Fabrication and charaterization of PAN/Zn-MOF fibrous composites fordye removal

The existence of dyes as contaminants in wastewater sources from the textile industry can leadto serious health problems if not treated properly. Furthermore, the release of dye effluents intothe aqueous environment can pose serious problems for human health and the environment [۱-۳].Herein, the separation of dyes over two isoreticular nanoporous Zn(II)-MOFs known as TMU-۱۷and TMU-۱۷-NH۲ owing to the effect of amine groups on the adsorption capacity wasinvestigated, which can effectively and selectively adsorb Methyl Orange (MO) and Congo Red(CR) as anionic dyes. In addition, polyacrylonitrile (PAN) polymer was used to fabricate metalorganicframework (MOF) nanofibrous mat as a membrane to remove organic pollutants. To verifythe structures, the samples were investigated by FTIR, XRD, SEM, and TGA measurements.Liquid phase adsorption experiments were performed to determine the maximum adsorptioncapacity. Varied conditions such as initial dye concentration, contact time, pH, and temperaturewere assessed. The Langmuir and Freundlich adsorption models were utilized to explain theequilibrium isotherm and isotherm constant computation. Three kinetic models such as pseudofirst-order, pseudo-second-order, and intra-particle diffusion equations were employed toinvestigate the adsorption performance. The adsorption results completely fitted the pseudosecond-order kinetic model. Additionally, CR and MO adsorption isotherms have fitted with theLangmuir model. Maximum equilibrium adsorption capacities of ۱۴۳.۲۷ and ۸۷۷.۱۹ mg g-۱ forMO and CR were determined. High selective adsorption for MO and CR over other dyes is alsorepresented. Over ۹۰% of adsorption ability was preserved after five adsorption-desorption cycles.This work shows that the samples could be used as efficient adsorbents for removal of pollutantsdyes from wastewater.

Keywords:

Metal-Organic Framework , Electrospun membranes , Adsorption , Separation