University of Kashan Journal of Nanostructures 2251-7871 14 3 2024 07 01 Preparation of Nano Lignin–Based Activated Carbon Depending on Ratio Impregnation of K2CO3, Activation Time and Activation Temperature on Yield for Congo Red Dye Adsorption 857 874 114565 10.22052/JNS.2024.03.016 EN Masar Mohammed Abd Alhussein Department of Chemistry, College of Education, University of Al-Qadisiyah, Diwaniyah, Iraq Nahla Shakir Salman Department of Chemistry, College of Education, University of Al-Qadisiyah, Diwaniyah, Iraq Journal Article 2024 04 05 This study involves the synthesis of nano form of activated carbon (AC) adsorbent derived from agricultural biomass (lignin) for effective removal of congo red (CR) dye from water. Chemical activation using potassium carbonate (K2CO3) was employed for transforming lignin into AC. The effects of impregnation ratio, activation time, and temperature on adsorbent’s properties were studied. Characterization techniques, including FTIR, XRD, SEM-EDX, BET-BJH, and TEM, highlighted the successful synthesis of activated carbon with a porous structure. Results revealed that the optimal AC, prepared with a K2CO3/lignin ratio of 2:1, demonstrated excellent adsorption capabilities for CR dye removal. Various parameters including contact time, adsorbent dose, pH, and temperature were evaluated to determine the optimal conditions for maximum dye removal efficiency. The results indicated a maximum removal efficiency of 89.93% under optimized conditions. Thermodynamic study revealed the endothermic and spontaneous nature of studied process. Isotherm models such as Langmuir, Freundlich, and Temkin models revealed that the Langmuir model best described the adsorption behaviour, suggesting a chemisorption mechanism. Additionally, the kinetic studies further supported the pseudo-second-order model, highlighting the chemical-controlled adsorption process. Overall, results showed the promising nature of synthesized adsorbent for CR dye removal.  https://jns.kashanu.ac.ir/article_114565_9ad7be76ed8426337ea50439182b736a.pdf