Adsorption behavior and mechanism of modified Fe-based metal–organic framework for different kinds of arsenic pollutants
Mengwei Gao, Bing Li, Jue Liu, Yuanan Hu, Hefa Cheng
Abstract
Arsenic in water environment can present significant threats to human health, and eliminating arsenic pollutants from wastewater is crucial. Based on our previously reported work, this study delved into the adsorption behavior and mechanism of different arsenic contaminants (p-ASA, ROX, As(V), and DMA) on the activated Fe-based metal-organic framework (activated MIL-88A). The results show that activated MIL-88A exhibits exceptional adsorption capabilities toward diverse arsenic pollutants. The adsorption process is endothermic, spontaneous, and viable, and chemical adsorption plays a leading role. The remarkable adsorption capacity of activated MIL-88A to various arsenic pollutants is primarily attributed to coordination, while hydrogen bonding also assumes a significant role in the elimination of p-ASA and ROX. Additionally, we investigated the impact of arsenic molecule shape and size, solution pH, and the existence of specific anions and dissolved organic matter (DOM) on the adsorption of different arsenic pollutants. This study can provide valuable insights for further exploring the selective adsorption of different kinds of arsenic species by Fe-based MOF materials and improving the adsorption efficiency of MOFs.