Adsorption of 2,4-dichlorophenoxyacetic acid and glyphosate from water by Fe3O4-UiO-66-NH2 obtained in a simple green way

Abstract

In this study, a green adsorbent (Fe3O4-UiO-66-NH2) with the ability of addressing the issues of separation and recovery of UiO-66-NH2 is obtained using a simple co-precipitation method under environmentally benign conditions. Various characterization techniques are utilized for evaluating the properties of the developed adsorbent. The capability of Fe3O4-UiO-66-NH2 towards 2,4-dichlorophenoxyacetic acid (2,4-D) and glyphosate (GP) from solution is explored. The results revealed that the magnetization process did not destroy the crystal structure of UiO-66-NH2, which ensured that Fe3O4-UiO-66-NH2 had good adsorption performance for 2,4-D and GP. The adsorption processes showed a wide pH application range, high salt tolerance, and regeneration performance as well as an excellent adsorption rate. Results from thermodynamic study showed that both processes were spontaneous and endothermic. The unit uptake ability of Fe3O4-UiO-66-NH2 for 2,4-D and GP reached up to 249mg·g-1 and 183mg·g-1 from Langmuir model at 303K, respectively. When solid-liquid ratio was 2g·L-1, Fe3O4-UiO-66-NH2 can reduce the content of 2,4-D or GP with the initial density of 100mg·L-1 below the drinking water requirement limit. In addition, the reusability efficiency of Fe3O4-UiO-66-NH2 towards 2,4-D and GP was found to be 86% and 80% using 5mmol·L-1 NaOH as eluent. Analysis of simulated water samples indicated that Fe3O4-UiO-66-NH2 could achieve the single or simultaneous removal of 2,4-D and GP from wastewater. Summarily, Fe3O4-UiO-66-NH2 as a green adsorbent can serve as an alternative for removing 2,4-D and GP from water body.