Enhanced copper adsorption by DTPA-chitosan/alginate composite beads: Mechanism and application in simulated electroplating wastewater

•A novel DTPA-chitosan/alginate composite adsorbent (Ca-DTCS/ALG beads) was prepared.•Ca-DTCS/ALG showed high copper removal efficiency in strongly acidic solutions.•Na+, Ca2+ and Al3+ had little effect on copper removal efficiency by Ca-DTCS/ALG.•Ca-DTCS/ALG could recover copper from simulated electroplating wastewater high efficiently.•DTPA modified chitosan (DTCS) reached copper adsorption equilibrium within 1 min.