Fine particulate matter (PM2.5) and ozone (O3) are the primary air pollutants that degrade air quality in China. Reducing precursor emissions reasonably, volatile organic compound (VOC) and nitrogen oxides (NOx), are the keys to achieving effective improvement of air quality. To better tackle this challenge, we revealed the nonlinear response of PM2.5 and O3 concentrations to precursor reduction from various sources in Shandong, China using the Weather Research and Forecasting-Comprehensive Air Quality Model Extensions (WRF-CAMx) models and Empirical Kinetics Modeling Approach (EKMA). VOC reductions from all sources presented a positive effect in reducing PM2.5 and O3 concentrations in four seasons, while both levels showed a trend of first increasing and then decreasing as the proportion of NOx reduction increased, except in summer. Focusing on VOC emissions reduction first is critical for reducing PM2.5 concentrations and the long-term improvement in PM2.5 requires strengthening the deep emission reduction of NOx. The reduction ratios of VOC and NOx emissions from all sources with 3:1 in spring and autumn, and 1:2 in summer were more conducive to reducing O3 concentrations. The reasonable emission reduction ratios of VOCs and NOx from industry, power, transportation, and residential sources were also evaluated. For example, the reduction ratios of VOC and NOx emissions with 2:1 from industry and residential, and 1:2 from power and transportation are beneficial for decreasing PM2.5 concentrations. This study offers valuable insights for formulating rational and effective PM2.5 and O3 control strategies.

Ozone (O3) is the primary air pollutant that degrades air quality in China. However, the combined effects of pollution levels and durations on O3 characteristics, as well as sensitivity variations between months within a season, remain unclear. To address this, we analyzed the spatio-temporal distribution, sensitivity regimes, and sources of O3 pollution in southeastern Shandong Province in 2019-2022. The random forest model indicated that meteorological condition was the dominant factor leading to the variation of O3 concentration decreasing in 2019-2021 but rebounding in 2022. The O3 concentrations increased with the duration of pollution and the concentration of O3 pollution lasting for >= 3 days exhibited a year-on-year increasing trend. The O3 concentrations under the same pollution level have not changed much from 2019 to 2022, while the number of days with mild O3 pollution fluctuated in 2019-2022 influenced by temperature, humidity, and anthropogenic emissions. O3 generation sensitivity exhibits strong monthly variations and spatial distribution, which requires strengthening volatile organic compound emission control during March and April, and NOx emission control in July. The results of O3 sources indicated that trajectories originating from the southeast of Ju County exerted influences on O3 concentration. With the increase in O3 pollution duration, the dominant potential source regions continued to expand. The dominant potential source regions during moderate pollution were larger and more focused than those during mild pollution, mainly in Jiangsu Province. Our findings provide a reference for the precise control of O3 pollution.

Despite significant progress in air quality improvement, heavy fine particulate matter (PM2.5) pollution events persist in China. The pollution characteristics of PM2.5 vary during different pollution levels, highlighting the necessity for a deeper understanding of its underlying driving factors and regional transport. This study systematically investigated the compositional characteristics, drivers, and regional transport of PM2.5 in Linyi by integrating multi-data fusion analysis, positive matrix factorization-machine learning-shapley additive explanation (PMF-ML-SHAP), and concentration weighted trajectory model. The results revealed that heterogeneous reactions dominated SO42 - formation during polluted periods, while homogeneous reactions drove NO3- formation. In constructing the integrated PMF-ML-SHAP framework, RandomizedSearchCV and KFold techniques significantly enhanced CatBoost model performance. The contribution of local sources increased progressively from 85.6 % to 91.4 % with rising PM2.5 levels, with secondary nitrate formation emerging as the dominant driver of PM2.5 pollution. The influence share of biomass combustion was higher during clean (CP, 20.4 %) and slightly polluted periods (SPP, 17.3 %), while that of firework combustion was higher during heavily polluted periods (HPP, 25.9 %). Among meteorological factors, wind speed and ultraviolet radiation intensity played critical roles in PM2.5 dispersion and secondary aerosol formation. Regional transport analysis indicated that short-range and medium-range transport air masses primarily influenced CP and SPP, whereas local transport air masses dominated during moderately polluted periods (MPP, 54.4 %) and HPP (58.2 %). This study provides new insights into the drivers of PM2.5 pollution during different pollution levels, offering a scientific basis for targeted pollution control strategies in Linyi and similar industrial cities.

