This research involved synthesizing a novel UIO-66-NH₂@Ti₃C₂ composite through a one-step hydrothermal process, followed by calcination at 300 °C under argon and exploring its potential for the electrochemical detection of acetaminophen.

A reversed migration capillary electrophoresis (RMCE) has been developed to determine linear alkylbenzene sulfonates (LAS). The sample stacking and separation conditions have been systematically investigated and optimized under reversed separation voltage at a low pH value. The separation effect of LAS homologs has been greatly improved based on the relative motion of electrophoresis and electroosmotic flow. RMCE demonstrates a good linear range of 0.1 mg/l to 10.0 mg/l, and the detection limit of LAS homologs reaches 0.001–0.004 mg/l. The relative standard deviations (n=6) of peak area and migration time were 2.25–4.40% and 0.67–0.75%, respectively. RMCE has also been applied for LAS detection in practical wastewater. The results show RMCE exhibits easy pretreatment, fast detection, high sensitivity, good peak shapes and resolution, and less solvent consumption, compared with the established high-performance liquid chromatography method.

Ionic surfactants are easily adsorbed by silt and clay particles, thus affecting the flocculation characteristics and settling behavior. The settling velocity, typical size, Zeta potential and surface tension of silt flocs were measured in the presence of two different kinds of ionic surfactants. The results indicated that the cetyltrimethylammonium bromide (CTAB, a typical cationic surfactant) can dramatically accelerate the settling of slit particles, while the linear alkylbenzene sulfonate (LAS, a typical anionic surfactant) slightly retarded silt sedimentation to some extent. In still water, the representative settling velocity dramatically increased from 0.36 cm s⁻¹ to 0.43 cm s⁻¹ with the increase of CTAB concentration, which increased by more than 20%. Oppositely, the sedimentation rate decreased from 0.36 cm s⁻¹ to 0.33 cm s⁻¹ with the increase of LAS concentration. In flowing water, as the flow rate increased from 0 to 20 cm s⁻¹ and the ionic surfactant concentration increased from 0 to 10 mg L⁻¹, the sedimentation rate decreased to 57% and 89% in the presence of CTAB and LAS respectively, which was due to an enhanced dispersion of silt particles and a breaking of flocs. The SEM image test shows that the floc particle size increased 1.5 times of the primary particle size under the high CTAB concentration. The flocculation induced by ionic surfactants greatly influences the sediment size as well as the law of settling velocity. The intrinsic influence mechanism was also discussed based on the variations of silt particle properties. This systematic study can be used for further development of flocculation models and particle size distribution of fine-grained soil.

To investigate the impact of periodic water-level fluctuations on soil microbial community structure in the riparian zone of the Three Gorges Reservoir Area, this study focused on the riparian zone at Zhangjiawan near the dam. Surface soil samples (0–20 cm) were collected in spring, summer, and autumn from three elevation gradients: below 160 m, 160–170 m, and above 170 m. Phospholipid fatty acid (PLFA) was employed to characterize the microbial community structure. The results indicated that microbial community distribution was significantly influenced by both elevation and season, with bacteria dominating community variations. In terms of elevation, the total microbial biomass and bacterial abundance were highest at the 160–170 m gradient, followed by the area above 170 m, and lowest below 160 m. Season and elevation exhibited a significant interactive effect on fungi. Seasonal patterns showed that total microbial biomass and bacterial abundance peaked in summer, whereas fungal abundance and the fungi-to-bacteria ratio were higher in autumn. In contrast, actinobacterial abundance remained stable across seasons. Soil organic carbon (SOC; 60.3%) was identified as the predominant environmental factor influencing microbial community structure, followed by total nitrogen (TN; 13.9%) and pH (2.4%). SOC was identified as the key driver of microbial community dynamics. These findings clarify the respective roles of water level fluctuation, seasonal variation, and environmental factors in shaping riparian microbial communities, providing critical baseline data and theoretical support for ecological protection and scientific management of the Three Gorges Reservoir Area.

Dissolved organic matter (DOM) plays a key role in shaping lake microbiomes and water quality, yet its spatial variability and regional links to microbial activity remain unclear. Using three-dimensional excitation–emission matrix and self-organizing map analysis on 38 samples from a human-impacted lake network in Hubei (affected by tourism, agriculture, and urban areas), this study clarifies DOM heterogeneity and its environmental connections. Microbial metabolic activity represented by total bacterial content (BC) and Escherichia coli (E. coli) activity was rapidly and automatically measured with a ColiMinder device. Random forest (RF) modeling and principal component analysis (PCA) were applied to identify key drivers of microbial activity and to clarify correlations between DOM characteristics and microbial activitiy. Results indicated that although DOM in all three sectors primarily originated from microbial activities during the flat-water period, Tuanhu (TH) exhibited a higher degree of DOM humification and a larger average relative molecular mass, reflecting stronger terrestrial source characteristics. RF analysis identified NH₄⁺ as the main predictor of both BC and E. coli levels, while total organic carbon (TOC) and total nitrogen (TN) were also important predictors. PCA further revealed clear differences in DOM composition across the lakes. DOM in TH was predominantly autochthonous, whereas DOM in Miaohu (MH) and Guozheng (GZ) was mainly of humic origin. This study adopts an integrated method combining rapid microbial detection, EEM and DOM–microbe correlation analysis to analyze human disturbances across segmented connected lakes in Hubei. It provides scientific support for targeted water quality management of human-influenced freshwater.

Soil organic carbon (SOC) and its active fractions—labile organic carbon (Lab-C), dissolved organic carbon (DOC), and microbial biomass carbon (MBC)—govern soil carbon stability and climate feedback mechanisms. To investigate the distribution patterns and regulatory mechanisms of SOC and those active fractions along elevational gradients in the riparian zone of the Three Gorges Reservoir Area (subjected to intense waterlogging stress), soil sampling and analysis were conducted across four zones of the Longtanping: below 160 m, 160–170 m, 170–180 m, and above 180 m in early September 2021. Results indicated that as elevation increases, the content of SOC and active components exhibited a unimodal distribution pattern showing initial increases followed by decreases; moreover, this pattern can be attributed to the pH-riven changes in bacterial abundance under varying inundation stress conditions. The peak values occurred at elevations of 160–170 m, with the overall distribution pattern being as follows: 160–170 m > 170–180 m > above 180 m > below 160 m. Correlation analysis revealed significant positive correlations among SOC, DOC, MBC, Lab-C, pH, TN, and bacterial abundance (p < 0.05). Lab-C demonstrated the strongest explanatory power for SOC variations, serving as a sensitive indicator of SOC turnover and persistence dynamics. This study provides critical insights into the carbon cycling mechanism and regional carbon sink assessment in reservoir riparian ecosystems.