Chemical Engineering / Kimya Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/14
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Article Citation - WoS: 13Citation - Scopus: 11Valorization of Olive Tree Pruning Waste for Potential Utilization in Lithium Recovery From Aqueous Solutions(Springer, 2022) Nampeera, Jackline; Recepoğlu, Yaşar Kemal; Yüksel, AslıOlive tree pruning waste, mainly composed of olive branches, was converted into a value-added and sustainable product capable of lithium as a biosorbent through alkali treatment and phosphorylation reaction. Characterization studies were performed by SEM–EDX, XPS, FTIR, and TGA. Factors affecting biosorption mechanism, i.e., sorbent dosage, pH, initial Li+ concentration and temperature, and competitive ions’ presence, were investigated the synthesized functionalized olive branches (FOB). A commercial lithium selective resin, Lewatit TP 260, was also compared with FOB in batch and column studies. The Freundlich model fits adsorption isotherms better than the Langmuir model, with a maximum adsorption capacity of 6.7 mg/g at 30 °C and pH 7–8. Kinetic studies proved fast kinetics and equilibrium were attained in 6 min, while thermodynamic studies showed an exothermic (Δ Ho= - 17.52 kJ/ mol) , spontaneous reaction Δ Go< 0 at all temperatures), and increased randomness Δ So= + 24.27 J/ mol. K) at the interaction interface. Column studies revealed that although Lewatit TP 260 resin showed higher sorption capacity, its desorption efficiency (50.42%) was lower than that of FOB (99.9%), and the degree of column utilization of FOB (56.81%) was better than Lewatit TP 260 resin’s (16.0%). The findings were encouraging in the successful synthesis of a promising biosorbent from an abundant waste in Turkey for use in sustainable lithium recovery from aqueous sources. Graphical abstract: [Figure not available: see fulltext.]Article Citation - WoS: 25Citation - Scopus: 26Phosphorylated Hazelnut Shell Waste for Sustainable Lithium Recovery Application as Biosorbent(Springer, 2021) Recepoğlu, Yaşar Kemal; Yüksel, AslıHazelnut shell waste was phosphorylated to develop a novel biosorbent based on natural renewable resource for the recovery of lithium from aqueous solution. For the synthesized biosorbent, the surface morphology and mapping by SEM-EDS, chemical properties by FTIR, elemental analysis by XPS, specific surface area by BET, crystallinity by XRD and thermal properties by TGA were elucidated elaborately. The influence of biosorbent dosage, initial concentration, temperature, contact time, pH and coexisting ions were investigated. The equilibrium sorption capacity reached 6.03 mg/g under optimal conditions (i.e., biosorbent dosage of 12.0 g/L, initial Li concentration of 100 mg/L, pH value of 5.8, sorption temperature of 25 degrees C, and sorption time of 6 min). According to the sorption behavior of the phosphorylated hazelnut shell waste the Freundlich model proved to be more suitable than the Langmuir model indicating maximum sorption capacity as 7.71 mg/g at 25 degrees C. Thermodynamic parameters obtained by different isokinetic temperatures disclosed that the ion exchange reaction was feasible, spontaneous, and exothermic where the interaction between biosorbent surface and solvent plays an important role. A preliminary test on the Li recovery from geothermal water was also performed to check its applicability in a real brine. Desorption studies at 25 degrees C revealed that relatively higher desorption efficiency and capacity were achieved at 97.4% and 5.93 mg/g, respectively with a 1.0 M H2SO4 among other regenerants (i.e., HCl and NaCl). Concentrations of Li and the other cations were determined via ICP-OES. Due to such outstanding features, the novel phosphorylated hazelnut shell waste had great potential for lithium recovery from aqueous solution by being added value as a waste and recovering a strategic element of modern life simultaneously. [GRAPHICS] .