Montmorillonite-reduced graphene oxide composite aerogel (M−rGO): A green adsorbent for the dynamic removal of cadmium and methylene blue from wastewater

•M−rGO was synthesized in a green and low-cost method.•M−rGO had strong mechanical strength and good reusability.•The removal of Cd and MB onto M−rGO involved chemisorption and physisorption.•The effects of concentration, pH, IS, flow rate and coexistence on dynamic adsorption were investigated.•The adsorption of MB by M−rGO was promoted due to the presence of Cd.