Synthesis and application of MOFs/natural polymers composite beads adsorbents

A method for preparing MOFs/natural polymers composite beads, wherein the beads comprises natural polymers as matrix and MOFs within the matrix, and wherein the natural polymers are chitosan, comprising of the steps of:

• (1) preparing MOFs nano-powders by the sub-steps of:
• blending metallic salt compounds, organic ligands compounds, and solvent;
• sonicating the blended mixture, placing the mixture in a Teflon-lined autoclave bomb, and keeping the mixture in an oven at 25-220° C. for 3-96 hours without stirring to synthesize crude MOFs;
• and
• separating synthesized crude MOFs solids from water using a centrifuge (8000 rpm, 10 minutes), washing the solids with methanol or ethanol, separating the methanol or ethanol from the solids by centrifugation, placing the solids in ethanol or DMF, sonicating the the solids for 10 minutes, keeping the solids at 70° C.;
• separating the resulting solids by centrifugation, repeatedly washing with ethanol or DMF, and drying the solids under vacuum at 80-140° C. for 2 days to form the MOFs nano-powders;
• (2) adding the MOFs nano-powders from step (1) and natural polymers were-added to a water or acetic acid solution and mixing together to obtain a homogeneous MOFs-natural polymers solution;
• (3) preparing either a CaCl2-ethanol-H2O solution at pH=1-4 or a Na5P3O10-ethanol-H2O solution;
• (4) dropping the homogeneous MOFs-natural polymers solution from step (2) to the solution from step (3) to obtain the MOFs/natural polymers composite beads;
• and
• (5) suspending the MOFs/natural polymers composite beads suspended in a cross-linking reaction medium containing glutaraldehyde at pH=0.5-2 and 10-40° C. for 6-24 hours, or at pH=4-7 and 25-50° C. for 6-24 hours.