Forecasting the PAH concentration in the soil of Beijing gas stations for 2025 and 2030 was accomplished via a BP neural network approach. The seven PAHs, in total, had concentrations found to be between 0.001 and 3.53 milligrams per kilogram in the results. The concentrations of PAHs in the soil, concerning development land (Trial) contamination, complied with the environmental quality risk control standard specified by GB 36600-2018. The toxic equivalent concentrations (TEQ) of the seven previously cited polycyclic aromatic hydrocarbons (PAHs) were simultaneously lower than the World Health Organization's (WHO) 1 mg/kg-1 limit, indicating a reduced risk for human health. The prediction outcomes revealed a positive relationship between the swift expansion of urbanization and the augmented concentration of polycyclic aromatic hydrocarbons (PAHs) in the soil. Beijing's gas station soil will see a continued enhancement in PAH content before 2030. For 2025 and 2030, the predicted PAH concentrations in the soil at Beijing gas stations were found to be between 0.0085-4.077 mg/kg and 0.0132-4.412 mg/kg, respectively. While the concentration of seven PAHs fell below the soil pollution risk screening threshold of GB 36600-2018, a concerning rise in PAH levels was observed over time.
In Yunnan Province, near a Pb-Zn smelter, 56 surface soil samples (0-20 cm) were gathered. Analysis of these samples for six heavy metals (Pb, Cd, Zn, As, Cu, and Hg), along with pH values, allowed for an evaluation of the heavy metal status, ecological risk, and potential probabilistic health risks within agricultural soils. A statistical analysis of the data showed that average contents of six heavy metals (Pb441393 mgkg-1, Cd689 mgkg-1, Zn167276 mgkg-1, As4445 mgkg-1, Cu4761 mgkg-1, and Hg021 mgkg-1) were higher than the background levels observed in the Yunnan Province. Cadmium stood out with the highest mean geo-accumulation index (Igeo) of 0.24, the largest mean pollution index (Pi) of 3042, and the utmost average ecological risk index (Er) of 131260. This unequivocally designates cadmium as the chief enriched pollutant and the one posing the most significant ecological risk. selleckchem Exposure to six heavy metals (HMs) resulted in a mean hazard index (HI) of 0.242 and 0.936 for adult and child populations, respectively. Critically, 36.63% of children's HI values surpassed the 1.0 risk threshold. Additionally, the mean total cancer risks (TCR) calculated for adults and children were 698E-05 and 593E-04, respectively. A substantial 8685% of the child TCR values surpassed the regulatory threshold of 1E-04. Cd and As emerged as the significant contributors to non-carcinogenic and carcinogenic risks, as suggested by the probabilistic health risk assessment. The scientific conclusions of this work will inform the development of a precise risk management approach and a successful remediation strategy for heavy metal pollution in this examined area of soil.
In order to ascertain the pollution profile and pinpoint the origin of heavy metal contamination in the soil of farmland surrounding the coal gangue heap in Nanchuan, Chongqing, the Nemerow pollution index and the Muller index served as analytical tools. In order to determine the sources and contribution rates of heavy metals present in the soil, the analytical tools of absolute principal component score-multiple linear regression receptor modeling (APCS-MLR) and positive matrix factorization (PMF) were applied. The study found higher quantities of Cd, Hg, As, Pb, Cr, Cu, Ni, and Zn in the downstream region compared to the upstream area; however, a statistically substantial increase was only detected for Cu, Ni, and Zn. According to the pollution source analysis, copper, nickel, and zinc pollution were primarily attributable to mining operations, encompassing the extended presence of coal mine gangue heaps. APCS-MLR model analysis displayed contribution rates of 498%, 945%, and 732% for these elements, respectively. Proliferation and Cytotoxicity The PMF contribution rates were, respectively, 628 percent, 622 percent, and 631 percent. The elements Cd, Hg, and As were primarily affected by agricultural and transportation activities, with respective APCS-MLR contribution percentages of 498%, 945%, and 732%, and PMF contribution rates of 628%, 622%, and 631%. In addition, natural elements played the major role in affecting lead (Pb) and chromium (Cr), with respective APCS-MLR contribution percentages of 664% and 947%, and PMF contribution percentages of 427% and 477%. Analysis of the source data revealed a fundamental similarity in outcomes when using the APCS-MLR and PMF receptor models.
