Abstract Turkish coffee is a widely consumed coffee type, generating large amounts of waste daily. Recycling coffee waste plays a crucial role in mitigating potential environmental risks. In this regard, we propose a study to explore the reuse of Turkish coffee waste (TCW) by incorporating it into a chitosan solution to create novel chitosan/TCW biocomposite beads. The prepared chitosan/TCW biocomposite was characterized through FTIR, BET surface area, SEM, and pH pzc analyses. The impact of various parameters, such as initial pH, contact time, Sr(II) concentration, and temperature, on Sr(II) sorption was examined using a 4-factor, 5-level Central Composite Design (CCD). The analysis of variance (ANOVA) results showed that the Model F -value of 97.32 indicates the model's significance. The coefficient of determination ( R 2 ) between the experimental and predicted results was 0.989. The adsorption data were best described by the D–R isotherm, which exhibited the highest determination coefficient ( R 2 = 0.999) and the lowest prediction errors, indicating superior agreement with experimental values. The biocomposite's maximum adsorption capacity was determined to be 17.20 mg g –1 . The kinetics of Sr(II) adsorption are well described by the pseudo-second-order kinetic model. Adsorption process is spontaneous, exothermic, and becomes slightly more favorable with increasing temperature. Competitive ion studies further revealed that the presence of competing cations significantly reduced Sr(II) uptake. Overall, the results demonstrated that the chitosan/TCW biocomposite can be effectively used for removing strontium from a wide range of aqueous solutions.
Baysal et al. (2026) studied this question.