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Quantifying the impacts of emissions and meteorology on the interannual variations of air pollutants in major Chinese cities from 2015 to 2021

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Science China Earth Sciences 2023年第8期66卷 1725-1737页

作者： qili dai Tianjiao dai Linlu HOU Linxuan LI Xiaohui BI Yufen ZHANG Yinchang FENG State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control College of Environmental Science and EngineeringNankai UniversityTianjin 300350China China Meteorological Administration-Nankai University Cooperative Laboratory for Atmospheric Environment-Health Research Tianjin 300350China

Air pollutant concentration is a function of emission rates and meteorology.To accurately evaluate the effect of control measures,the meteorological covariate must be corrected from the observations.This study quantified the impacts of emission abatement and meteorological condition on the interannual variations of SO_(2),NO_(2),CO,O_(3),PM_(10) and PM_(2.5) concentrations in 31 major Chinese cities using an optimized machine learning-based meteorological normalization technique.Overall,the annual average concentrations of SO_(2),NO_(2),CO,PM_(10)and PM_(2.5)were reduced by 86%,51%,99%,86% and 88%from 2015 to 2020,respectively,in the studied cities,attributable to their emission reductions.However,the concentration of O_(3) was found with no significant decrease with the reduction of precursors.Emission abatement notably improved air quality between 2015 and 2018.Such a decline in emissions tended to progressively slow down since 2018.Overall,the meteorological conditions in 2016–2017 and 2018–2019 were unfavorable for a better air quality,while it became favorable in 2020–2021.Specifically,emission abatement in 2021 further lowered the concentrations of SO_(2),NO_(2),CO,and PM_(2.5),while the emission of PM_(10) increased.And changes in precursors emissions worsened O_(3) air quality.To meet the demand of improving air quality,more aggressive abatement measures need to be formulated to synergistically reduce NOx,volatile organic compounds,and coarse particles.

关键词： Air pollution Air quality Machine learning Meteorology Emissions Policy evaluation

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Impacts of meteorology and precursor emission change on O_(3) variation in Tianjin, China from 2015 to 2021

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Journal of Environmental Sciences 2023年第4期126卷 506-516页

作者： Jing Ding qili dai Wenyan Fan Miaomiao Lu Yufen Zhang Suqin Han Yinchang Feng Tianjin Environmental Meteorological Center Qi xiangtai roadTianjin 300074China State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control College of Environmental Science and EngineeringNankai UniversityTianjin 300350China CMA-NKU Cooperative Laboratory for Atmospheric Environment-Health Research Tianjin 300074China

Deterioration of surface ozone (O_(3)) pollution in Northern China over the past few years received much attention.For many cities,it is still under debate whether the trend of surface O_(3)variation is driven by meteorology or the change in precursors emissions.In this work,a time series decomposition method (Seasonal-Trend decomposition procedure based on Loess (STL)) and random forest (RF) algorithm were utilized to quantify the meteorological impacts on the recorded O_(3)trend and identify the key meteorological factors affecting O_(3)pollution in Tianjin,the biggest coastal port city in Northern China.After “removing” the meteorological fluctuations from the observed O_(3)time series,we found that variation of O_(3)in Tianjin was largely driven by the changes in precursors emissions.The meteorology was unfavorable for O_(3)pollution in period of 2015-2016,and turned out to be favorable during 2017-2021.Specifically,meteorology contributed 9.3μg/m^(3)O_(3)(13%) in 2019,together with the increase in precursors emissions,making 2019 to be the worst year of O_(3)pollution since 2015.Since then,the favorable effects of meteorology on O_(3)pollution tended to be weaker.Temperature was the most important factor affecting O_(3)level,followed by air humidity in O_(3)pollution season.In the midday of summer days,O_(3)pollution frequently exceeded the standard level (>160μg/m^(3)) at a combined condition with relative humidity in 40%-50%and temperature>31℃.Both the temperature and the dryness of the atmosphere need to be subtly considered for summer O_(3)forecasting.