China has successively put forward ultra-low emission (ULE) transformation plans to reduce the air pollutant emissions of industrial pollutants since 2014. To assess the benefits of the ULE policy on regional air quality for Qinhuangdao, this study developed an emission inventory of nine atmospheric pollutants in 2016 and evaluated the effectiveness of the emission policy in Qinhuangdao's key industries under different scenarios with an air quality model (CALPUFF). The emissions of air pollutants in 2016 were as follows: Sulfur dioxide (SO2) emitted 48.91 kt/year, nitrogen oxide (NOx) emitted 86.83 kt/year, volatile organic compounds (VOCs) emitted 52.69 kt/year, particulate matter (PM10 and PM2.5) emitted 302.01 and 116.85 kt/year, carbon monoxide (CO) emitted 1208.80 kt/year, ammonia (NH3) emitted 62.87 kt/year, black carbon (BC) emitted 3.79 kt/year, and organic carbon (OC) emitted 2.72 kt/year, respectively. The results showed that at the regional level in 2025, the iron and steel industry under the PPC (Peak Production Capacity) scenario had the highest potential for reducing SO2 and NOx emissions, while the cement industry under the PPC scenario excelled in reducing PM10 emissions. As for the industrial level in 2025, the flat glass industry under the ULE scenario would reduce the most SO2 emitted, while the iron and steel industry and the cement industry under the PPC scenario demonstrated the best reduction in NOx and PM10 emissions, respectively. Furthermore, the average annual contribution concentration of SO2, NOx, and PM10 in the air monitoring stations of Qinhuangdao under the PPC scenario was significantly lower than that under the BAU scenario revealed by air quality simulation. It can be concluded that the emission policy in Qinhuangdao will help improve the air quality. This study can provide scientific support for policymakers to implement the ULE policy in industrial undeveloped cities and tourist cities such as Qinhuangdao in the future.

Accurate meteorological fields and applicable air quality models are important ways to optimize air pollution simulations. To improve the accuracy of winter air pollution models in the Sichuan basin, we conducted a meteorological field simulation using 25 sets of parameterized scheme combinations in the Weather Research and Forecasting (WRF) Model. Based on the optimal parameters, the air pollution levels were simulated using AERMOD and CALPUFF models in a local large steel plant, and the data were verified by comparing the data from four National Ambient Air Monitoring Stations (NAAMS). The results indicated that the WRF model parameters had substantial effects on the simulation of the ground wind field, high-altitude wind field, and ground humidity field. In contrast, the parameters had no significant effect on the simulation of the ground temperature field, high-altitude temperature field, and high-altitude humidity field. The combination of the SLAB land surface process scheme and Dudhia shortwave radiation scheme with four boundary layer schemes, namely YSU, ACM2, BouLac, and MRF, could well-simulate the trends of winter surface wind, temperature, and humidity fields in Sichuan basin. The simulation results were analyzed by combining the statistical parameters of high-altitude wind, temperature, and humidity. The group 1 parameter scheme was applicable to simulate the meteorological field of Dazhou. Group 13 and Group 17 parameters were applicable to simulate the meteorological fields in Chengdu during the day and night, respectively. The correlation between CALPUFF simulation and monitoring value was better than that for AERMOD. CALPUFF was more accurate than AERMOD when referring to the monitoring data from NAAMS No.3. In addition, the simulation quality of CALPUFF was slightly better than that of AERMOD with reference to data from NAAMS No.2. Using air pollutant monitoring data from NAAMS as a reference, the simulated results of CALPUFF on NOx and PM10 were improved compared to AERMOD at all four stations. Data from the Q-Q diagram indicated that the simulated results of CALPUFF on SO2, NOx, and PM10 were closer to the monitored values compared to those of AERMOD.

The structural characteristics of coal at the molecular level are important for its efficient use. Bituminous coal from the Baozigou Coal Mine is investigated, using elemental analysis, C-13 nuclear magnetic resonance, X-ray photoelectron spectroscopy, and Fourier transform infrared. The molecular structure was determined. The aromatic compounds of bituminous coal molecules are primarily two- and three-ring structures, and the aliphatic structures are primarily in the form of methyl, ethyl side chains, and naphthenic hydrocarbons. The ratio of aromatic bridge carbon to peripheral carbon in the molecular structure is 0.279. Oxygen atoms in the form of carbonyl, phenolic hydroxyl and C-O, and nitrogen atoms in pyrroles. Thus, the average structure model of bituminous coal macro-molecules was constructed; the molecular formula was C169H128O10N2S, and the molecular weight was 2378. The aromatic structural units in the macromolecular structure of coal include four naphthalenes, three anthracenes, two tetracenes, and heteroatoms in the form of three carbonyl groups, one phenolic hydroxyl group, one pyrrole, and one pyridine. The structure optimization and annealing kinetic simulation of a single macromolecular structure model were performed. Chemical bonds such as bridge bonds and aliphatic bonds were found to be twisted, and pi-pi interactions between the aromatic sheets in the molecule produced adjacent aromatic sheets. This arrangement tends to be approximately parallel, and the total energy decreases from 6713.401 to 2667.595 kJ/mol, among which the bond stretching energy and van der Waals energy dominate. We used 20 bituminous coal macromolecular models to construct aggregated structural models. After optimization by molecular dynamics simulation, the macromolecules were constrained by the surrounding molecules, and the sheet-like aromatic carbon structures that were originally approximately parallel were distorted. The macromolecular structure model of bituminous coal constructed in this study provides a theoretical model basis for the optimal surfactant.