For maintaining a healthy and sustainable farmland ecosystem, the identification of heavy metal sources in soils is indispensable. Employing the outcome of a positive matrix factorization (PMF) model, encompassing source component spectra and source contributions, coupled with historical survey data and time-series remote sensing data, this study integrated geodetector (GD), optimal parameters-based geographical detector (OPGD), spatial association detector (SPADE), and interactive detector for spatial associations (IDSA) models to investigate the modifiable areal unit problem (MAUP) affecting the spatial heterogeneity of soil heavy metal sources. The study further determined the driving factors and their interactive influences on the spatial heterogeneity of soil heavy metals, considering both categorical and continuous variables. The study's results indicated that the spatial scale influenced the spatial heterogeneity of soil heavy metal sources at small and medium scales, and the most suitable spatial unit for this detection was determined to be 008 km2 within the study region. To analyze the spatial heterogeneity of soil heavy metal sources, the quantile method, combined with discretization parameters and an interruption count of 10, might lessen the partitioning effects on continuous variables. This approach considers the intricate interplay of spatial correlation and discretization level. Soil heavy metal source spatial heterogeneity was modulated by strata categories (PD 012-048). The combined effect of strata and watershed classifications explained 27.28% to 60.61% of the variability in each source. High-risk zones for each source were concentrated in the lower Sinian system strata, the upper Cretaceous strata, mining land, and haplic acrisol soil types. Soil heavy metal source spatial variation, within the context of continuous variables, was influenced by population (PSD 040-082), with the explanatory power of spatial combinations of continuous variables varying between 6177% and 7846% for each source. The following factors were distributed within high-risk areas in each source: evapotranspiration (412-43 kgm-2), distance from the river (315-398 m), enhanced vegetation index (0796-0995), and a second measure of distance from the river (499-605 m). The research outcomes serve as a guide for exploring the drivers of heavy metal origins and their effects in arable soils, laying a strong scientific foundation for responsible arable land management and sustainable growth in karst environments.
Ozonation has become integrated into the established protocol for advanced wastewater treatment. During the development of advanced ozonation-based wastewater treatment, researchers are required to thoroughly evaluate the effectiveness of emerging technologies, reactors, and materials. The choice of appropriate model pollutants to evaluate the capacity of novel technologies to remove chemical oxygen demand (COD) and total organic carbon (TOC) from practical wastewater specimens often mystifies them. The extent to which pollutants, as described in the literature, can reflect actual COD/TOC removal in wastewater samples is unclear. Developing a technological framework for advanced ozonation wastewater treatment demands careful consideration of model pollutant selection and evaluation procedures within the context of industrial wastewater. The investigation included ozonation under identical parameters of aqueous solutions, containing 19 model pollutants and four practical secondary effluents from industrial parks, both unbuffered and bicarbonate-buffered solutions. The preceding wastewater/solutions' similarities in COD/TOC removal were evaluated using clustering analysis as the principal method. Study of intermediates The data showed that the model pollutants exhibited a greater degree of dissimilarity compared to the actual wastewaters, permitting a strategic selection of specific model pollutants to evaluate the effectiveness of advanced wastewater treatment using varied ozonation procedures. In predicting the removal of COD from secondary sedimentation tank effluent via 60-minute ozonation, using unbuffered aqueous solutions of ketoprofen (KTP), dichlorophenoxyacetic acid (24-D), and sulfamethazine (SMT) yielded prediction errors of less than 9%. Significantly lower prediction errors, less than 5%, were observed when using bicarbonate-buffered solutions of phenacetin (PNT), sulfamethazine (SMT), and sucralose. The pH evolution, using bicarbonate-buffered solutions, showed a greater resemblance to that seen in real-world wastewater applications than using unbuffered aqueous solutions. In assessing the removal of COD/TOC using ozone in bicarbonate-buffered solutions versus practical wastewaters, the results were practically identical, irrespective of differing ozone concentrations. Accordingly, the similarity-based protocol for evaluating wastewater treatment performance, as presented in this study, can be extended to different ozone concentration conditions, demonstrating a degree of universality.
Currently, microplastics (MPs) and estrogens stand as prominent emerging contaminants, with MPs potentially acting as estrogen carriers in the environment, leading to combined pollution. The adsorption behavior of polyethylene (PE) microplastics concerning typical estrogens, including estrone (E1), 17β-estradiol (17β-E2), estriol (E3), diethylstilbestrol (DES), and ethinylestradiol (EE2), was investigated through batch adsorption experiments under equilibrium conditions. The adsorption was examined in both single-component and mixed-component systems. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) were utilized for characterizing the PE microplastics before and after the adsorption process.