关键词： Ozone Meteorological conditions Time series decomposition Random forest Meteorological adjustment

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Impact of meteorological condition changes on air quality and particulate chemical composition during the COVID-19 lockdown

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Journal of Environmental Sciences 2021年第11期33卷 45-56页

作者： Jing Ding qili dai Yafei Li Suqin Han Yufen Zhang Yinchang Feng Tianjin Environmental Meteorological Center Tianjin 300074China State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control College of Environmental Science and EngineeringNankai UniversityTianjin 300350China CMA-NKU Cooperative Laboratory for Atmospheric Environment-Health Research Tianjin 300074China

Stringent quarantine measures during the Coronavirus Disease 2019(COVID-19)lockdown period(January 23,2020 to March 15,2020)have resulted in a distinct decrease in anthropogenic source emissions in North China Plain compared to the paralleled period of 2019.Particularly,22.7%decrease in NO_(2)and 3.0%increase of O_(3)was observed in Tianjin,nonlinear relationship between O_(3)generation and NO_(2)implied that synergetic control of NOx and VOCs is needed.Deteriorating meteorological condition during the COVID-19 lockdown obscured the actual PM2.5 reduction.Fireworks transport in 2020 Spring Festival(SF)triggered regional haze pollution.PM2.5 during the COVID-19 lockdown only reduced by 5.6%in Tianjin.Here we used the dispersion coefficient to normalize the measured PM2.5(DN-PM2.5),aiming to eliminate the adverse meteorological impact and roughly estimate the actual PM2.5 reduction,which reduced by 17.7%during the COVID-19 lockdown.In terms of PM2.5 chemical composition,significant NO_(3)−increase was observed during the COVID-19 lockdown.However,as a tracer of atmospheric oxidation capacity,odd oxygen(Ox=NO_(2)+O_(3))was observed to reduce during the COVID-19 lockdown,whereas relative humidity(RH),specific humidity and aerosol liquid water content(ALWC)were observed with noticeable enhancement.Nitrogen oxidation rate(NOR)was observed to increase at higher specific humidity and ALWC,especially in the haze episode occurred during 2020SF,high air humidity and obvious nitrate generation was observed.Anomalously enhanced air humidity may response for the nitrate increase during the COVID-19 lockdown period.

关键词： COVID-19 lockdown Air quality Meteorological condition Air humidity Aerosol chemistry

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Size distribution and chemical characteristics of particles from crop residue open burning in North China

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Journal of Environmental Sciences 2021年第11期33卷 66-76页

作者： Tingkun Li qili dai Xiaohui Bi Jianhui Wu Yufen Zhang Yinchang Feng State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control College of Environmental Science and EngineeringNankai UniversityTianjin300350China.

Crop residue open burning is an important emission source of ambient particles in China.This study analyzed the particle emission characteristics of crop residue open burning through combustion experiments with a novel open combustion simulation device using three typical crop straws in north China(corn,wheat,and rice).Particle samples size ranging from 0.006–9.890μm were collected by an Electrical Low Pressure Impactor plus,a high size-resolution instrument capable of dividing particles into 14 size stages.The size distributions of organic carbon(OC),elemental carbon(EC),water-soluble ions,and elements were analyzed,and source chemical profiles were constructed for PM0.1,PM1,PM2.5,and PM10.The number concentration of particles was concentrated in the Aiken nuclei mode(0.006–0.054μm),accounting for 75%of the total number,whereas the mass concentration was concentrated in the accumulation mode(0.054–0.949μm),accounting for 85.43%of the mass loading.OC,EC,Cl−,and K(include total K and water-soluble K)were the major chemical components of the particles,whose mass percentage distributions differed from those of other components.These fivemain components exhibited a bell-shaped size distribution in the 0.006–9.890μm range,whereas the other components exhibited a U-shaped distribution.Among the chemical profiles for PM0.1–PM10,OC was the most important component at 10–30%,followed by EC at 2%–8%.The proportions of K^(+),Cl^(−),and K varied substantially in different experimental groups,ranging from 0–15%,and K+and Cl−were significantly correlated(r=0.878,α=0.000).

