Simultaneous adsorption of methyl orange and methylene blue from aqueous solution using amino functionalized Zr-based MOFs

Nowadays efficient and rapid removal of organic dyes from wastewater is still a complicated task with great challenge. Herein, the amino groups functionalized UiO-66 (denoted as UiO-66-NH2) was synthesized via a one-step process and then applied in simultaneous removal of methyl orange (MO) and methylene blue (MB) for the first time. The as-prepared UiO-66-NH2 showed excellent adsorption ability to both MO and MB, and the maximum adsorption capacities were as high as 148.4 (MO: pH = 5, T = 25 degrees C) and 549.6 (MB: pH = 9, T = 25 degrees C) mg/g, respectively. Significantly, UiO-66-NH2 exhibited highly pH-dependent selective adsorption for MO and MB. More interestingly, the simultaneous removal of MO and MB from the MO/MB mixture solution could be achieved by UiO-66-NH2 under neutral condition. The adsorption mechanisms and reusability were also investigated. Overall, UiO-66-NH2 could be a perfect candidate for removing MO and MB application in dye containing wastewater treatment. And the results from this study also provided some new insights for the treatment of wastewater containing various dyes.