Using an external field facilitates the generation of smaller and more uniform particles through the electrospray process. In the current research, calcium alginate biopolymers were produced as a biosorbent by combining ionotropic gelation and electrospray techniques, utilizing voltage levels from 0 to 6 kV. Alginate hydrogels were produced under different operating conditions, with sizes ranging from 1.15 to 2.31 mm, and applied to remove the methylene blue dye from synthetic wastewater. The maximum efficiency of dye removal in biosorbents produced with different sizes was investigated in acidic, neutral, and alkaline pH values. Based on the results, the particles produced with a voltage of 6 kV, a nozzle diameter of 1 mm, and a flow rate of 100 mL/min, with an average diameter of 1.15 mm, have more efficiency in fast dye removal from an aqueous solution. The maximum efficiency of dye removal from the solution containing 30 ppm of methylene blue, obtained under optimal operating conditions of the device and at pH = 12, was achieved at 91.6%. The thermodynamic studies (ΔG° = -9870 J.mol-1, ΔH° = +13282.4 J. mol-1, and ΔS° = +72.81 J.mol-1.K-1 at 318 K) showed that alginate beads were both an endothermic and spontaneous process. This research demonstrated that integrating the ionotropic gelation technique with the electrospray method can enhance the pollutant removal efficiency by significantly decreasing the particle size.
