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.

Research progress of persulfate activation technology.

Persulfate-based advanced oxidation processes (PS-AOPs) have been widely investigated by academia and industry due to their high efficiency and selectivity for the removal of trace organic pollutants from complex water substrates. PS-AOPs have been extensively studied for the degradation of pesticides, drugs, halogen compounds, dyes, and other pollutants. Utilizing bibliometric statistics, this review presents a comprehensive overview of persulfate-based advanced oxidation technology research over the past decade. The number of published articles about persulfate activation has steadily increased during this time, reflecting extensive international collaboration. Furthermore, this review introduces the most widely employed strategies for persulfate activation reported in the past 10 years, including carbon material activation, photocatalysis, transition metal activation, electrochemical activation, ultrasonic activation, thermal activation, and alkali activation. Next, the potential activation mechanisms and influencing factors, such as persulfate dosage during activation, are discussed. Finally, the application of PS-AOPs in wastewater treatment and in situ groundwater treatment is examined. This review summarizes the previously reported experiences of persulfate-based advanced oxidation technology and presents the current application status of PS-AOPs in organic pollution removal, with the aim of avoiding misunderstandings and providing a solid foundation for future research on the removal of organic pollutants.

Adsorption behaviour of tetrabromobisphenol A on sediments in Weihe River Basin in Northwest China.

Tetrabromobisphenol A (TBBPA) is adsorbed on sediments in river environments, and various environmental factors have distinct effects on its adsorption behaviour. Investigating the adsorption behaviour of TBBPA on the sediments in Weihe River Basin is critical for protecting the water environment and providing a theoretical basis for the prevention and control of brominated flame retardant pollution. In this study, the adsorption behaviour of TBBPA on Weihe River sediment was investigated by conducting batch equilibrium experiments, and the effects of pH, dissolved organic matter, and ionic strength on the adsorption of TBBPA were discussed. The obtained results revealed that rapid adsorption was the main mechanism of the TBBPA kinetic adsorption process. The isothermal adsorption behaviour of TBBPA was well fitted by Freundlich model (R2 99.21%) than Langmuir model (R2 98.59%). The adsorption capacity for TBBPA is 34.13 mg/kg. The thermodynamic results revealed that the adsorption process of TBBPA by the sediment was a spontaneous endothermic reaction. The increase in pH and ionic strength inhibited the adsorption of sediments on TBBPA. With the increase in the humic acid concentration, the adsorption of TBBPA initially increased and subsequently decreased. Synchrotron radiation-Fourier transform infrared spectroscopy indicated that the adsorption mechanism of TBBPA on the surface of sediment was mainly π-π and hydrogen bonds. The obtained results are useful for understanding of TBBPA migration and transformation in river water bodies.