Source apportionment offers an efficient way to identify emission sources and the contributions to air pollution. It helps to deepen our understanding of the air pollution formation process and develop productive environmental policies. Accurate PM2.5 source apportionment is more essential for small-scale local air pollution control. An integrated source apportionment approach was built by combining chemical mass balance (CMB) model and the Community Multiscale Air Quality modelling system (CMAQ) model to complement individual model and apportion PM2.5 pollution into more elaborate emission sources categories. The CMAQ source apportionment results of corresponding PM2.5 precursors were applied to assign secondary components while that of PM2.5 were applied to assign non-local sources as the basic constrains. An island city with typical secondary components in PM2.5 pollution was chosen. The results showed the dominant source impacts of non-local sources ranged from 31.07% in summer to 49.60% in winter. Compared to individual model, the integrated source apportionment approach preserved the accuracy of CMB modelling for primary sources, simultaneously apportioned the secondary components to the primary sources and abstracted non-local sources from primary sources, which acquired more elaborate results. The results further helped develop more efficient air quality control policies.

北京市北运河流域属于典型缺水型城市纳污河流,沉积物释放的氮磷污染物已成为阻碍水环境质量持续改善的主要因素.利用自制环形水槽,对不同流速下沉积物中氮磷的动态释放规律进行研究,结果表明,静态条件下,沉积物中氨氮平均释放速率1136 mg/(m2·d),磷酸盐平均释放速率为145 mg/(m2·d),在流速0.05 m/s的缓流水体中,氨氮平均释放速率为1408 mg/(m2·d),而磷酸盐平均释放速率为125 mg/(m2·d).流速增加会显著促进氮素的硝化作用,使水体中氨氮浓度降低,硝酸盐氮浓度上升.同时,流速增加导致水体中颗粒物含量增加,促进磷吸附行为,水体中磷酸盐浓度下降.

120 main industrial installations were screened based on the emissions inventory of 2016 in Cangzhou City, and the air pollution effect of PM2.5, PM10, SO2, NO2, sulfates, nitrates, and secondary organic aerosol (SOA) was simulated for 2017 autumn-winter season for different levels of pollution using the CALPUFF model after code recompilation. The results showed that the ratios of the modelled and measured concentrations of PM2.5, PM10, SO2, and NO2 were 3.3%, 5.7%, 5.6%, and 2.9%, respectively. The areas most affected by pollution from primary PM10 were the southwest and southeast part of Cangzhou, while sulfate, nitrate, and SOA pollution mainly affected the southeast part. The proportion of SOA in the PM2.5 was around 27.3%, and rose to 29.0% during heavily polluted periods. The aerosols of alkenes, tolune, xylene, and PAH in PM2.5 accouted for 12.1%, 6.0%, 7.0%, and 2.2% of the total aerosols respectively. The result of the simulation of individual enterprises showed that their total contribution to PM2.5 during heavily polluted periods was 3.02 μg·m-3, accounting for 50% of the requirements in the "Three-year Plan" for Cangzhou City (6.00 μg·m-3). The top 5 contributors were 1 Petrochemical industry in Cangzhou (0.41 μg·m-3), 2 Carbon Co. Ltd. (0.29 μg·m-3), 3 Petrochemical industry in Juhai (0.26 μg·m-3), 4 Fertilizer Company (0.23 μg·m-3), 5 Dahua Co. Ltd. (0.19 μg·m-3). These industrial installations were mainly located in Xinhua District, Cangxian, and Bohai New District. This research can provide a scientific ground for production restrictions and limitations and emissions reduction of each industry during heavily polluted periods.

