Activation of iron based persulfate heterogeneous nano catalyst using plant extract for removal of tetrabromobisphenol A from soil

Contamination of tetrabromobisphenol A (TBBPA) in soils posed a high risk to human health and ecological systems. Iron based heterogeneous catalytic persulfate (PS) advanced oxidation technology has significant advantages in the degradation of TBBPA. However, how to effectively prepare iron-based materials for large-scale soil remediation was still controversial. Hence, the study aimed to determine whether plant extracts can effectively replace traditional chemical reagents to prepare iron nanoparticles (Fe NPs) for soil TBBPA degradation. In this study, Fe NPs synthesized from leaf extracts of Tung tree (T-Fe NPs), Aspen (A-Fe NPs), and Holly (H-Fe NPs), were applied in the activation of persulfate (PS) to remove TBBPA from soils. The main active substances in plant leaf extracts were 8 flavonoids, 6 polyphenolics, 4 polysaccharides, and 2 proteins, among which phenols played a crucial role in the formation of Fe NPs. The characterization by SEM, XRD, FTIR and XPS showed that the formed Fe NPs were amorphous structures with irregular spherical shape and mainly existed in the form of iron oxides and hydroxides. These three kinds of Fe NPs can effectively activate PS to degrade soil TBBPA, wherein, PS activation by T-Fe NPs showed the highest removal efficiency (82.07%), the fastest reaction rate (0.14 h−1), and the least affection on environmental factors. In conclusion, T-Fe NPs can effectively degrade TBBPA and have high application potential.