Aquatic pollution, which includes organic debris and heavy metals, is a severe issue for living things. Copper pollution is hazardous to people, and there is a need to develop effective methods for eliminating it from the environment. To address this issue, a novel adsorbent composed of frankincense-modified multi-walled carbon nanotubes (Fr-MMWCNTs) and Fe3O4[Fr-MWCNT-Fe3O4] was created and subjected to characterization. Batch adsorption tests showed that Fr-MWCNT-Fe3O4had a maximum adsorption capacity of 250 mg/g at 308 K and could efficiently remove Cu2+ions over a pH range of 6 to 8. The adsorption process followed the pseudo-second-order and Langmuir models, and its thermodynamics were identified as endothermic. Functional groups on the surface of modified MWCNTs improved their adsorption capacity, and a rise in temperature increased the adsorption efficiency. These results highlight the Fr-MWCNT-Fe3O4composites’ potential as an efficient adsorbent for removing Cu2+ions from untreated natural water sources.