Search

To investigate human exposure to short-chain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs) through dermal and oral intake via hand-to-mouth contact, wipes from the face, forearm, hand, and foot of 30 volunteers were sampled. The concentration of ∑SCCPs and ∑MCCPs ranged from 0.66 to 119 and 0.71 to 565 µg/m2, respectively. Hands exhibited significantly higher ∑CPs concentrations than other skin areas, indicating that direct contact with indoor surfaces contributed considerable CP levels on this bare skin area. Gender differences in CP levels were observed in wipes from all locations, except for the hands, possibly because of the significant variability in residuals on the hands. A significant positive relationship was found between CP levels on the hands and faces, and the CP ratios of the hands/faces were related to log KOA. Bare skin showed more significant variations in CP partitioning among related congeners and between genders than skin covered by clothing, as elucidated by the linear analysis of RSD and log KOA. Although concentrations on clothing-covered areas were relatively lower than on bare skin, the median estimated dermal absorption doses of ∑SCCPs and ∑MCCPs (152 and 737 ng/kg bw/day, respectively) for the entire body were approximately 1–2 orders of magnitude higher than those for oral ingestion (1.62 and 7.94 ng/kg bw/day, respectively), emphasizing indirect dermal uptake as a significant exposure pathway for humans.

Hexafluoropropylene oxide trimer acid (HFPO-TA) and hexafluoropropylene oxide tetramer acid (HFPO-TeA) are two novel alternatives of perfluorooctanoic acid (PFOA). However, their toxicokinetics and accumulation mechanisms in fish are still unknown. This study provides the first line of in vivo uptake and depuration kinetic, bioaccumulation mechanism and tissue-specific distribution for HFPO-TA and HFPO-TeA, upon a 28-day water exposure and a 14-day depuration in zebrafish (Danio rerio). HFPO-TeA and HFPO-TA could quickly accumulate in zebrafish, and the highest concentrations of HFPO-TeA (15.4 ± 1.6 nmol/g ww), HFPO-TA (4.95 ± 0.19 nmol/g ww) and PFOA (0.47 ± 0.03 nmol/g ww) were consistently present in the blood, which was followed by liver, kidney, intestine, gill, gonad and brain, while the lowest were observed in the muscle (1.01 ± 0.11, 0.16 ± 0.02, and 0.01 ± 0.001 nmol/g ww, respectively), indicating both higher accumulation potentials of both HFPO homologs than their predecessor PFOA. The tissue protein content, rather than lipid content, played an enhancing role in the enrichment of three target chemicals, exhibiting a significant positive correlation (r = 0.735, p = 0.038 for HFPO-TeA; r = 0.770, p = 0.026 for HFPO-TA and r = 0.942, p = 0.001 for PFOA) between the tissue bioconcentration factor (BCF) and the protein contents in corresponding tissues. This phenomenon was validated by the equilibrium dialysis experiment, molecular docking analysis and molecular dynamics simulation, which consistently indicated that the binding affinities of serum and liver proteins were greatest with HFPO-TeA, followed by HFPO-TA and least with PFOA. These results suggested that the binding of the target chemicals to specific proteins determined their tissue-specific accumulation potentials. Nontarget screening by high resolution mass spectrometry (HRMS) did not identify suspicious degradation products for HFPO-TA, implying the strong persistence of HFPO-TA in fish.