关键词： Crop residue Open burning Size distribution Source profile Electrical Low Pressure Impactor plus(ELPI+)

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Insight into the critical factors determining the particle number concentrations during summer at a megacity in China

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Journal of Environmental Sciences 2019年第1期31卷 169-180页

作者： Baoshuang Liu Xiaohui Bi Jiaying Zhang Jie Yuan Zhimei Xiao qili dai Yinchang Feng Yufen Zhang State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control & Center for Urban Transport Emission Research College of Environmental Science and EngineeringNankai University Tianjin Environmental Monitoring Center

To identify the critical factors impacting the number concentration of particles with the aerodynamic diameters less than 2.5 μm(PNC_(2.5)), the continuous measurement of PNC_(2.5),chemical components in PM_(2.5), gaseous pollutants and meteorological conditions were conducted at an urban site in Tianjin in June 2015. Results indicated that the average PNC_(2.5) was 2839 ± 2430 d N/dlog Dp 1/cm^3 during the campaign. Compared to other meteorological parameters, the relative humidity(RH) had the strongest relationship with PNC_(2.5), with a Pearson's correlation coefficient of 0.53, and RH larger than 30% influenced strongly PNC_(2.5).The important influence of secondary reactions on PNC_(2.5) was inferred due to higher correlation coefficients between PNC_(2.5) and SO_4^(2-), NO_3^-, NH_4^+(r = 0.78–0.89; p < 0.01) and between PNC_(2.5) and ratios that represent the conversion of nitrogen and sulfur oxides to particulate matter(r = 0.42–0.49; p < 0.01). Under specific RH conditions, there were even stronger correlations between PNC_(2.5) and NO_3^-, SO_4^(2-), NH_4^+, while those between PNC_(2.5) and EC, OC were relatively weak, especially when RH exceeded 50%. Principal component analysis(PCA) and Pearson's correlation analysis indicated that secondary sources, vehicle emission and coal combustion might be major contributors to PNC_(2.5). Backward trajectory and potential source contribution function(PSCF) analysis suggested that the transport of air masses originated from these regions around Tianjin(Liaoning, Hebei, Shandong and Jiangsu) influenced critically PNC_(2.5). The north of Jiangsu, the west of Shandong, and the east of Hebei were distinguished as major potential source-areas of PNC_(2.5) by PSCF model.

关键词： Particle number concentration Correlation analysis Emission sources PSCF

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我国典型区域二氧化碳和细颗粒物精细化协同减排路径

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科学通报 2024年第10期69卷 1373-1384页

作者：赵焕许博徐晗王振宇高洁黄俊波戴启立冯银厂史国良南开大学环境科学与工程学院国家环境保护城市空气颗粒物污染防治重点实验室天津300350 南开大学环境科学与工程学院中国气象局-南开大学大气环境与健康研究联合实验室天津300350

随着碳达峰、碳中和目标的提出,我国环境保护进入减污降碳协同治理新阶段.目前研究主要探寻空气质量政策或气候政策对二氧化碳和细颗粒物的减排效益.而从二氧化碳和细颗粒物排放终端能源消费重点行业、主要能源以及主导因素等角度出发,... 详细信息

随着碳达峰、碳中和目标的提出,我国环境保护进入减污降碳协同治理新阶段.目前研究主要探寻空气质量政策或气候政策对二氧化碳和细颗粒物的减排效益.而从二氧化碳和细颗粒物排放终端能源消费重点行业、主要能源以及主导因素等角度出发,来探究我国典型区域协同减排路径精细化方法的研究则鲜见报道.本研究基于2000~2020年我国京津冀、长江三角洲、珠江三角洲典型区域能源消耗数据,首先探明了3个典型区域二氧化碳和细颗粒物终端能源消费的重点排放行业均为工业;并进一步甄别了终端能源消费重点行业中PM_(2.5)排放主要能源为煤类能源,而CO_(2)排放主要能源由煤类能源逐渐转向煤、气类能源,但煤类仍为主导地位;随后使用因素分解模型解析了能源强度、技术进步等主导因素对单位国内生产总值的二氧化碳以及细颗粒物的影响效应;最终利用能源-环境核算预测模型,基于上述研究识别的终端能源消费重点行业、主要能源以及主导因素进行情景分析,旨在判断典型区域不同情景下碳达峰情况,进而寻找协同减排最优路径.结果发现,“技术进步”因素在前期减排效果最好;“能效提升”因素的减排效果在长时期碳污协同减排将起到关键作用,表明未来针对工业排放等终端能源消费重点行业,关注煤、气类等主要能源,采取能效提升、技术进步等手段措施,能够对减污降碳协同增效目标的实现产生最佳收益.希望本研究能为我国典型区域二氧化碳和细颗粒物合理化、精细化协同减排和管控提供科学证据.

