A considerable quantity of microplastic debris exists in the environment and the toxicity of these materials has a notable impact on aquatic ecosystems. In this paper, 50–500 µm polystyrene microplastics (exposure concentrations were 200 µg/L, 800 µg/L, and 3200 µg/L concentrations) were selected to study the effects of polystyrene microplastics (PS-MPs) on cell morphology, detoxification enzyme activity, and mRNA expression in the liver tissues of crucian carp juveniles. The results demonstrated that: (1) Different concentrations of PS-MPs cause varying degrees of pathological and oxidative damage to liver tissue cells of crucian carp. The higher the concentration of microplastics, the lower the antioxidant enzyme (CAT, GST, SOD) activity and the greater the tissue cell damage. These results demonstrate a typical dose–effect relationship. (2) Principal component analysis and Spearman’s correlation analysis demonstrated that four components, namely glutathione S-transferase (GST) and its related genes (GSTpi, GSTα), along with catalase (CAT), contributed the most to the observed outcome. These four components demonstrated a relatively high level of responsiveness to PS-MP exposure and can be employed as ecotoxicological indicators of microplastics. (3) This experiment evaluated five genes in three treatments, which found that PS-MPs had different effects on gene expression in the liver and the tested genes were involved in different response pathways associated with virulence. In this study, the toxicity of PS-MPs to crucian carp was determined at the cellular, protein, and mRNA expression levels, and combined with principal component analysis and correlation analysis to identify response sensitivity indicators that provide a scientific basis for ecological risk assessment and the safe use of microplastics.

To conduct an environmental risk assessment for metals in the groundwater of a site in Jiujiang City, Jiangxi Province, we analyzed seven metals (Cr, Zn, Pb, Ni, Sb, Cu, and Tl) that exhibited higher detection rates among the elements we measured. For example, in our measurement data, the average concentration of the element cobalt (Co) is less than 2 × 10^–3 μg/L, and the average concentration of the element cadmium (Cd) is less than 5 × 10^–3 μg/L. The purpose of this environmental risk assessment was to provide a scientific basis for site remediation and subsequent construction. The risk assessment was carried out using the single-factor pollution index, the Nemerow comprehensive pollution index (Pn), and potential ecological hazard index methods. Principal component analysis and correlation analyses were used to investigate the sources of metal pollution in the groundwater. The results indicated the following: (1) The average concentrations of the seven metals in the groundwater of the study area did not exceed the Class IV groundwater quality standard limits. The highest average concentration was for Zn (38.08 μg/L), indicating that metal concentrations in the groundwater were relatively low. (2) The Pn for the seven metals was below 0.7, indicating that the study area was at a non-polluted level. (3) The correlation and principal component analyses of the metals indicate that the sources of these metals may be residues from material stored in the raw material warehouse of the former iron smelting plant at the site. The results show that the level of groundwater contamination at the site falls within an extremely low range; thus, the focus on groundwater pollution can be reduced in subsequent site remediation and construction activities.

A novel composite biomass aerogel adsorbent (HSA) was prepared by dual physical and chemical cross-linking using sodium alginate (SA) as an organic biomass template and hydroxyapatite nanowires (HAPNWs) as an inorganic biomass skeleton. The structure of the HSA was characterized by scanning electron microscopy (SEM), X-ray powder diffractometry (XRD), Fourier transformed infrared spectroscopy (FTIR), and stress testing. One-factor experiments were conducted focusing on adsorption conditions at a Pb ion concentration of 300 mg/L, and the adsorption conditions were optimized using the response surface method. The optimal conditions obtained by numerical optimization using Design-Expert 13 were as follows: pH of 7.23, adsorption temperature of 35.42 °C, and adsorption time of 1050.73 min; the optimal adsorption capacity was 278.874 mg/g. To further reveal the adsorption mechanism of HSA, its adsorption model and kinetics were analyzed. Adsorption was most consistent with the Langmuir isothermal adsorption model, while the kinetics were most consistent with the pseudo-secondary kinetic model. R² reached 0.9986, indicating a mono-molecular layer of adsorption by heat, while the main adsorption mechanism was chemisorption.

This study analyzed three years of data (2021–2024) from three wastewater treatment plants (WWTPs), namely D, X, and T, in the main urban area of Handan, a typical city in the southern Hebei region, and investigated the influent characteristics and impact of temperature on these wastewater treatment facilities. With 90% assurance, the overall influent conditions of the three WWTPs in this region were normal. However, Plant T operated more effectively with slightly lower BOD₅/COD_Cr (B/C), organic carbon/total phosphorus (C/TP), and organic carbon/total nitrogen (C/TN) ratios in the influent. Plant D consistently met the Level A standard, Plant X essentially reached the Level A standard, while Plant T attained the Level 2 standard prior to its upgrade. Following the upgrade, Plant T also steadily met the Level A standard. The effluent from all plants was relatively stable, primarily influenced by the influent characteristics and slightly influenced by temperature, but without having a noticeable impact on the effluent quality.