Cellulose with urethan crosslinks decorated with ionic functionality for wastewater purification including design, synthesis, and theoretical studies

Numerous water treatment techniques and a wide range of organic, inorganic, hybrid, and/or composite materials have been developed in response to the demand for clean water. In this work, we report a novel cellulose-based urethane with ionic functionality in foam form as a useful adsorbent for the removal of contaminants, particularly metal ions from wastewater. The foam preparation involved carboxymethylation of cellulose taken from the solid waste of the olive industry, copolymerizing the carboxymethylated cellulose with p-phenylene diisocyanate and hexamethylene diisocyanate to produce carboxymethyl cellulose phenylene diisocyanate polyurethane foam (CMC-PPUF) and carboxymethyl cellulose hexamethylene polyurethane foam (CMC-HMPUF), respectively. Lead (II) was used as a model ion to assess the adsorption effectiveness of both foams and to determine ideal adsorption conditions. Both foams demonstrated the capacity to quantitatively eliminate uranium and over 20 other metal ions found in a swage sample. The maximum qe value was determined to be 29.1 and 33.2 mg/g for CMC-HMPUF and CMC-PPUF respectively, in a spontaneous adsorption process as shown by obtained values of the thermodynamic parameters. The kinetic and isothermal studies showed that a Langmuir isotherm model and the second-order adsorption rate are followed in the adsorption process. Monte Carlo (MC), Density functional Theory (DFT), and Dynamic (MD) simulations showed strong bonding between lead(II) ions and coordination sites of both foams. Since high adsorption negative energy was obtained. The prepared foams proved to be a valuable adsorbent for use in a commercial filtering plant.