Adsorption removal of cationic dyes from wastewater using the corn straw modified with diethylenetriaminepentacetic acid ligand

• Published in: Journal of Chromatography A Vol. 1720; p. 464781
• Main Authors: Hu, Hongbin, Zhao, Lang, Yao, Lu, He, Min, Lv, Yuwei, Li, Rong
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 12.04.2024
• Subjects: Adsorption; Adsorption behavior; Cationic dye; Cations; Coloring Agents - chemistry; Corn straw; Density functional theory; Diethylenetriaminepentacetic acid; Gentian Violet - chemistry; Kinetics; Ligands; Methylene Blue - chemistry; Pentetic Acid; Wastewater; Water Pollutants, Chemical - chemistry; Zea mays; Corn straw; Density functional theory; Cationic dye; Adsorption behavior; Diethylenetriaminepentacetic acid
• ISSN: 0021-9673; 1873-3778
• DOI: 10.1016/j.chroma.2024.464781

•A novel synthesis approach was proposed for preparing DTPA modified CS.•Modified CS material was applied to remove cationic dyes for the first time.•The electrostatic adsorption mode of the modified CS for cationic dyes was proved. Taking the thiazide cationic dye methylene blue (MB), triphenylmethane cationic dye crystal violet (CV), monoazo cationic dye cationic red 46 (R-46), and polycarboxycyanine cationic dye cationic rosé FG (P-FG) as the research objects, the adsorption behaviors of a self-made corn straw modified adsorbent HQ-DTPA-I for the dyes were investigated in depth. Under optimized conditions, HQ-DTPA-I can quickly adsorb most dyes within 3 min and reach equilibrium adsorption in 15–20 min. The removal rates of HQ-DTPA-I to MB, CV, R-46 and AP-FG can reach 95.28 %, 99.78 %, 99.28 % and 98.53 %, respectively. It also has good anti-interference ability for common ions present in most actual dye wastewater. For six consecutive adsorption-desorption cycles, the adsorption performance of HQ-DTPA-I can still reach 80.17 %, 81.61 %, 90.77 % and 83.48 % of the initial adsorption capacity, indicating good recovery performance. Based on Gaussian density functional theory to calculate its surface potential energy, it is found that the adsorption mechanism of HQ-DTPA-I for the cationic dyes is mainly due to the electrostatic interaction between the carboxyl groups in ligand DTPA and amino groups in dye molecules.