In the context of “zero discharge” of mine water and the reverse distribution of coal and water resources in the western mining areas, the direct discharge of high-salinity mine water without proper treatment not only causes immeasurable damage to the local ecological environment, but also leads to serious water resource waste, ultimately constraining the green development of coal industry and the development of ecological civilization. The traditional zero discharge technology for high-salinity wastewater mainly relies on evaporation and crystallization to transform inorganic salts from a solution state to a crystalline state for recovery. From an economic perspective, this technology faces issues such as high investment, high operating costs, and low added value of inorganic salts. Based on this, this paper takes the mine water from a western mine as the raw water, aiming to achieve the resource utilization and desalination of mine water through the membrane integration technology, and focuses on exploring the influence of different operating conditions (operating voltage, feed solution concentration, temperature, acidity and alkalinity, current density, etc.) on the desalination performance of electrodialysis and the acid-base performance of bipolar membrane electrodialysis. Then, based on the experimental data and an economic evaluation model, the economic feasibility is explored, aiming to explore the membrane integration technology suitable for the treatment of high-salinity mine water in the western mining areas, and provide some new research ideas for the development of green resource utilization processes for high-salinity mine water. Through the exploration of the electrodialysis-bipolar membrane electrodialysis experimental process, it is found that the feed solution concentration of the bipolar membrane system should not exceed 80 g/L, the appropriate operating voltage is 18 V, the suitable feed solution temperature is 25 ℃, the feed solution pH should be kept neutral, and constant voltage operation is more suitable. In addition, it is confirmed that the membrane integration system centered on bipolar membrane electrodialysis can achieve the green resource utilization of high-salinity mine water. Taking the total salt content of the electrodialysis system feed solution as an example (20 g/L), the overall net profit is ￥18604299 per year, and it has a significant carbon dioxide emission reduction effect when coupled with a photovoltaic power supply system, with a carbon dioxide emission reduction of over 3162 tons per year, demonstrating good economic and social benefits.

Coal is the main energy source in China, and the western region in China is the main coal production area. The protection and utilization of coal mine water is the major technical challenge in the coal mining. The coal green mining research team of China Energy Group has pioneered the technology of underground coal mine reservoirs, which has been widely implemented in the Shendong mining area in Western China, providing over 95% of water needed for mining and ensuring the sustainable development of the mining area. To further enrich and improve the theoretical and technical system of underground coal mine reservoirs, this technology has been promoted and applied under different geological and working conditions in the western coal mining areas to ensure national energy security and water resources protection. The research team has built the original technology experimental platform system for coal mine underground reservoirs, including the comprehensive intelligent experimental platform for underground water transport and protection, the physical modelling platform for coal mine underground reservoirs under multiple coal seams, the dam structure experimental platform for coal mine underground reservoirs, the simulation experimental platform for deep well construction in western areas, the water-rock coupling mechanism experimental platform for underground water reservoirs, the integrated water treatment process experimental platform, and the impact experimental platforms for coal mine underground reservoirs, etc. On these platforms, the researches can be carried out consisting of the transport law of underground water, the optimization of dam structure parameters, the safety and stability of reservoirs, water-rock coupling mechanism, the optimization of mine water treatment, and the impact of caving rock mass on the dam structure under different coal seam occurrence conditions in the western mining areas of China. These platform systems provide a theoretical support and technical verification for the construction, operation, and safety of coal mine underground reservoirs. By utilizing these experimental platforms, various experimental research studies have been conducted, including the stability and seepage of coal mine underground reservoirs under multiple coal seams, the structural safety of coal mine underground reservoirs dam, and the water-rock coupling mechanism of coal mine underground reservoirs. These research results have been applied in actual engineering practice to ensure the safe and stable operation of coal mine underground reservoirs.

Underground reservoir technology for coal mines can realize the coordinated development of coal exploitation and water protection in water-shortage-prone areas. The seepage effect of the floor seriously affects the safety of underground reservoirs under the action of mining damage and seepage pressure. Focusing on the problem of floor seepage in underground reservoirs, a spatial mechanical model of underground reservoirs was established. The main factors affecting the seepage of the surrounding rock were studied. The seepage pressure law in different stages of spatial structure evolution of overlying strata was explored. The results showed that pressure change was the main factor affecting the stability of a reservoir's surrounding rock. The pore space between the broken and fractured rock in the water-flowing fractured zone was the main water storage space, which was directly related to the development of a breaking arch. According to the spatial structure evolution process of the overlying strata, the water storage state of an underground reservoir was divided into two stages and three situations. The seepage pressure was mainly affected by the water pressure and the overlying strata weight. The water pressure was affected by the reservoir head height, and the overlying strata weight was mainly affected by the overlying strata thickness.