关键词：二氧化碳细颗粒物 LEAP模型情景分析协同控制精细化

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2001—2020年天津市大气污染特征的演变与防治历程

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环境科学研究 2022年第4期35卷 945-955页

作者：王雪涵张文慧毕晓辉戴启立吴建会肖致美张裕芬冯银厂南开大学环境科学与工程学院中国气象局-南开大学大气环境与健康研究联合实验室国家环境保护城市空气颗粒物污染防治重点实验室天津300350 天津市生态环境监测中心天津300191

近20年来,随着经济社会的快速发展与污染防治工作的不断深入,我国大气污染特征发生显著变化,特别是京津冀及周边城市空气质量显著改善,大气污染特征与来源构成出现结构性变化,十分有必要对这20年来大气污染的演变历程加以梳理总结.本文... 详细信息

近20年来,随着经济社会的快速发展与污染防治工作的不断深入,我国大气污染特征发生显著变化,特别是京津冀及周边城市空气质量显著改善,大气污染特征与来源构成出现结构性变化,十分有必要对这20年来大气污染的演变历程加以梳理总结.本文选取北方特大工业城市——天津市为研究对象,基于20年来连续监测数据与相关统计学方法,结合天津市历年大气颗粒物源解析结果,总结了该地区大气污染特征的演变过程.结果表明:天津市环境空气质量在过去20年出现明显好转,大气污染类型由燃煤扬尘为主的一次混合型逐渐演变为O_(3)与PM_(2.5)为代表的二次复合型.历年源解析结果表明,天津市2020年秋冬季二次硫酸盐贡献率比2011年同期减少了74.1%,燃煤贡献率则下降了31.6%;扬尘和机动车尾气尘贡献率分别从2011年的17.7%和19.9%降至2020年的15.8%和18.2%;而2020年二次硝酸盐贡献率比2011年增长了63.3%.过去20年天津市重大污染防治措施的有效性分析表明,能源结构调整和“双散”替代使煤炭消耗量减少,PM_(2.5)浓度下降与煤炭消耗量减少呈显著相关[偏相关系数(R)=0.879,P<0.05];粗颗粒(PM_(2.5~10))浓度下降与绿化覆盖率增加呈显著相关[偏相关系数(R)=-0.859,P<0.05];大规模取缔中小燃煤锅炉及脱硫除尘等重大举措的实施,使得SO_(2)浓度显著下降[秩相关系数(r_(s))=-0.9586,P<0.05].研究显示,近20年来大气污染防治减排措施的实施使得天津市环境空气质量明显改善,未来要紧密结合国家“双碳”战略,进一步优化产业与能源结构,实现空气质量的持续改善.

关键词：天津市大气污染污染特征防治历程

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六类餐饮源排放PM2.5化学成分谱

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环境科学研究 2021年第1期34卷 71-78页

作者：李林璇程渊杜鑫戴启立吴建会毕晓辉冯银厂南开大学环境科学与工程学院国家环境保护城市空气颗粒物污染防治重点实验室天津300071 中国气象局-南开大学大气环境与健康研究联合实验室天津300350

大气颗粒物源成分谱可以表征源排放颗粒物的理化特征,为受体模型开展来源解析研究提供基础数据.餐饮油烟排放是室内外环境大气污染的来源之一,当前餐饮源排放PM2.5的化学成分谱仍然缺乏.该研究分别在成都市、武汉市和天津市采集了29组6... 详细信息

