Reviews of emission of biogenic volatile organic compounds (BVOCs) in Asia

Biogenic volatile organic compounds(BVOCs) in the atmosphere play important roles in the formation of ground-level ozone and secondary organic aerosol(SOA) in global scale and also in regional scale under some condition due to their large amount and relatively higher reactivity.In places with high plant cover in the tropics and in China where air pollution is serious,the effect of BVOCs on ozone and secondary organic aerosols is strong.The present research aims to provide a comprehensive review ...     

耕作土壤中多氯代有机污染物的含量与分布特征-以珠江三角洲部分地区为例

采用超声波提取,气相色谱分析法,调查了珠江三角洲部分地区几种耕作土壤和珠江主要支流,西南涌上、中、下游沿岸耕作土壤中的多氯代有机污染物的含量研究结果表明,供试土壤中多氯代有机污染物（CBs、BHCs和DDTs）均有不同程度检出,其含量大小因所处区域、土壤类型和土地利用方式的不同而异;西南涌上、中、下游耕层土壤中多氯代有机污染物的含量呈递减趋势,主要受灌溉水质的影响;污染物在土壤剖面中的分布特征与其亲脂性相关,脂溶性强的污染物的含量随剖面深度的加深而减小,脂溶性弱的污染物的含量随剖面深度加深而升高;供试土壤中部分污染物的同系物含量之间存在一定的相关性。     

珠江三角洲天然源VOCs排放量估算及时空分布特征

利用实际观测的气象数据和基于遥感图像解译的土地利用现状和植被资料,运用GloBEIS模型,对珠江三角洲2006年度天然源VOCs排放总量进行了估算.结果表明,该区天然源VOCs的年度排放总量达29.6万t,其中异戊二烯7.30万t,占24.7%,单萜10.2万t,占34.4%.其排放量具有夏季高冬季低的典型特征,夏季占全年排放量的40.5%,冬季占11.1%.其空间特征与土地利用和植被分布密切相关,天然源VOCs排放主要集中在城镇化程度较低和林区较密集的区域.此外,对天然源VOCs排放估算过程中可能的不确定性来源进行了讨论.     

珠江三角洲地区铺装道路扬尘排放因子与排放清单研究

对珠江三角洲地区不同等级道路共采集了65个道路扬尘样品,并调研了道路的车流量、车辆构成和道路长度等有关活动水平数据,采用美国环保署推荐的AP-42方法估算了该地区不同等级道路扬尘排放因子和排放量,并分析了道路扬尘排放的时空特征与不确定性范围.结果表明:高速公路、一级、二级、三级和四级道路尘负荷分别为1.05 g·m^-2、0.99 g·m^-2、1.30 g·m^-2、1.35 g·m^-2和1.45 g·m^-2;不同等级道路扬尘总悬浮颗粒物(Total Suspended Particulate,TSP)、PM₁₀和PM_2.5的平均排放因子分别为8.32 g·VKT^-1 (Grams per Vehicle Kilometer Traveled)、1.60 g·VKT^-1和0.39 g·VKT^-1,对应的排放量分别为2755.1×10³ t、528.8×10³ t和127.9×10³ t,其定量不确定性范围分别为-91.7%~175.1%、-91.6%~178.9%及-91.5%~176.5%.     

Ambient volatile organic compounds at a receptor site in the Pearl River Delta region: Variations, source apportionment and effects on ozone formation

We present the continuously measurements of volatile organic compounds（VOCs） at a receptor site（Wan Qing Sha, WQS） in the Pearl River Delta（PRD） region from September to November of 2017. The average mixing ratios of total VOCs（TVOCs） was 36.3 ± 27.9 ppbv with the dominant contribution from alkanes（55.5%）, followed by aromatics（33.3%）. The diurnal variation of TVOCs showed a strong photochemical consumption during daytime,resulting in the formation of ozone（O₃）. Five VOC sources were ...     

