Removal of phosphorus from water using scallop shell synthesized ceramic biomaterials

This study describes the development of scallop shell synthesized ceramic biomaterial for phosphorus removal from water. The synthesized biomaterial was characterized by scanning electron microscope, Brunauer–Emmett–Teller and X-ray diffractometer methods. The influences of contact time, initial phosphate concentration, initial solution pH, co-existing ions and temperature for phosphorus removal were investigated by batch experiments. The results indicated that the equilibrium data can be fitted by the Langmuir isotherm model at temperatures ranging from 15 to 55 °C, with the maximum sorption capacity of 13.6 mg/g. Sorption kinetics followed a pseudo-second-order kinetic equation model. The sorption process was optimal at a wide range of solution pH (above 2.4), with a relatively high sorption capacity level. Phosphorus sorption was slightly impeded by the presence of F⁻, HCO₃ ⁻ and NH₄ ⁺ ions, and significantly inhibited by Cl⁻, SO₄ ²⁻ and NO₃ ⁻ ions. Sorption process appeared to be controlled by a chemical precipitation processes. The mechanism may be attributed to ion complexation during subsequent sorption of phosphorus on scallop shell synthesized ceramic biomaterial.