Competitive adsorption of Cu(II) and Cd(II) ions by chitosan crosslinked with epichlorohydrin-triphosphate

► Adsorption of Cu(II) and Cd(II) ions in single and binary metal systems. ► The metal ion adsorption process is dependent on the solution pH. ► The Langmuir model provided the best fit for the experimental adsorption data. ► The order of the affinity of adsorbent for the metal ions was: Cu(II) ≫ Cd(II). ► The adsorbent could be regenerated and reused for the adsorption of metals.