Fabrication of cellulose-collagen based biosorbent as eco-friendly scavengers for uranyl ions

The aim of the present research is to fabricate a biosorbent using agricultural waste for removal of uranium from contaminated water i.e. "waste to wealth" approach. Cellulose extracted from wheat straw was mercerized and a novel semi-interpenetrating polymer network (semi-IPN) was fabricated through graft copolymerization of polyvinyl alcohol onto hybrid mercerized cellulose + collagen backbone. Response surface methodology was used for optimization of different reaction parameters as a function of % grafting (195.1 %) was carried out. Semi-IPN was found to possess higher thermal stability. Adsorption results revealed that the optimum parameters for the elimination of uranium using semi-IPN were: adsorbent dose = 0.15 g, pH = 6.0, contact time = 120 min and initial U (VI) concentration = 100 μg/L. The pseudo-second-order kinetic model gave the best description of the adsorption equilibrium data as the calculated q_e value is nearest to the experimental q_e for the different initial U(VI) concentrations. Adsorption experiments followed Langmuir isotherm with R² = 0.999. Furthermore, recyclability and reusability studies showed that the adsorption efficiency of semi-IPN was 82 % after 5 cycles indicating the superior recycling execution of fabricated biosorbent. Thus, the fabricated ecofriendly device can be used effectively for the removal of uranium from contaminated wastewater sources.