Adsorption of Cu (II) from water by an innovative graphene oxide-carboxymethyl cellulose-acrylamide composite: characterisation, performance, and mechanism

The development of adsorbents to remove heavy metal ions from water with high adsorption capacity and recyclable performances has always been the focus and challenge of current research. A new type of high-efficiency heavy-metal adsorbent, (graphene oxide/carboxymethyl cellulose)-acrylamide (GO/CMC-AM) was prepared in this paper. The adsorbent was prepared through graft copolymerisation by aqueous solution polymerisation. The results showed that CMC, AM, and GO are successfully grafted to form a three-dimensional network structure. The adsorption kinetic followed the pseudo-second-order kinetic model, and the isotherm adsorption curve was highly consistent with the Langmuir model. The theoretical maximum adsorption capacity of (GO/CMC)-AM for Cu (II) reached 289.7 mg/g. After 5 adsorption cycles, the removal rate of Cu (II) still remains as high as 75.1%. Overall, (GO/CMC)-AM exhibits rapid, efficient, and stable adsorption performance, highlighting its broad application potential in treating heavy-metal wastewater.