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The mechanisms governing pore development, particularly of organic pores, in marine–continental transitional shales remain poorly constrained. This study investigated the primary controls on pore evolution within transitional shales of the Benxi Formation using low-pressure gas adsorption, field emission scanning electron microscopy, bulk mineralogy and maceral analyses, and other techniques. Total organic carbon (TOC) contents exhibit positive correlations with shale microporosity and negative correlations with macroporosity. On the basis of S/TOC ratios and sedimentological evidence, the Benxi shales accumulated across a range of marine, brackish, and freshwater depositional environments. In general, more negative δ13Ckerogenvalues correlate with higher S/TOC, consistent with a marine source for the most 13C-depleted kerogens. Kerogens with δ13C of < –25‰ reflect a marine origin, while those with δ13C of > –25‰ indicate varying salinity conditions. Both organic matter composition and pore development within type III kerogens proved highly sensitive to paleosalinity. Specifically, marine-sourced organic matter possesses substantially lower microporosity but higher meso- and macroporosities compared to material deposited in freshwater settings. Accordingly, thermally mature marine-influenced Benxi shales likely retain greater shale gas potential versus non-marine equivalents.

Fluorinated liquid crystal monomers (FLCMs) have been suggested as emerging contaminants, raising global concern due to their frequent occurrence, potential toxic effects, and endurance capacity in the environment. However, the environmental fate of the FLCMs remains unknown. To fill this knowledge gap, we investigated the aerobic microbial transformation mechanisms of an important FLCM, 4-[difluoro(3,4,5-trifluorophenoxy)methyl]-3, 5-difluoro-4′-propylbiphenyl (DTMDPB), using an enrichment culture termed as BG1. Our findings revealed that 67.5 ± 2.1% of the initially added DTMDPB was transformed in 10 days under optimal conditions. A total of 14 microbial transformation products obtained due to a series of reactions (e.g., reductive defluorination, ether bond cleavage, demethylation, oxidative hydroxylation and aromatic ring opening, sulfonation, glucuronidation, O-methylation, and thiolation) were identified. Consortium BG1 harbored essential genes that could transform DTMDPB, such as dehalogenation-related genes [e.g., glutathione S-transferase gene (GST), 2-haloacid dehalogenase gene (2-HAD), nrdB, nuoC, and nuoD]; hydroxylating-related genes hcaC, ubiH, and COQ7; aromatic ring opening-related genes ligBand catE; and methyltransferase genes ubiEand ubiG. Two DTMDPB-degrading strains were isolated, which are affiliated with the genus Sphingopyxisand Agromyces. This study provides a novel insight into the microbial transformation of FLCMs. The findings of this study have important implications for the development of bioremediation strategies aimed at addressing sites contaminated with FLCMs.