Novel Cellulose-Based Hectocycle Nanopolymers for Arsenic Removal from Groundwater

Cellulose-based nano polymers with heterocyclic moieties were prepared by reacting cellulose with 2-amino pyridine (Cell-X), pyridine-2-carbonyl chloride (Cell-Y), or furan-2-carbonyl chloride (Cell-Z). The novel synthesized derivatives were characterized and evaluated as adsorbents for Arsenic removal from an aqueous solution. In order to maximize the adsorption efficiency of Arsenic, the optimum solution conditions of time, pH, temperature, adsorbent dosage, and Arsenic initial concentration were determined. The highest removal percentages of Arsenic from water were 91.65%, 96.73% and 95.54% for Cell-X, Cell-Y and Cell-Z, respectively. The best equilibrium isotherm of each process was investigated based on the experimental and calculated R2 values of Freundlich and Langmuir adsorption models. In addition, the adsorption kinetics were investigated using pseudo-first-order and pseudo-second-order adsorption kinetic models. Van’t Hoff plot was also determined for each process in order to detect the changes in adsorption enthalpy (∆H), Gibbs free energy (∆G) and Entropy (∆S). The obtained results showed that all adsorption processes fitted with both Freundlich and Langmuir adsorption isotherm, and all mechanisms followed pseudo second-order kinetic model. Negative values of the thermodynamic parameter ∆G° indicate spontaneous adsorption processes. The results indicate that the synthesized nano polymers could be promising absorbents on a commercial scale for Arsenic removal from water to a drinkable for safe consumption.