珠三角典型地区大气污染时段VOCs特征及化学反应活性

于2016年在广东大气超级监测站,开展4个季节的VOCs、O₃和PM_2.5长时间、高分辨率的连续观测,共获得2142组有效数据,并利用OH消耗速率(LOH)、臭氧生成潜势(OFP)和二次有机气溶胶生成潜势(SOAFP)3种评价方法以及HYSPLIT模型,分析珠三角典型地区大气污染时段VOCs特征及化学反应活性.结果表明,PM_2.5高值时段,除异戊二烯外,其余各种VOCs的平均浓度水平高于O₃高值时段.3种情境中,VOCs化学反应活性由强到弱依次为PM_2.5高值时段、观测期间、O₃高值时段.在O₃高值时段,来自珠三角东部地区气团中VOCs的浓度水平最高,而来自珠江西岸气团中VOCs的LOH和OFP最高,其次为来自珠三角东部的气团,这说明在珠江西岸和珠三角东部地区有大量的强化学反应活性污染物排放.来自北方内陆地区气团中苯系物占比较高,其SOAFP最高.在PM_2.5高值时段,来自南部海洋气团中VOCs的混合比、LOH、...     

珠江三角洲印刷行业VOCs组分排放清单及关键活性组分

根据珠江三角洲地区印刷行业活动数据和不锈钢罐采样-气质联用技术,获取了印刷工艺VOCs成分谱,建立了该地区2010年印刷行业VOCs组分排放清单,研究了不同工艺排放的臭氧生成潜势. 结果表明:该地区2010年印刷行业VOCs排放总量达8591.26t,深圳、东莞、佛山排放量较大.凹印是印刷行业主要VOCs排放工艺,排放量达5762.01t;平印和凸印次之,分别为1954.01和37.82t.不同工艺排放的VOCs组分差异较大,平印工艺排放的VOCs成分中异丙醇含量最多(306.58t),其次为正庚烷(115.87t);苯和甲苯是凸印工艺排放的VOCs成分中含量最大的2种化合物,分别达5.58和4.83t;乙酸乙酯是凹印工艺排放的VOCs成分中的首要化合物,达2482.85t.凸印工艺排放的VOCs单位浓度臭氧潜势最大,达1.30μg/m3,平印和凹印较小,分别为0.89和0.72μg/m3,各工艺排放的含氧有机物对臭氧生成潜势的贡献均为最大.      

Compositions and sources of organic acids in fine particles (PM2.5) over the Pearl River Delta region, south China

Organic acids as important constituents of organic aerosols not only influence the aerosols' hygroscopic property, but also enhance the formation of new particles and secondary organic aerosols. This study reported organic acids including C14–C32fatty acids, C4–C9dicarboxylic acids and aromatic acids in PM2.5collected during winter 2009 at six typical urban, suburban and rural sites in the Pearl River Delta region. Averaged concentrations of C14–C32fatty acids, aromatic acids and C4– C9 dicarboxylic acids were 157, 72.5 and 50.7 ng/m3, respectively. They totally accounted for 1.7% of measured organic carbon. C20–C32fatty acids mainly deriving from higher plant wax showed the highest concentration at the upwind rural site with more vegetation around, while C14–C18fatty acids were more abundant at urban and suburban sites, and dicarboxylic acids and aromatic acids except 1,4-phthalic acid peaked at the downwind rural site. Succinic and azelaic acid were the most abundant among C4–C9dicarboxylic acids, and 1,2-phthalic and 1,4-phthalic acid were dominant aromatic acids. Dicarboxylic acids and aromatic acids exhibited significant mutual correlations except for 1,4-phthalic acid, which was probably primarily emitted from combustion of solid wastes containing polyethylene terephthalate plastics. Spatial patterns and correlations with typical source tracers suggested that C14–C32fatty acids were mainly primary while dicarboxylic and aromatic acids were largely secondary. Principal component analysis resolved six sources including biomass burning, natural higher plant wax, two mixed anthropogenic and two secondary sources; further multiple linear regression revealed their contributions to individual organic acids. It turned out that more than 70% of C14–C18fatty acids were attributed to anthropogenic sources, about 50%–85% of the C20–C32fatty acids were attributed to natural sources, 80%–95% of dicarboxylic acids and 1,2-phthalic acid were secondary in contrast with that 81% of 1,4-phthalic acid was primary.     

