SYNTHESIS AND CHARACTERIZATION OF COPPER BASED METALORGANIC FRAMEWORKS FOR REMOVAL OF ORGANIC POLLUTANT.

Abstract The presence of dyes in wastewater can cause severe problems to human beings and aquatic life, and that warrants removal from aqueous media. Amongs the multiple strategies to treate dyecontaminated water, adsorption is considered superior because of flexibility, ease of operation and lower energy consumption. Metal organic framework (MOF) materials that are based on copper-3, 5-dinitrobenzoic acid were prepared by solvothermal method and then characterized by XRD, FT-IR, and Iodine Number. Cu-DNBA was applied to the adsorption of methylene blue (MB) from aqueous solutions were carried out to determine the effect of the adsorbent dose, contact time, pH, and initial MB concentration on the ability to reach equilibrium for methylene blue absorbed by copper-3, 5-dinitrobenzoic acid. The optimum contact time was obtained at 90 min, pH = 6, while the optimum adsorbent dosage was obtained at 0.2 g . The adsorption isotherms and kinetics were determined from the experimental data, and the results displayed that the Freundlich adsorption isotherm and pseudo second order kinetic model matched well for the adsorption of MB on to Cu-DNBA. The correlation coefficient (R2 ) for the Pseudo first Order (0.7688) model deviated more from the unity value compared to the Pseudo Second Order (PSO) (0.995). Freundlich istherm model fit in terms of R2 value. The better fitting of the PSO model confirmed that the adsorption was physicochemical in nature, while PFO showed a lower value. The data results displayed for the correction coefficient of Langmuir and Freundlich isotherms were (R2 = 0.62301) and (R2 = 0.9833) respectively. The closeness of the R2 value for the model indicated that the linear Freundlich isotherm model fits well for the adsorption of methylene blue on Cu-DNBA. Freundlich Linear model, constant n value for Cu-DNBA Was found to be more than one (i.e, n>1), these value confirm the favorability of MB adsorption on to single –metal and bi-metal Cu-MOF. This study can suggest the single Cu-DNBA as an attractive adsorbent to remove dyes from wastewater. The MOFs used in this study were suggested to be active adsorbents to remove dye from waste water. Further research has to be carried out on the removal capacity of this adsorbent for other organic dyes not only from the textile industry but also from leather industries and soap industries.