Organophosphate esters (OPEs) are a group of pollutants that are widely detected in the environment at high concentrations. They can adversely affect human health through multiple routes of exposure, including dermal uptake. Although attention has been paid to achieving an accurate and complete quantification of the dermal uptake of OPEs, existing evaluation methods and parameters have obvious weaknesses. This study reviewed two main categories of methodologies, namely the relative absorption (RA) model and the permeability coefficient (PC) model, which are widely used to assess the dermal uptake of OPEs. Although the PC model is more accurate and is increasingly used, the most important parameter in this model, the permeability coefficient (Kp), has been poorly characterised for OPEs, resulting in considerable errors in the estimation of the dermal uptake of OPEs. Thus, the detailed in vitro methods for the determination of Kp are summarised and sorted. Furthermore, the commonly used skin membranes are identified and the factors affecting Kp and corresponding mechanisms are discussed. In addition, the experimental conditions, conclusions, and available data on Kp values of the OPEs are thoroughly summarised. Finally, the corresponding knowledge gaps are proposed, and a more accurate and sophisticated experimental system and unknown Kp values for OPEs are suggested.

Herein, the trapping effectiveness of N95, filter KN95, medical surgical masks (MSMs), and disposable medical masks (DMMs) against 19 airborne traditional and novel organophosphate esters (OPEs) was evaluated. Laboratory simulations (n = 24 for each type of mask) showed that time-dependent accumulation of ∑19OPEs on the four types of masks ranged between 30.1 and 86.6 ng in 24 h, with the highest and lowest median amounts trapped by the N95 masks (53.3 ng) and DMMs (43.2 ng), respectively. The trapping efficiency of the four types of masks for ∑19OPEs decreased over time from 84 % to 39 % in 24 h, with N95 masks showing the highest median efficiency (70 %). Further, field investigations were conducted in five types of microenvironments (train, hospital, bus, supermarket, and canteen), and an analysis of 200 samples showed that ∑19OPEs were accumulated in the masks with a variable amount from 3.7 to 117 ng/mask. Consistent with the laboratory simulations, the N95 masks (29.0 ng/mask) exhibited the highest hourly median amount of trapped OPEs, followed by the KN95 masks (24.5 ng/mask), MSMSs (17.4 ng/mask), and DMMs (15.8 ng/mask). Triethyl phosphate (TEP), tris(1-chloro-2-propyl) phosphate (TCIPP), tri-n-butyl phosphate (TNBP), and cresyl diphenyl phosphate (CDP) as well as 4-isopropylphenyl diphenyl phosphate (4IPPDPP) and 2,4-diisopropylphenyl diphenyl phosphate (24DIPPDPP) were the most commonly detected traditional and novel OPEs. Based on the amount of OPEs trapped on the masks, we estimated the concentration of ∑19OPEs in the train microenvironment to be the highest (222 ng/m3), which is approximately 2–5 times higher than that in the other microenvironments. The results of this study prove that masks can effectively protect humans from exposure to OPEs and act as low-cost indicators of indoor contamination.

This study focuses on the seismic safety of distributed underground reservoirs in coal mines, especially in scenarios involving the establishment of multiple reservoirs within the same mining area, spanning different coal seams. Dynamic similarity model tests and numerical simulations are employed to investigate the construction and operation of these reservoirs under extreme conditions, such as mine tremors or earthquakes. Utilizing the Daliuta coal mine underground reservoir as a case study, a similarity material model test platform is established to represent both upper and lower coal mine underground reservoirs. Stability tests are conducted on the interlayer rock mass under various levels of seismic intensity, and the safety of the interlayer rock mass at different safety distances is comparatively analyzed. Meanwhile, using the finite element method, the responses of the upper and lower coal mine underground reservoirs under different seismic intensity levels are simulated with the same conditions of model tests. Through the two types of simulations, the mechanical response and safety of the surrounding rock of the Daliuta coal mine underground reservoir under the influence of different seismic intensities are systematically analyzed, and the reasonable safety distances between the upper and lower reservoirs are obtained. This study provides a valuable scientific insight into the safe design of underground reservoir embankments in coal mines.