珠江三角洲海岸背景区大气VOCs污染特征与来源

挥发性有机物（volatile organic compounds,VOCs）是臭氧（O₃）污染防控备受关注的重要前体物.本研究基于2019年8月~2020年7月在杨梅坑生态环境监测站开展的VOCs连续在线观测数据,对珠江三角洲海岸背景区大气VOCs的时间变化规律、物种组成进行了分析,并利用受体模型和后向轨迹模型分析了VOCs的来源特征.结果表明,珠江三角洲海岸背景区人为源VOCs年平均浓度（体积分数）为9.30×10^-9,呈秋、冬季高,夏季低的特点.与一般城市和背景点的日变化规律不同,珠江三角洲海岸背景区人为源VOCs峰值主要出现在10：00~11：00;凌晨和15：00之后浓度会维持在较低水平.乙烯、丙烯、甲苯、异戊烷、异戊二烯、间/对-二甲苯、正丁烷和乙炔是影响珠江三角洲海岸背景区VOCs化学组成的关键物种.影响珠江三角洲海岸背景区的气团主要来源：省内短距离气团（25%）、海洋气团（27%）、沿海气团（31%）和省外内陆气团（17%）,其中海洋气团影响下VOCs平均浓度水平最低,主要受到船舶排放与老化VOCs混合源、汽油挥发与汽车排放源影响;其他气团影响下平均较海洋气团影响下VOCs浓度升高了70.1%~148.8%,以工业源、LNG与LPG挥发源、石化源这三类源的传输影响较为突出.     

Biogenic volatile organic compound analyses by PTR-TOF-MS: Calibration, humidity effect and reduced electric field dependency

Green leaf volatiles(GLVs) emitted by plants after stress or damage induction are a major part of biogenic volatile organic compounds(BVOCs). Proton transfer reaction time-of-flight mass spectrometry(PTR-TOF-MS) is a high-resolution and sensitive technique for in situ GLV analyses, while its performance is dramatically influenced by humidity, electric field,etc. In this study the influence of gas humidity and the effect of reduced field(E/N) were examined in addition to measuring calibration curves for the GLVs. Calibration curves measured for seven of the GLVs in dry air were linear, with sensitivities ranging from 5 to10 ncps/ppbv(normalized counts per second/parts per billion by volume). The sensitivities for most GLV analyses were found to increase by between 20% and 35% when the humidity of the sample gas was raised from 0% to 70% relative humidity(RH) at 21°C, with the exception of(E)-2-hexenol. Product ion branching ratios were also affected by humidity,with the relative abundance of the protonated molecular ions and higher mass fragment ions increasing with humidity. The effect of reduced field(E/N) on the fragmentation of GLVs was examined in the drift tube of the PTR-TOF-MS. The structurally similar GLVs are acutely susceptible to fragmentation following ionization and the fragmentation patterns are highly dependent on E/N. Overall the measured fragmentation patterns contain sufficient information to permit at least partial separation and identification of the isomeric GLVs by looking at differences in their fragmentation patterns at high and low E/N.     