The processes affecting photochemical reactions and regional transport of ozone and its precursors in ambient air are very complicated. In this study, statistical analysis of the spatial and temporal distributions of ozone pollution in Zhoushan was carried out based on monitoring data from state monitoring stations in Zhoushan in 2014. Specifically, ozone formation was simulated by CMAQ (the community multiscale air quality) model, and the source contribution rate was calculated using the Integrated Source Apportionment Method (ISAM) source tracking algorithm. The results showed that ozone pollution was more severe in spring and autumn than in summer and winter, and the highest ozone concentrations mostly appeared during 13:00-15:00 in the afternoon. Putuo Station had the highest ozone concentration while Lincheng Station, located in the downtown area of the city, had the lowest ozone concentration. The overall average ozone concentration was not high; however, peak concentrations that exceeded the standards usually occurred, which occurs most often in May. Local ozone formation in Zhoushan City is controlled by the VOC concentration, and source tracking results showed that non-local sources accounted for 69.46% of the total contribution. Among local emission sources, fuel burning boiler sources, industry process sources, on-road mobile sources, and non-road mobile sources made similar contributions to ozone formation. Moreover, they showed significant characteristics of a port city. The contribution rates from shipping sources, petrochemical sources, and storage and transportation sources were 4.45%, 1.01%, and 1.80%, respectively. In conclusion, control of the ozone pollution in Zhoushan City should be based on simultaneous reduction and coordinated prevention involving multiple sources (VOCs as the main one) both locally and in surrounding areas.

防空反导作战指控系统是构建防空反导一体化网络化体系的核心,建模仿真是研究该系统的有效方法,建立的模型是否真实可靠是研究成败的关键.在分析国内外对复杂仿真系统特别是作战仿真系统的VV&A的基础上,根据防空反导作战指控进程及其模型的特点,从需求定义、概念模型、数学模型、仿真模型4个方面对防空反导作战指控模型进行校核验证及评估的思路分析.这对防空反导作战指控系统的研究发展具有重大意义.

针对煤气化废水现有处理工艺存在的污染物去除效果差、运行成本高等问题,文章提出了短程反硝化耦合厌氧氨氧化的处理工艺.将部分原水和经硝化阶段处理的原水按一定比例混合后进入短程反硝化阶段,充分利用原水中的COD作为短程反硝化碳源获得富含氨氮和亚硝氮的出水,保证了后续厌氧氨氧化自养脱氮过程能够正常进行.通过控制反应器温度在15～25℃、pH在8.0～8.5和少量有机碳源投加的措施实现了对短程反硝化过程的稳定控制,亚硝氮积累率高达85.7％.该实验最终出水总氮去除率可达87.0％,出水COD低予28.0 mg/L,氨氮低于4.8 mg/L,证明了短程反硝化耦合厌氧氨氧化工艺的可行性和高效性.同时,该工艺曝气能耗低、有机碳源和碱度消耗少,为厌氧氨氧化技术的应用提供了新的思路.

为更好地应对大功率区外来电对电网调度和安全稳定运行的影响,在分析了江苏电网区外来电现状的基础上,从发用电平衡面临新的压力、省内电源调节压力增大和发电利用小时数偏低等方面研究了内外电源协调运行面临的主要问题,提出了调节义务分摊机制和辅助服务补偿机制等内外电源协调运行机制.

The success of the emission reduction measures undertaken by authorities in the Asia-Pacific Economic Cooperation summit 2014 demonstrated that the Beijing-Tianjin-Hebei air quality can be improved by introducing integrated emission reduction measures. This paper combines observation data, emission reduction measures, and air quality simulations that were applied before, during, and after the emission control measure implement to analyze the chemical composition change and relationship between emissions and concentrations of pollutants in region. The 24-h PM2.5 samples were collected in the city Beijing, Shijiazhuang, and Tangshan during the period of 20 October to 25 November, 2014. The total PM2.5 mass was measured. PM2.5 samples were used for the analysis of inorganic elements, selected ions, and organic carbon (OC) and element carbon (EC). PM2.5 concentrations during the emission control period were decreased. Total PM2.5 concentrations were reduced by 54, 26, and 39 % when compared to non-emission control period in Beijing, Shijiazhuang, and Tangshan. The average element concentrations were reduced significantly by 75 % in Beijing, 37 % in Shijiazhuang, and 36 % in Tangshan. After the Asia-Pacific Economic Cooperation (APEC) conference, the average element concentration increased. At both cities, the concentration secondary water-soluble ions, primary carbon, and element carbon were reduced. However, the concentration of secondary carbon species increased in Beijing due to photochemical oxidants change. More stringent control of regional emissions will be needed for significant reductions of fine particulate pollution in the region to continue to improve air quality.

