The present invention discloses the Synthesis and application of MOFs/natural polymers composite beads adsorbents. To overcome the drawback of MOFs, in an embodiment, both novel MOFs/sodium alginate (MOFs/SA) and MOFs/chitosan (MOFs/CS) composite beads were prepared and characterized. Each composite beads include one or more of MIL-101 (Cr), MIL-100 (Cr), MIL-53 (Al), MIL-100 (Al), NH2-MIL-101 (Al), UIO-66, ZIF-8, ZIF-68, ZIF-67, and ZIF-9-67 nanoparticles. Adsorption of anionic contaminants onto the two composite beads was investigated and compared with pristine sodium alginate beads (SA) and chitosan beads (CS). The novel MOFs/SA beads all exhibit much higher adsorption capacity than SA beads; the novel MOFs/CS beads all exhibit much higher adsorption capacity than CS beads, which indicates that MOFs played a key role in the adsorption of anionic contaminants. The porous composite beads disclosed herein and related methods and devices may be used in adsorption technologies.