Abstract This study examines the biosorption of Methylene Blue (MB), Basic Blue 41 (BB41), Reactive Red 120 (RR120), Methyl Red (MR), and Trypan Blue (TB) dyes, commonly used in the textile industry, using Juniperus drupacea cone as an biosorbent. The effects of biosorption time, initial dye concentration, temperature, pH, and particle size on dye removal efficiency were investigated. Characterization techniques such as SEM-EDX, FTIR, isotherm, kinetic, thermodynamic, and intraparticle diffusion analyses were performed. The Langmuir isotherm model indicated monolayer biosorption for MB and BB41, whereas the Freundlich isotherm suggested heterogeneous biosorption for RR120 and MR. The biosorption process followed the pseudo-second-order kinetic model, highlighting the dominance of chemical interactions. Thermodynamic analysis confirmed that MB and BB41 biosorption was spontaneous, while MB biosorption was exothermic. Intraparticle diffusion analysis suggested that biosorption was not solely controlled by intraparticle diffusion but also influenced by surface biosorption. The highest removal efficiency was recorded as 97.77% for MB under optimal conditions (pH 10, 55 °C, 75 μm biosorbent size). BB41 exhibited a maximum removal efficiency of 92.63%, with increasing biosorption at higher temperatures. The results demonstrate that Juniperus drupacea cone is an efficient and environmentally sustainable biosorbent for dye removal from wastewater. The study contributes to sustainable wastewater treatment technologies and offers a promising alternative for valorizing underutilized plant materials. These findings support the use of low-cost biosorbents in environmental applications and provide a foundation for future research on industrial-scale implementation.
Argun et al. (Fri,) studied this question.