MnO₂@Al‐BDC nanocomposite as adsorbent of remarkable high efficiency toward iron remediation from wastewaters

Abstract

Global environmental problems, especially those related to water contamination brought on by rapid industrialization and economic growth, are among the most dangerous threats facing humanity today. In this research work, Al3+ based metal–organic framework with 1,4‐benzenedicarboxylic acid (H2BDC) linker has been synthesized by a simple and economic coprecipitation method. The obtained Al‐BDC MOF was utilized as an adsorbent for sequestering iron from wastewater, but only 54.0% of iron concentration was eliminated after 120 min. To boost the removal efficiency, modification of the Al‐BDC MOF was carried out. MnO2@Al‐BDC nanocomposite was prepared and applied as a nanoadsorbent for iron remediation from water. The adsorption capability of Al‐BDC MOF was greatly enhanced by facile modification. The adsorption efficiency reached 97.0% using 35.0 mg of the nanocomposite after 120 min compared to 54.0% iron removal using the un‐modified MOF. The effect of pH of the medium was then studied using MnO2@Al‐BDC nanocomposite. The best elimination efficacy of iron was accomplished at pH ~ 2.2. The adsorption of iron on the surface of MnO2@Al‐BDC nanocomposite attains 97.0% (120 min) using a 35.0 mg dose of adsorbent and reaches 98.7% utilizing a 50.0 mg dose of adsorbent. In contrast, at pH = 9.2, the removal efficiency drops to 90.0% (after 120 min, 35.0 mg adsorbent). The adsorption capability was examined also using a variety of iron concentrations, i.e., 2.5, 5.0, and 7.5 mg/L where the adsorption efficiency dropped notably upon increasing the concentration. It dropped from 96.3% to 87.0% using 35.0 mg of MnO2@Al‐BDC nanocomposite at 90 min. The newly developed adsorbent showed a pronounced efficiency for Fe3+ removal against real samples collected from different water sources. Ultimately, this research introduces a novel MnO2@Al‐BDC nanocomposite, synthesized through a simple and economical coprecipitation method, to address water contamination by iron. The innovation lies in the significant enhancement of iron elimination efficiency, from 54.0% with unmodified Al‐BDC MOF to 97.0% with the MnO2@Al‐BDC nanocomposite.