大气颗粒物源成分谱可以表征源排放颗粒物的理化特征,为受体模型开展来源解析研究提供基础数据.餐饮油烟排放是室内外环境大气污染的来源之一,当前餐饮源排放PM2.5的化学成分谱仍然缺乏.该研究分别在成都市、武汉市和天津市采集了29组6种餐饮源(居民烹饪、火锅店、烧烤店、职工食堂、中餐馆、商场综合餐饮)排放的PM2.5样品,分析无机元素、离子、碳、多环芳烃(PAHs)等化学组分,并构建了餐饮源排放颗粒物化学成分谱.结果表明:①餐饮源排放PM2.5化学成分中的主要组分为OC(有机碳)、EC(元素碳)、Ca、Al、Fe、NH 4+、SO 4^2-、NO 3^-、Na^+、K^+、Mg ^2+和Cl^-,其中w(OC)最高,为41.67%~57.91%.②餐饮源排放PM2.5的PAHs中,3环和4环占比较高,其中芴(Flu)、菲(Phe)、荧蒽(Fla)、芘(Pyr)的质量分数相对其他物质较高.研究显示:餐饮源排放PM2.5中OC EC约为15.99~67.61,在一定程度上可以用来表征餐饮源排放;Fla(Fla+Pyr)和InP(InP+BghiP)多集中在0.45~0.55之间,或可作为标识餐饮源的特征比值.

关键词：餐饮源 PM2.5 化学组成源成分谱多环芳烃(PAHs)

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腹腔镜巨大食管裂孔疝修补改良术的临床研究

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中华消化内镜杂志 2015年第11期32卷 729-733页

作者：孙向宇秦鸣放吴瑜赵宏志戴其利天津市南开医院微创外科天津300100

目的探讨腹腔镜食管裂孔疝修补改良术治疗巨大食管裂孔疝的安全性及有效性。方法2010年6月至2014年5月，采用腹腔镜疝囊完全分离、关闭食管裂孔至正常、放置双面复合补片、联合胃底折叠术的改良技术治疗49例巨大食管裂孔疝。观察手术时... 详细信息

目的探讨腹腔镜食管裂孔疝修补改良术治疗巨大食管裂孔疝的安全性及有效性。方法2010年6月至2014年5月，采用腹腔镜疝囊完全分离、关闭食管裂孔至正常、放置双面复合补片、联合胃底折叠术的改良技术治疗49例巨大食管裂孔疝。观察手术时间、住院时间、术后并发症，术后上消化道造影和症状改善状况随访。结果手术时间为（103．6±31．7）min（88—173min），术后住院时间（4．2±1．8）d（3～12d）。4例出现并发症，肺感染伴胸腔积液1例，呼吸衰竭1例，吞咽困难2例，并发症发生率8．2％（4／49）。无中转及死亡病例。49例术后平均随访（28．3±12．7）个月（6～50个月），术后主要症状改善显著，上消化道造影无食管裂孔疝复发。结论腹腔镜食管裂孔疝修补改良术治疗巨大食管裂孔疝是安全、有效的。

关键词：疝食管裂孔腹腔镜胃底折叠补片

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DX-DN数字对讲系统ⅡC级防爆用户话站的研制

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电子技术（上海） 2014年第1期41卷 64-66,57页

作者：谈莹青戴力李雪强武钢通信公司

DX．DN数字对讲系统现有的防爆用户话站是IIB级，虽然可以适用于冶金行业绝大多数的爆炸性危险场所，但是不能在存在氢气、乙炔等IIC级爆炸性气体的场所使用。文章从结构设计和电路设计两个方面详细说明了该话站的具体设计方案，并给出... 详细信息

DX．DN数字对讲系统现有的防爆用户话站是IIB级，虽然可以适用于冶金行业绝大多数的爆炸性危险场所，但是不能在存在氢气、乙炔等IIC级爆炸性气体的场所使用。文章从结构设计和电路设计两个方面详细说明了该话站的具体设计方案，并给出了关键的设计参数和生产工艺要求。经南阳国家防爆电气产品质量监督检测中心进行检测证明，该话站在保证频响、非线性失真、输出功率、失真度等电性能指标，并实现单呼、组呼、广播呼叫等功能的基础之上，防爆性能完全符合国家标准规定。该话站取得国家电气设备防爆合格证，防爆标志为ExdibIICT6，适用于工厂存在IIA、IIB、IIc类，T1～T6组可燃性气体、蒸汽与空气混合形成的爆炸危险1区或2区场所使用。

关键词：数字对讲冶金防爆电气

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