Application of novel magnetic lignin hydrogels: Activated persulfate degrades pesticide contaminants.

Lignin hydrogels have garnered significant attention due to their distinctive three-dimensional structures and potent swelling ability. In this work, a novel magnetic nanocomposite lignin hydrogel (MNLH) was fabricated through organic synthesis and solution immersion reduction. The obtained MNLH was used to activate persulfate(PDS) for pesticide degradation. Scanning electron microscopy (SEM), X-ray diffractometry (XRD), Brunauer-Emmett-Teller (BET), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FTIR) were used to characterize the structure and morphology of MNLH. The influence of factors such as the lignin hydrogel to nano-zero-valent iron (nZVI) and copper oxide (CuO) mass ratio, MNLH dosage, initial pH on the MNLH/PDS/imidacloprid (IMI) system. Remarkably, the MNLH/PDS/IMI system has a removal rate of up to 100%. Quenching and electron paramagnetic resonance (EPR) studies disclosed that the MNLH/PDS system degraded IMI through a combination of free radical and non-free radical pathways, with the latter being dominant. More importantly, in this study, the toxicity and hydrolysis sites of IMI were analyzed using ECOSAR and Gaussian09, respectively, confirming the feasibility of activating persulfate with MNLH. These findings underscore the potential of MNLH as a function material suitable for facilitating the persulfate-activated degradation of organic pollutants.