A large amount of oily soil (OS) is inevitably generated in the oil exploration and development process, which leads to serious environmental issues . However, the purification of OS remained a great challenge due to the unclear mechanism. In this work, the desorption behavior of OS with different particle sizes was investigated by microemulsion (ME) elution based on the accumulation effect and binding interaction. The oil removal efficiency ( R e ) of OS has been studied in four elution systems. The result confirmed that LAS-M can better remove oil contaminants. In addition, the accumulation effect, the distribution coefficient ( K D ) varied with the solid concentration ( C p ), was elaborated using the SCA-Langmuir model in detail. The results indicated that small particle-size OS has a more significant accumulation effect, which facilitated the desorption of oil molecules. Furthermore, XRD and XRF were employed to detect the soil mineral composition. The FT-IR and zeta potential analysis revealed that the rich feldspar mineral in larger particle-size soil enhanced oil-soil binding interaction, directly leading to a decreased oil desorption capability. Finally, accumulation effect and binding effect revealed that small particle OS (∼41 µm, 89.17%) had higher R e than large particle OS (∼643 µm, 74.23%). The study provided a theoretical basis for the remediation of industrially contaminated soil.
Graphene quantum dots (GQDs) are well-known for its potential applications for bioimaging , biosensor, and drug carrier in biomedicine . GQDs are well characteristic of intrinsic peroxidase-like catalytic activity , which is proven effective in scavenging the free radicals, such assuperoxide anion, hydrogen peroxide, and hydroxyl radical. GQDs are also well praised for its low in vivo and in vitro toxicity. Here, we found that nitrogen-doped GQDs (N-GQDs) can strongly disturb redox-sensitive system via the selective inhibition of endogenous antioxidant enzyme activities in zebrafish. The enzyme activities or transcription levels of a battery of hemoproteins including catalase (CAT), superoxide dismutase (SOD), respiratory chain complex I, complex Ⅲ, hemoglobin (Hb), and myeloperoxidase (MPO), were significantly suppressed by N-GQDs. We also found that N-GQDs activated the cytochrome P450 monooxygenase ( e.g. cyp1a ) and the associated aryl-hydrocarbon receptor repressors ( ahrr1 and ahrr2 ) in zebrafish embryos. Compared to the ultrasmall graphene oxide (USGO), N-GQDs exhibited stronger fluorescent permeability and tissue-specific bio-accumulative effects. Taken together, our findings highlighted that exposure to N-GQDs can disrupt endogenous antioxidant enzyme activities, possibly via the competitive inhibition of electron transfer process. Our results in this study provided solid data for biosafety evaluations of various types of GQDs, and created an alert for the future biomedical applications of N-GQDs.
危险品化学品经营许可证（带存储）