Adsorptive removal of crystal violet from aqueous solution by bioadsorbent

The present work investigates the efficiency of orange peel incorporated polyvinyl alcohol/carrageenan film in removing crystal violet from an aqueous solution. The composite was characterized spectroscopically and microscopically, along with mechanical and thermogravimetric analyses. The dye adsorption capacity of film was assessed by the batch adsorption method. The effect of operational parameters like initial concentration of CV, equilibrium time, adsorbent dosage, and temperature on removal efficiency is demonstrated. The adsorption mechanism responsible for the efficient elimination of CV dye from the aqueous stream is discussed using electrostatic aspects. The film showed excellent dye removal efficiency for CV (89%) at an adsorbent dosage of 0.05 g within 160 min at room temperature. The adsorption isotherm is described by the Langmuir and Freundlich models. Meanwhile, both pseudo-first and pseudo-second order models were found to be suitable to describe the adsorption process. The film showed excellent recyclability and maintained strong removal efficiency (82%) even after five adsorption–desorption cycles.