Biogenic volatile organic compound analyses by PTR-TOF-MS: Calibration,humidity effect and reduced electric field dependency

Green leaf volatiles (GLVs) emitted by plants after stress or damage induction are a major part of biogenic volatile organic compounds (BVOCs). Proton transfer reaction time-of-flight mass spectrometry (PTR-TOF-MS) is a high-resolution and sensitive technique for in situ GLV analyses, while its performance is dramatically influenced by humidity, electric field, etc. In this study the influence of gas humidity and the effect of reduced field (E/N) were examined in addition to measuring calibration curves for the GLVs. Calibration curves measured for seven of the GLVs in dry air were linear, with sensitivities ranging from 5 to 10 ncps/ppbv (normalized counts per second/parts per billion by volume). The sensitivities for most GLV analyses were found to increase by between 20% and 35% when the humidity of the sample gas was raised from 0% to 70% relative humidity (RH) at 21°C, with the exception of (E)-2-hexenol. Product ion branching ratios were also affected by humidity, with the relative abundance of the protonated molecular ions and higher mass fragment ions increasing with humidity. The effect of reduced field (E/N) on the fragmentation of GLVs was examined in the drift tube of the PTR-TOF-MS. The structurally similar GLVs are acutely susceptible to fragmentation following ionization and the fragmentation patterns are highly dependent on E/N. Overall the measured fragmentation patterns contain sufficient information to permit at least partial separation and identification of the isomeric GLVs by looking at differences in their fragmentation patterns at high and low E/N.     

珠江三角洲秋季臭氧干沉降特征的数值模拟

利用区域化学传输模式WRF-Chem对2014年10月珠江三角洲臭氧干沉降特征进行模拟,结果表明：臭氧干沉降通量呈现明显的时空分布差异,日间平均沉降通量[0.68μg/（m²·s）]明显大于夜间[0.21μg/（m²·s）];同时,珠江三角洲城区的臭氧沉降通量及日较差均比周边植被覆盖区小.受NO_x和VOCs等前体物以及各气象要素场的综合影响,臭氧浓度日变化具有明显的单峰型分布特征,在14：00~15：00达到峰值,秋季臭氧浓度高值区位于珠江三角洲主要排放源下风向区域的广佛交界、江门及中山东部等地区;臭氧的干沉降速率也具有明显的时空变化特征：从07：00~08：00的0.27cm/s开始迅速增大,10：00~16：00基本保持在0.60cm/s左右,17：00开始平缓减小至午夜的0.21cm/s左右;干沉降速率的变化主要受空气动力学阻抗R_a、粘性副层阻抗R_b以及表面阻抗R_c影响,研究表明夜间的干沉降速率主要受R_a影响,而日间R_c起主要作用.这3种阻抗分别受大气稳定度、摩擦速度和下垫面土地利用类型影响,在珠江三角洲区域亦表现出明显的时空变化特征.     

春节与疫情管控期间珠三角VOCs的组成和来源变化

挥发性有机物(VOCs)是对流层中臭氧(O3)生成过程的关键前体物,是O3与PM2.5协同治理的重要管控对象.基于2020年1月1日～2月29日珠江三角洲(珠三角)4个站点的在线VOCs观测数据,分析了春节与疫情管控期间珠三角地区VOCs组分、活性、臭氧生成潜势和来源的变化.结果表明,春节与疫情管控期间珠三角地区φ(V...     

珠江三角洲地区冬季硫、氮干沉降的来源解析

采用WRF-CMAQ模式对珠江三角洲地区2015年1月进行数值模拟,结合CMAQ的集成源解析方法ISAM对S、N及其干沉降的来源贡献进行分析.结果表明：珠江三角洲地区S、N干沉降量高值主要分布在广佛交界处以及珠江口附近,其逐日变化趋势主要受质量浓度变化影响,但在部分时间段受干沉降速率的影响亦相当显著.珠江三角洲区域内排放源对于S干沉降的平均贡献占比为36.2%,与其质量浓度区域内贡献占比相当,SO₂干沉降速率增加以及背景风场变弱会使区域内贡献占比增加;区域内源对于N干沉降的平均贡献占比为32.4%,远小于其质量浓度区域内贡献占比,当NO₂质量浓度减少,使得HNO₃的质量浓度和干沉降量减少时,区域内贡献占比增加.对于珠江三角洲典型城市,广州S干沉降的本地贡献为27.7%,N为14.2%;江门S干沉降的本地贡献为9.6%,N为8.8%.2个城市对比而言,广州受本地的影响较江门显著,江门受其上风方向广州和佛山两市输送的影响显著,但当背景风场减弱时,江门本地贡献会有明显增加.     

