads was observed using scanning electron microscopy. Thermal gravimetric analysis and X-ray diffraction analysis were also applied to confirm the existence of the LaC solid in the beads. The LaC@SA beads showed good swelling abilities in different aqueous circumstances. The phosphate binding behavior was investigated through the molybdenum blue spectrophotometric method. The beads exhibited maximum phosphate binding capacity at pH 5 and 45 °C, but at the same time, the capacity showed no remarkable differences from 25 to 65 °C or pH from 1 to 7. Thus, the LaC@SA beads may have potential applications in environmental management, wastewater treatment and moreover, treatment of hyperphosphatemia patients.