Biocomposite based on N-maleated chitosan immobilized in amino-carbamated alginate matrix for effective biosorption of Cu(II)

Abstract

Abstract Synthesis of a biocomposite based on N-maleated chitosan immobilized in amino-carbamated alginate matrix (NMC-PSC) was carried out. Facile chemical modifications of sodium alginate and chitosan were executed using maleic anhydride and 4-phenylsemicarbazide as chemical modifiers, respectively. NMC-PSC hydrogel beads were employed for Cu(II) biosorption from aqueous media. Study of surface characterization, morphology and chemical structure of the sorbent indicated the successful surface functionalization and attachment of Cu(II) ions. Sorption parameters like pH, time of contact, sorbent dosage and adsorbate content significantly influenced the sorption capacity. Kinetic results demonstrated that copper sorption on NMC-PSC was governed by chemisorption and ion-exchange rather than merely mass transfer. Equilibrium sorption data closely fitted with Langmuir model and maximum Langmuir monolayer binding capacity (q m ) was determined as 207 mg/g. The negative ΔG o values indicated the spontaneity of Cu(II) sorption process while ΔH o and ΔS o parameters indicated the exothermic nature of sorption which proceeds with rise in entropy.