Removal of malachite green from aqueous solution by metal-organic framework as an efficient sorbent

Adsorption is a simple, rapid and economical method for removal of organic pollutant such as cationic dyes (malachite green, MG) from aqueous solution and provision of clean water. The most important problem in adsorption process is finding the efficient adsorbent with high capacity and surface area. Among the recent adsorbent, Metal-organic frameworks (MOFs) show very high potential for removing the different water pollutants. MOFs are a class of porous hybrid inorganic-organic materials whose structure is made up of extended three-dimensional networks of inorganic metal centers connected via bridging organic linkers. An Erbium-organic framework was prepared by hydrothermal reaction under the optimum condition and characterized by powder X-ray diffraction (PXRD) and FT-IR spectroscopy and scanning electron microscopy (SEM). Also, the BET surface area of the activated Er-MOF is determined to 775 m2/g. For adsorption study, 1.8 mg MOF was added to 5ml of solution including MG and stirred. After centrifuging at 12000 rpm for 4 min, adsorption spectrum of MG was recorded by UV-Visible spectrophotometer. The adsorption capacity of MOF for MG was evaluated base on kinetic and isothermal adsorption experiments. The maximum adsorption capacity for MG was 294 mg/g. Results show the synthesized MOF can be used as a good alternative for the effective removal of organic dyes from environmental water and wastewater.