In response to issues identified in the polycyclic aromatic hydrocarbons (PAHs) emission inventory for Guangdong Province—including time-lag, unclear source classification, and ambiguous emission trends—a refined PAHs emission factor library for anthropogenic sources was established through comprehensive literature research. A high-resolution, bottom-up PAHs emission inventory of 16PAH compounds for Guangdong Province covering 2006~2020 was developed using the emission factor method, providing insights into principal emission species, key sources, and the spatiotemporal evolution of emissions. The findings were as follows: From 2006 to 2020, anthropogenic PAHs emissions in Guangdong Province showed an overall decline of 45%, with the contribution of carcinogenic PAHs reducing from 60% to 29%. Naphthalene (Nap), benzo[g,h,i]perylene (Bghip), and phenanthrene(Phe) emerged as the primary PAH species, contributing on average 23%, 10%, and 9% to total PAHs emissions, respectively. As national standards for diesel vehicles and motorcycles tightened, yellow-label vehicles were eliminated, and policies like the prohibition on straw burning were enacted, the primary sources of PAHs emissions shifted from motorcycles, diesel vehicles, and biomass burning to industrial coal combustion, coking, and household combustion. Spatial analysis indicated that line-source emissions (primarily from motorcycles and diesel vehicles) decreased significantly, while point-source emissions from industrial sources increased across several regions. Considering population health risks and the need for targeted PAHs emission controls in densely populated areas, the study recommends enhanced regulation of PAHs from industrial coal combustion and coking industries. This study provides critical scientific support for Guangdong Province′s PAHs emission control strategies, with a focus on public health outcomes.

Monitoring and obtaining observation data of atmospheric anomia is of great significance for further reducing fine particles pollution. The study uses satellite remotely sensed Infrared Atmospheric Sounding Interferometer (IASI) data to conduct research on the accounting method of atmospheric ammonia emission intensity and total ammonia in the Beijing-Tianjin-Hebei and surrounding areas, providing support for the remote sensing monitoring application of atmospheric ammonia and ammonia reduction.Spatial interpolation was performed on spatially discontinuous data to calculate the annual average emission intensity (YNH₃), seasonal average emission intensity (QNH₃), and monthly average emission intensity (MNH₃) of atmospheric ammonia, and to estimate the total amount of atmospheric ammonia (TNH₃). By doing so, the spatial distribution characteristics and temporal variation patterns of atmospheric ammonia in the study area were analyzed, and finally, the influencing factors of atmospheric ammonia emissions were further examined. The results showed that from 2014 to 2022, the daily average emission intensity of atmospheric ammonia in the study area was 7.99kg/km². The central part of the region was a high value area for YNH₃, and the five cities with low column concentrations and low increasing rates were mainly distributed in northern Hebei and southern Henan. The eight cities with low column concentrations but high increasing rates were distributed in southwestern Henan, central Hebei, and Jiaodong Peninsula. The nineteen cities with high column concentrations but low increasing rates and sixteen cities with high column concentrations and high increasing rates were distributed in the central region and the surrounding of the Bohai Sea. Over the past 9 years, both YNH₃ and TNH₃ have shown an increasing trend, with YNH₃ in the study area growing from 5.89kg/km² to 9.20kg/km², with a compound annual growth rate of 5.73%; TNH₃ increased from 1169kt to 1825kt. In terms of temporal distribution, QNH₃ exhibited periodic changes, with summer being the peak season for QNH₃ and July being the peak month for MNH₃. TNH₃ had a high correlation with arable land and population, and their spatial distributions were highly consistent with each other, indicating that farming and population are important influencing factors of ammonia emissions in the study area. Random Forest analysis showed that agricultural and living sources were the most significant reduction factors of ammonia emission. This study demonstrated that remote sensing monitoring of atmospheric ammonia can offer data support for air quality monitoring operations.

The novel PAN/PVDF-HFP/TiO₂ nanofibrous membranes with a high performance in PM_2.5 removal and high-temperature filtration were developed in this study under co-electrospinning-electrospray strategy, with PVDF-HFP/TiO₂ as the functional layer and polyacrylonitrile (PAN) as the base membrane. According to the results, the PHT20nanofibrous membrane achieved an efficiency of 99.8% in capturing particulate matters, a low pressure drop of 67Pa, excellent air permeability, and high thermal stability (to 200℃). Moreover, the results of self-cleaning tests showed that the superhydrophobic surfaces of the PAN/PVDF-HFP/TiO₂ nanofibrous membranes were resistant to dust particle contamination. To sum up, the multifunctional PPHT20 nanofibrous membrane developed in this study is an effective solution to dust removal at high temperatures.