珠江三角洲地区冬季硫、氮干沉降的来源解析

采用WRF-CMAQ模式对珠江三角洲地区2015年1月进行数值模拟,结合CMAQ的集成源解析方法ISAM对S、N及其干沉降的来源贡献进行分析.结果表明：珠江三角洲地区S、N干沉降量高值主要分布在广佛交界处以及珠江口附近,其逐日变化趋势主要受质量浓度变化影响,但在部分时间段受干沉降速率的影响亦相当显著.珠江三角洲区域内排放源对于S干沉降的平均贡献占比为36.2%,与其质量浓度区域内贡献占比相当,SO₂干沉降速率增加以及背景风场变弱会使区域内贡献占比增加;区域内源对于N干沉降的平均贡献占比为32.4%,远小于其质量浓度区域内贡献占比,当NO₂质量浓度减少,使得HNO₃的质量浓度和干沉降量减少时,区域内贡献占比增加.对于珠江三角洲典型城市,广州S干沉降的本地贡献为27.7%,N为14.2%;江门S干沉降的本地贡献为9.6%,N为8.8%.2个城市对比而言,广州受本地的影响较江门显著,江门受其上风方向广州和佛山两市输送的影响显著,但当背景风场减弱时,江门本地贡献会有明显增加.     

珠江三角洲大气排放源清单与时空分配模型建立

收集整理2012年珠江三角洲地区(简称“珠江三角洲”)各种大气人为源及天然源基础活动数据,以排放因子法“自下而上”为主计算多污染物排放量,并建立本地化污染物空间分配方案及基于行业排污特征的时间分配谱,构建了具备时空分布属性的区域性网格化大气源排放清单.清单结果显示,2012年珠江三角洲SO2、NOx、CO、PM10、PM2.5、VOCs和NH3排放总量分别为55.2万t、102.9万t、349.2万t、95.2万t、38.5万t、153.9万t和17.7万t. 固定燃烧源是珠江三角洲SO2和NOx的最大排放贡献源,其中电厂和锅炉分别贡献了35.0%和41.8%的SO2排放,以及28.2%和16.2%的NOx排放;VOCs的最大贡献源是过程源,其中家具制造、石油精炼、油气码头排放量总和占比为52.4%;扬尘源是颗粒物的主要来源之一,对PM2.5的排放贡献达42.3%;NH3的主要排放源为畜禽养殖和化肥施用源,两者排放量占比分别为50.7%和26.8%.珠江三角洲大气污染物空间与时间分布结果显示,高排放污染源主要集中于“东莞-广州-佛山”一带,呈半环带状结构分布;白天时段(9:00~20:00)的排放强度明显高于夜晚时段(21:00~次日8:00);夏秋季节(4~10月)的排放强度略高于冬春季节(11月~次年3月).     

Air pollution characteristics and their relationship with emissions and meteorology in the Yangtze River Delta region during 2014–2016

