Poly(Acrylic Acid) Grafted Sodium Alginate Di-Block Hydrogels as Efficient Biosorbents; Structure-Property Relevance

Naturally-based poly(acrylic acid) grafted sodium alginate di-block hydrogels were investigated as high efficiency biosorbents for copper(II) ion. The grafted di-block hydrogel was characterized using FTIR, TGA and SEM techniques. Blank and immobilized algal biosorbent beads formed via 2.0% (w/w) calcium ions were also investigated. Batch adsorption experiments revealed optimal pH dependence of copper(II) ion biosorption at pH 5.5 with high efficient copper(II) ion uptake of 98.5 mg/g. The dynamics studies showed that the high efficiency copper(II) ion biosorption followed pseudo-second order kinetics with significant contribution of intraparticle diffusion mechanism. The equilibrium data fitted to Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) adsorption isotherm models. Thermodynamics parameters for copper(II) biosorption on blank and immobilized algal beads depicted the spontaneous nature of the biosorption process. Such high efficiency, feasibility, simplicity, and low cost properties adapt the di-block biosorbent to be the next generation promising biosorbents for water decontamination and to help in the recovery of the missing ecologic harmony.