Mechanism of adsorption of Cu2+ and Zn2+ on the corn silk (Zea mays L.)

•Raw corn silk as novel adsorbent for copper and zinc has been investigated.•Adsorption process of metal is favorable and occurs under monolayer surface.•The involvement of complexation and ion – exchange binding mechanisms is confirmed.•Adsorption process is feasible, spontaneous and endothermic.•Adsorbent can be efficiently regenerated and reused.