Improvement strategies on metal–organic frameworks (IFMC-1) as adsorbent and its kinetic study for dye pollutant removal and wastewater treatment

Abstract

Green application of a high-nitrogen, zeolite-like, porous metal–organic framework, IFMC-1 (Institute of Functional Material Chemistry), is reported for dye pollutant removal and wastewater treatment. The IFMC-1 contained a high-nitrogen-content ligand without an NH2 group (H3dttz), dimethylacetamide, and Zn ion. The synthesis of H3dttz from diaminomaleonitrile was initiated after closure of the triazole ring and formation of 4,5-dicyano-2H-1,2,3-triazole as an intermediate material; thus, two tetrazole rings were obtained in a 1,3-dipolar cycloadditionn. Only four nitrogens of the IFMC-1 ligand coordinate with zinc, and 63.6% of the nitrogens are free. The IFMC-1-based tetrazole without an NH2 group was investigated for removal of methylene blue (MB) and basic red 46 (BR-46) pollutants. The results indicated that the IFMC-1 adsorbent effectively removed the MB and BR-46 dyes from solution. The contaminant adsorption capacity of IFMC-1 for MB and BR-46 was 293.9 and 135.2 mg g–1, respectively. Investigation of isotherm and kinetic data of dye removal using the synthesized absorbent indicated that it follows the Langmuir isotherm and pseudo-second-order kinetics.