Synthetic strong base anion exchange resins: synthesis and sorption of Mo(VI) and V(V)

The result of synthesizing anion exchangers bearing trimethylammonium functionalities is presented. Ion exchange resins of poly(4-vinylbenzyltrimethylammonium chloride) (PVBTAC) (Resin 1) and poly(3-acrylamidopropyltrimethylammonium chloride) (PAPTAC) (Resin 2) were obtained via the radical polymerization technique and studies on the sorption of molybdenum and vanadium ions were conducted at 20, 30, and 40 °C using the batch method from single-component aqueous solutions. The greatest total sorption capacities were 198 mg Mo(VI) g⁻¹ at 20 °C and 193 mg V(V) g⁻¹ at 40 °C for Resin 1. The calculated thermodynamic parameters demonstrated that the sorption of Mo(VI) was an exothermic process, while the uptake of V(V) was endothermic. The kinetic studies revealed the compliance of the process with a quasi-second-order kinetic model. Simultaneously, equilibrium was achieved within 15 min in two rate-controlled stages. The fitting of the Langmuir and Freundlich mathematical models demonstrated the chemical character of the sorption processes. Elution and reuse studies showed that Mo(VI) may be completely recovered from both resins using a sodium carbonate solution. Moreover, the investigated materials are suitable for repeated sorption/desorption cycles.