With rapid economic growth and urbanization, the Yangtze River Delta(YRD) region in China has experienced serious air pollution challenges. In this study, we analyzed the air pollution characteristics and their relationship with emissions and meteorology in the YRD region during 2014–2016. In recent years, the concentrations of all air pollutants, except O_3,decreased. Spatially, the PM_(2.5), PM_(10), SO_2, and CO concentrations were higher in the northern YRD region, and NO_2 and O_3 were higher in the central YRD region. Based on the number of non-attainment days(i.e., days with air quality index greater than 100), PM_(2.5) was the largest contributor to air pollution in the YRD region, followed by O_3, PM_(10), and NO_2.However, particulate matter pollution has declined gradually, while O_3 pollution worsened.Meteorological conditions mainly influenced day-to-day variations in pollutant concentrations. PM_(2.5) concentration was inversely related to wind speed, while O_3 concentration was positively correlated with temperature and negatively correlated with relative humidity.The air quality improvement in recent years was mainly attributed to emission reductions.During 2014–2016, PM_(2.5), PM_(10), SO_2, NO_x, CO, NH_3, and volatile organic compound(VOC)emissions in the YRD region were reduced by 26.3%, 29.2%, 32.4%, 8.1%, 15.9%, 4.5%, and0.3%, respectively. Regional transport also contributed to the air pollution. During regional haze periods, pollutants from North China and East China aggravated the pollution in the YRD region. Our findings suggest that emission reduction and regional joint prevention and control helped to improve the air quality in the YRD region.     

前体物排放变化对珠江三角洲地区秋季臭氧污染演变的影响研究

自2013年以来,珠三角地区SO₂、NO_x及颗粒物等污染物浓度逐渐下降,但臭氧污染日渐凸显.作为二次污染物,臭氧污染演变受到排放与气象条件共同影响.而评估本地前体物人为排放变化、外部传输和气象变化对臭氧污染演变的影响,并识别臭氧污染长期演变趋势的重要驱动因素,是开展区域臭氧污染防控的关键基础.因此,本文采用WRF-SMOKE-CMAQ模拟平台,以2006—2017年广东省和中国大气污染物排放趋势清单为输入清单,以2014年的气象数据为基准年气象场,通过设置不同案例,结合观测数据,定量评估本地、外部排放变化和气象变化对珠三角秋季O₃污染长期演变趋势的影响.结果表明：在2006—2017年期间,整个珠三角9—10月臭氧日最大8 h(MDA8)浓度上升主要由人为排放变化主导,平均每年贡献0.7μg·m^-3,而气象条件总体上抑制了2006—2017年期间珠三角秋季臭氧MDA8浓度的增长,使得秋季臭氧MDA8浓度上升速率下降为0.2μg·m^-3·a^-1;人为排放变化...     

2006～2012年珠江三角洲地区O_3污染对人群健康的影响

通过检索国内流行病学研究成果,Meta分析得到综合的暴露-反应系数后,利用粤港珠江三角洲区域空气监控网络监测的O3浓度,基于相对危险度模型对2006~2012年珠江三角洲地区归因于O3污染的人群健康影响进行评估.Meta分析结果表明,O3浓度每升高10μg/m3,非意外死亡率?心血管疾病死亡率和呼吸系统疾病死亡率分别上升0.45%(95%置信区间CI:0.40%~0.50%)?0.70%(95%CI:0.57%~0.86%)和0.64%(95%CI:0.47%~0.86%).人群健康影响评估表明,由于暴露人口和O3浓度的增加,珠江三角洲地区归因O3污染的死亡人数呈上升趋势,2012年归因死亡人数约为2006年的3倍,其中O3浓度的增加对归因死亡增量的贡献达2/3以上;2006~2012年区域年均归因的非意外死亡?心血管疾病死亡和呼吸系统疾病死亡分别为3982(95%CI:3543~4420)?1894(95%CI:1546~2319)和1128(95%CI:830~1508)人.对评估模型的敏感性试验表明选择不同的参数,评估结果有较大的偏差,因此在以后相关研究工作中需要深化参数适用性的探讨.     

2013-2017年珠江三角洲主要大气污染控制措施减排效果评估

自2013年《大气污染防治行动计划》发布以来,珠江三角洲(PRD)地区实施了严格的大气污染防控政策,在全国率先实现PM2.5浓度连续3年达标,然而,已实施的控制措施对污染物的减排效果尚不清楚,因此,本研究通过广泛收集2013-2017年珠三角地区大气污染源活动水平数据与控制措施,建立2013-2017年实际控制与未控制...