Based on the ground-level ozone (O₃) data from provincial air quality stations and tropospheric HCHO and NO₂ column concentration data from TROPOMI, the spatial and temporal distributions, variation trends and precursor sensitivity of O₃ pollution in Hubei Province from 2019 to 2023 were studied by using the indicator method of O₃ generation sensitivity. The results showed that the concentration of O₃ columns in Hubei Province presented an overall upward trend. For the seasonal variations, the concentrations of O₃ and HCHO were higher in summer and lower in winter, while NO₂ was the opposite. For the spatial distributions, the concentration of O₃ column increased gradually from south to north, and the concentration of NO₂ and HCHO column increased in a stepwise manner from west to east. Through analyzing the spatial distributions of controlling factors for O₃, we found that O₃ generation in most areas of Hubei Province was controlled by NO_x from June to September, and only a small area was controlled by NO_x. Wuhan and its surrounding urban areas in eastern Hubei Province belong to the VOCs-control area, the western Hubei region mainly belongs to the NO_x-control area, the rest of the areas mostly belong to NO_x-VOCs collaborative-control area.After 2019, O₃ generation in eastern Hubei Province has changed from VOCs-control area to NO_x-VOCs collaborative control area.

Three Ru-based catalysts were synthesized using in-situ synthesis, impregnation, and deposition-precipitation methods in combination with MFI zeolites to investigate their catalytic oxidation activity toward propane (C₃H₈). The catalyst synthesized via the in-situ method, denoted as Ru@MFI, exhibited the highest low-temperature oxidation activity, achieving a 90% conversion rate at 270℃, along with remarkable thermal stability at high temperatures and hydrophobicity. Characterization techniques, including X-ray diffraction (XRD), N₂ adsorption-desorption, high-angle annular dark-field scanning transmission electron microscopy(HAADF-STEM), and temperature-programmed desorption of CO (CO-TPD), revealed that Ru confined within the MFI zeolite channels possessed the smallest particle size and highest dispersion, thereby increasing the number of active Ru sites. Further characterization using Raman spectroscopy and hydrogen temperature-programmed reduction (H₂-TPR) indicated that interactions between Ru and the MFI framework led to a redistribution of charge around Ru or oxygen, enhancing the reduction capabilities.Consequently, the Ru@MFI catalyst demonstrated superior propane oxidation activity. Additionally, the geometric confinement within the MFI channels maintained the stability and dispersion of Ru species during high-temperature calcination, effectively preventing Ru aggregation and further ensuring the catalyst's high-temperature thermal stability.

This paper combined multi-source data to develop the identification approach of VOCs high-emission areas during ozone pollution season (from May to September). At the same time, the spatial distribution pattern and long-term change trend of VOCs during the ozone pollution season in Beijing from 2005 to 2023 was examined and discussed based on satellite-derived HCHO column concentration. The results showed that the concentration of VOCs in Beijing is at a high level within the Beijing-Tianjin-Hebei region, and its distribution was significantly affected by human activities. The total amount of HCHO in the areas of anthropogenic sources dominated was 3.4times of that of natural sources dominated. The high emission areas of anthropogenic sources mostly appeared in the northern, central eastern, and southwestern parts of the urban area of Beijing City.Approximately 61% of the areas were sources of industrial production process and solvent usage, and mainly distributed outside the Fifth Ring Road. Approximately 39% of them were sources of automobile maintenance, logistics warehousing etc., and mainly distributed along highways. This identification method has improved the effectiveness of ozone pollution prevention and control work in the summer of 2023, offering technical support for locating key regulatory objects and areas. From the perspective of interannual variations, the column concentration of VOCs in Beijing showed an increasing trend from 2005 to 2018, with an increase of about 26% (after correction of temperature), while it showed a downward trend from 2018 to 2023, with a decrease of about 11%, reflecting the effectiveness of VOCs emission control in recent years.

This study estimated the initial volume mixing ratios of the ambient VOCs measured from 18 April to 31 July 2021 in Linfen, Shanxi Province, using a photochemical age-based parameterization method, and corrected photochemical loss effects.Positive matrix factorization (PMF) was used to conduct the initial-data source apportionment. The results showed that the average volume mixing ratio of total VOCs (TVOCs) during the study period was 17.1×10^-9. The average initial volume mixing ratio of TVOCs in the daytime was 27.2×10^-9, with chemical loss of 10.6×10^-9 and loss rate was approximately 39.0%. Compared with other VOC groups, alkenes had the highest loss rate (66.0%). The chemical losses of isoprene (3.16×10^-9), 1,3-butadiene (1.27×10^-9), and ethylene (1.19×10^-9) were higher than any other species. During the ozone pollution (OP) period, the chemical loss of TVOCs was 15.1×10^-9, which was 1.6times higher than during the non-ozone pollution (NOP) period. During the OP period, the loss rate of alkenes was the highest (81.7%) than the other VOC groups. The losses of isoprene, 1,3-butadiene, trans-2-butene, and trans-2-pentene were 5.05×10^-9, 1.85×10^-9, 1.59×10^-9, and 1.10×10^-9, respectively, substantially higher than any other species. The PMF apportioned results based on the initial volume mixing ratios (i.e., IC-PMF) showed that petrochemical-related enterprise emissions (36.4%), natural gas (17.2%), the mixed source of diesel vehicle emissions and solvent usage (12.9%), gasoline vehicle emissions (9.6%), liquefied petroleum gas (8.6%), biogenic emissions (8.6%), and combustion sources (6.7%) were the main contributors to the ambient VOCs in Linfen during the study period. Compared to the PMF apportioned results based on the observed volume mixing ratios (i.e., OC-PMF), the contribution of biogenic emissions was underestimated by 83.3%, which was substantially higher than those of other sources; followed by the mixed sources of diesel vehicle emissions and solvent usage (22.2%) and the petrochemical-related enterprise emissions (19.7%). Meanwhile, the IC-PMF results suggested that the sources with higher contributions during the OP period were the petrochemical-related enterprise emissions and biogenic emissions, accounting for 24.1% and 21.7%, respectively. According to the IC-PMF apportioned results, the estimated results using the ozone formation potential (OFP) model showed that petrochemical-related enterprise emissions was the highest contributor to the OFP, with the contribution of 50.7% to the total OFP, followed by biogenic emissions (24.8%) and the mixed source of diesel vehicle emissions and solvent usage (10.4%). The emission sources with higher contributions to the OFP during OP period were biogenic emissions and petrochemical-related enterprise emissions, reaching 52.6% and 27.8%, respectively.

