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Hydrogen peroxide (H2O2)-based advanced oxidation technology has emerged as a cost-effective and green solution for tackling soil pollution. Given the highly heterogeneous nature of soil, the effectiveness of H2O2remediation is significantly influenced by its diffusion distance in soils. However, the dynamics of H2O2diffusion and its effective range remain largely unexplored, primarily due to the lack of analytical methods for mapping H2O2in soils. This study introduces a precipitation-based fluorescent probe (PFP) method for in situ, high-resolution (micrometer scale) mapping of H2O2diffusion in soils. Using the PFP method, we visualized real-time H2O2diffusion in various types of soils, revealing distinct diffusion patterns with rates ranging from 0.011 to >0.56 mm min–1. The observed differences in diffusion rates are associated with soil permeability. Additionally, soils exhibited a wide range of diffusion distances, from 0.22 to >11 mm in 20 min. Soil’s reactivity for H2O2decomposition, a previously overlooked factor, is critical in determining the diffusion distance of H2O2. We further demonstrate that the efficacy of H2O2diffusion in soils is a pivotal factor in controlling pollutant degradation and soil remediation efficiency. These findings enhance our understanding of reagent diffusion processes in soil remediation, informing the optimization of more efficient soil remediation strategies.

Burn is a suddenly occurring injury. The healing process of burn is complex. Aloe vera(L.) Burm.f. (Av) is widely used as Chinese folk medicine for the treatment of burn. While effective pharmacological components, role and mechanism of Av in the treatment of burn remain to be fully elucidated. Arachidonic Acid (AA) and Quercetin (QUE) are identified as active components of Av for the treatment of burn by network pharmacology analysis and experimental verification. Animal experiments’ results showed that AA and QUE could shorten the burn wound healing time. The expression of inflammatory factor TNF-α, MyD88 and P-NF-κB p65 were down-regulated and the ER (ESR1), SRC were up-regulated in AA treated NIH 3T3 cells. The expression of MyD88 was downregulated in QUE treated NIH 3T3 cells. The Av promotes burn healing may be via the anti-inflammatory effect and regulation on NF-κB signal pathway or estrogen signal pathway by its active components AA and QUE. This research may construct a bridge between Av and burn wounds, and skin therapy agent exploration.

Indirect photolysis driven by photochemically produced reactive intermediates (PPRIs) is pivotal for the transformations and fates of pollutants in nature. While well-studied in bulk water, indirect photolysis processes at environmental interfaces remain largely unexplored. This study reveals a significant acceleration of indirect photodegradation of organic pollutants at the soil–water interface of wetlands. Organic pollutants experienced ubiquitously enhanced indirect photodegradation at the soil–water interfaces, with rates 1.41 ± 0.01 to 4.27 ± 0.03-fold higher than those in bulk water. This enhancement was observed across various natural and artificial wetlands, including coastal wetlands and rice paddies. In situmapping indicated that soil–water interfaces act as hotspots, concentrating both organic pollutants and PPRIs by 9.30- and 4.27-folds, respectively. This synchronized colocation is the primary cause of the accelerated pollutant photolysis. Additionally, the contribution of each PPRI species to pollutant photolysis and a coupled transformation pathway at the soil–water interface significantly differed from those in bulk water. For instance, the contribution of singlet oxygen to metoxuron photolysis increased from 10.1% in bulk water to 44.4% at the soil–water interface. Our study highlights the rapid indirect photolysis of organic pollutants at the soil–water interfaces, offering new insights into the natural purification processes in wetlands as “Earth’s kidneys.”

Electron release and transfer are pivotal to the efficiency of multiple biogeochemical and pollutant processes. Despite substantial efforts to develop electron-transfer characterization techniques, in situvisualization of electron transfer remains challenging. This study introduces an innovative strategy for mapping electron-transfer distance using nanoscale zerovalent iron (nZVI) as a case study. In this method, silver ions (Ag+) are employed as electron traps, forming silver nanoparticles. These nanoparticles can then be immobilized in the agarose-solidified gel used as a heterogeneous porous medium to simulate the underground aquifer and visualized through photothermal imaging. In situdetection has unveiled remarkably extensive electron transfer, reaching distances of up to centimeters from the nZVI source. Nationwide groundwater investigations have further confirmed this long electron-transfer distance, ranging from 1.7 ± 0.4 to 9.6 ± 0.1 mm (agarose gel may not fully replicate the complex and heterogeneous conditions of groundwater environments). Importantly, the efficiency of electron transfer from nZVI was primarily influenced by factors such as nZVI dosage and groundwater matrix conditions, particularly the abundance of electron-shuttling materials like natural organic matter. Surprisingly, the inherent properties of nZVI had a lesser impact on electron-transfer distance. Our work highlights the long-distance electron transfer from nZVI, revealing a previously overlooked but ubiquitous nZVI remediation process.