Removal of Copper (II) from Aqueous Solution by a Hierarchical Porous Hydroxylapatite-Biochar Composite Prepared with Sugarcane Top Internode Biotemplate

Porous hydroxyapatite-biochar composites with layered microstructures (SC–HA/C) were prepared by carbonizing sugarcane stem nodes and then soaking them in lime water (NH4)2HPO4 solutions rotation. The surface area of SC–HA/C ranges from 8.52 to 28.44 m2/g, its microstructure inherits various macro-, meso-, micro-pores the cell walls pits vessel walls. maximum removal capacities 11.50, 14.65, 19.81 mg/g for Cu (II) immobilization at 25 °C, 35 45 °C solution concentration 10~320 mg/L, respectively, which accordance copper sorption synthesized nano-hydroxylapatites. (II)-removal kinetics isotherm followed pseudo-second-order equation Langmuir very well. formation Cu-containing hydroxylapatite solid ((CuxCa1?x)5(PO4)3(OH)) through adsorption, ion exchange (x = 0.01~0.04), dissolution-coprecipitation 0.13~0.35) was dominant process composite.