This study aims to investigate the VOCs pollution characteristics in the high-tech industrial zone of Tongchuan City, a medium-sized city in the Fenwei Plain, by using online monitoring methods to measure the concentration of environmental VOCs components (a total of 115species) in the atmosphere of the Tongchuan High-tech Industrial Development Zone, thereby obtaining a high-resolution time series and seasonal variation patterns of atmospheric VOCs. The Positive Matrix Factorization(PMF) model was utilized to identify the primary sources of VOCs, and the Maximum Incremental Reactivity (MIR) method was applied to quantify the Ozone Formation Potential (OFP) of VOCs. Furthermore, the Hazard Index (HI) and Lifetime Cancer Risk (LCR) of toxic VOCs were calculated. The findings revealed that during the monitoring period, the average values of φ (TVOCs) in spring, summer, and winter were respectively (69.03 ± 47.48)×10^-9, (92.66 ± 37.54)×10^-9, and (134.90± 74.58)×10^-9, with the top three components in each season being consistent (alkanes > alkenes > aromatics). PMF source apportionment results indicated that the sources of atmospheric VOCs in the development zone were primarily from chemical companies, motor vehicles, and combustion emissions (each contributing over 20%). OFP assessment outcomes revealed that OVOCs were the major contributing components in all seasons, with ethanol, acetaldehyde, and ethylene being the primary species. Health risk assessments indicated that the HI in spring, summer, and winter all exceeded acceptable levels (HI > 1), suggesting non-carcinogenic health risks to the exposed population. Acrolein, in particular, had a notably high hazard index, exceeding 1in all seasons. The lifetime cancer risks in spring, summer, and winter were 1.68×10^-5, 1.57×10^-5, and 8.42×10^-5, respectively, indicating a slight carcinogenic risk in all seasons.

A photocatalytic membrane reaction process, integrating a CBM (gC₃N₄/BiOBr/MXene) photocatalyst and a polyvinylidene fluoride (PVDF) ultrafiltration (UF) membrane, was constructed using a phase inversion method. The addition of CBM was adjusted to optimize the membrane surface structure and properties, as well as to improve the hydrophilicity and permeability of the composite membrane. Tetracycline hydrochloride (TC-HCl), a common antibiotic drug, was used as the target pollutant in the dead-end process to assess the separation and fouling resistance capabilities. The optimally doped PVDF/CBM-0.6membrane achieved 92 % degradation of TC-HCl, in which the active species •O₂^- and h⁺ played a dominant role. The degradation efficiency remains above 85% after 5 cycles, proving its good recyclability. Thirteen degradation intermediates and potential degradation pathways were proposed, including hydroxylation, demethylation, deamination, benzene ring opening, and deamidation reactions. Continuous operation with bovine serum albumin (BSA) confirmed the ability of the process to alleviate irreversible membrane fouling by preventing pore blockage and pollutant adhesion, achieving an efficient membrane self-cleaning.Overall, the CBM/PVDF photocatalytic membrane proposed in this work has the potential to enhance the practical application of photocatalytic membrane reaction systems.

Two typical PA membranes, m-phenylenediamine-trimesoyl chloride and piperazine-trimesoyl chloride, are introduced and their latest chlorine destruction mechanisms are analyzed in depth. On this basis, the chlorine-resistant modification methods for these two membranes are further discussed, including changing the monomer structure, intrinsic doping techniques, physical coating methods and chemical grafting methods. The latest research research advances in the field of chlorinated PA membrane remediation are briefly discussed, including the reduction method after initial chlorination and the remediation with repair agent after chlorination degradation. The analysis shows that the development of chlorine-resistant PA membranes is still facing great challenges, and the research on chlorine-resistant modification of PA membranes should be carried out without sacrificing its separation performance, taking into account all other properties of the membrane, and flexibly utilizing various modification methods.