基于MIKE11模型构建了北运河干流（北京段）一维河流水动力、水质模型。以2010年为基准年,综合考虑"十二五"期间人口增长、经济发展及农业规模和布局情况,设置3套减排方案。选择北京市榆林庄断面为主控监测断面,以氨氮低于5mg/L、COD低于40mg/L为水质控制目标,开展不同减排措施效果评估。结果表明,污水处理厂提标改造是改善北运河流域（北京段）水质的最有效手段,能使榆林庄断面COD和氨氮相比2010年分别下降27.2%、60.6%,COD达到水质控制目标。氨氮减排难度较大,除了实施污水处理厂提标改造外,应同步提高综合排放标准,使氨氮排放相对2010年下降73.5%,达到水质控制目标。同时,还应加强对城市暴雨径流污染的控制,以有效降低前汛期水体污染物峰值浓度。

污染排放信息是环境决策的重要依据.分析了北京市水环境质量的现状,基于最新源排放清单,解析北京市当前主控污染物COD、氨氮排放的结构特征和空间特征,以期为北京市开展基于流域综合治理的水污染控制和水环境管理提供依据.按照工业源、农业源、生活源和集中处理设施的环境统计口径,2013年,COD、氨氮的排放构成分别为2.7％、37.1％、35.0％、25.3％和1.5％、20.1％、54.8％、23.6％.其中,农业源中畜禽养殖排放是主要来源,COD、氨氮总排放分别占农业源总排放量的94.7％和87.0％.在北京市五大水系中,北运河流域排放量最大,COD、氨氮排放量分别占全市总排放量的53.3％和57.4％.为改善北京市水环境质量,建议从加快污水处理厂提标改造、推动面源污染治理、加强水利联通、合理规划城市规模布局等4个方面入手.

The paper has introduced the mechanism, technique process, process control and practical effect of combined biological method, namely"Biological washing+bio-trickling filtration", in the treatment of odor pollution of sewage plant of a petrochemical enterprise. It also analyzed the factors influencing the performance of the biological treatment facilities. After practicing, the results indicate that combined biological process can produce a relatively ideal purification effect of odor for petrochemical enterprise in odor treatment of sewage plant with hydrogen sulfide treatment efficiency reaching up to 98%and Non Methane Total Hydrocarbon processing efficiency reaching up to 94%. The process takes advantage in simple operation, low cost and no secondary pollution.

为了研究京津冀地区典型城市PM2.5及其碳组分的污染特征和来源,选取北京和唐山具有代表性的5个监测点于2012年7月3日至30日进行了PM2.5样品采集.分析研究了PM2.5、有机碳(OC)和元素碳(EC)的质量浓度及变化特征,采用OC/EC最小比值法估算了二次有机碳(SOC)的质量浓度,并使用因子分析法解析了碳组分来源.结果表明:采样期间北京市PM2.5、OC和EC质量浓度分别为76.2±38.5 μg/m3、7.0±2.2 μg/m3和3.0±1.4μg/m3,均低于唐山的97.7±38.8 μg/m3、11.7±6.3μg/m3和7.0±5.0 μg/m3;北京灰霾天气PM2.5、OC和EC浓度分别为非霾天气的2.0、1.2和1.8倍,唐山相应为1.4、1.5和1.6倍;北京和唐山SOC质量浓度分别为3.0μg/m3和5.1 μg/m3,分别占OC质量浓度的42.9％和43.6％;北京和唐山PM2.5中碳组分主要来源于燃煤和机动车尾气,其贡献量均超过75％,因此要进一步加强清洁能源替代、控制机动车保有量的增长及提高车用油质量.

简述了炼油装置区恶臭污染源的主要分布、恶臭气体组成和排放规律,介绍了恶臭治理的基本方法.通过治理实例,重点分析了目前常用的吸收法、燃烧法、生物法和吸附法等恶臭治理技术的优势和相对不足,并对恶臭治理应用技术方案的选择提出建议.

Polycyclic aromatic hydrocarbons (PAHs) produced by coke oven are with strong toxicity and carcinogenicity. Taken typical coke oven of iron and steel enterprises as the case study, the dispersion and migration of 13 kinds of PAHs emitted from coke oven were analyzed using AERMOD dispersion model, the carcinogenic and non-carcinogenic risks at the receptors within the modeling domain were evaluated using BREEZE Risk Analyst and the Human Health Risk Assessment Protocol for Hazardous Waste Combustion (HHRAP) was followed, the health risks caused by PAHs emission from coke oven were quantitatively evaluated. The results indicated that attention should be paid to the non-carcinogenic risk of naphthalene emission (the maximum value was 0.97). The carcinogenic risks of each single pollutant were all below 1.0E-06, while the maximum value of total carcinogenic risk was 2.65E-06, which may have some influence on the health of local residents.