Valorization of mollusk shell biowaste for efficient fluoride adsorption: insights from response surface methodology

In this research endeavor, response surface methodology (RSM) was employed to optimize the fluoride adsorption process using mollusk shell-derived adsorbents as a sustainable and cost-effective solution for water decontamination. A central composite design (CCD) comprising 18 experimental runs was implemented to assess the influence of three critical factors: initial fluoride concentration (5–12 mg/L), temperature (25–60 °C), and pH (4–9), with a fixed contact time of 25 min. The response variable was fluoride removal efficiency (%). The RSM model effectively identified optimal conditions for maximum fluoride removal. The highest removal efficiency of 93.16% was achieved at a temperature of 41 °C, pH 5, and an initial fluoride concentration of 10.5 mg/L. These findings highlight the potential of mollusk shells as an efficient biosorbent for fluoride removal from aqueous systems.