国外城市垃圾焚烧排放物标准比较

本文综述了国外几个发达国家及公司在城市垃圾焚烧技术中污染物排放的一些标准，可以为国内在设计城市垃圾处理厂及垃圾焚烧炉时提供有益的借鉴。     

Origins of black carbon from anthropogenic emissions and open biomass burning transported to Xishuangbanna, Southwest China

Black carbon (BC) has importance regarding aerosol composition, radiative balance, and human exposure. This study adopted a backward-trajectory approach to quantify the origins of BC from anthropogenic emissions ($\mathrm{B}{\mathrm{C}}_{\text{An}}$) and open biomass burning ($\mathrm{B}{\mathrm{C}}_{\text{BB}}$) transported to Xishuangbanna in 2017. Haze months, between haze and clean months, and clean months in Xishuangbanna were defined according to daily PM_2.5 concentrations of >75, 35–75, and <35 µg/m³, respectively. Results showed that the transport efficiency density (TED) of BC transported to Xishuangbanna was controlled by the prevailing winds in different seasons. The yearly contributions to the effective emission intensity of $\mathrm{B}{\mathrm{C}}_{\text{An}}$ and $\mathrm{B}{\mathrm{C}}_{\text{BB}}$ transported to Xishuangbanna were 52% and 48%, respectively. However, when haze occurred in Xishuangbanna, the average $\mathrm{B}{\mathrm{C}}_{\text{An}}$ and $\mathrm{B}{\mathrm{C}}_{\text{BB}}$ contributions were 23% and 77%, respectively. This suggests that open biomass burning (BB) becomes the dominant source in haze months. Myanmar, India, and Laos were the dominant source regions of BC transported to Xishuangbanna during haze months, accounting for 59%, 18%, and 13% of the total, respectively. Furthermore, India was identified as the most important source regions of $\mathrm{B}{\mathrm{C}}_{\text{An}}$ transported to Xishuangbanna in haze months, accounting for 14%. The two countries making the greatest contributions to $\mathrm{B}{\mathrm{C}}_{\text{BB}}$ transported to Xishuangbanna were Myanmar and Laos in haze months, accounting for 55% and 13%, respectively. BC emissions from Xishuangbanna had minimal effects on the results of the present study. It is suggested that open BB in Myanmar and Laos, and anthropogenic emissions in India were responsible for poor air quality in Xishuangbanna.     

喷淋对大空间喷头上方羽流特性的影响

基于经典羽流模型,通过全尺寸试验测量大空间喷头上方羽流中心线不同高度处的温度和速度,分析羽流中心线温度和速度的变化规律,并与经典羽流模型做比较,得出喷淋对大空间喷头上方羽流特性的影响。结果表明:喷淋启动前,羽流温度和速度随高度增加的变化趋势与经典羽流模型基本一致;喷淋启动后,各高度处温度显著降低,速度显著减小,温度随时间的变化趋势与喷淋压力有关,且温度和速度随高度增加的变化趋势发生明显改变。     

长江三角洲2010~2018年生物质燃烧中等挥发性有机物(IVOCs)排放清单

中等挥发性有机物（IVOCs）是一类重要的二次有机气溶胶（SOA）的前体物.其中,生物质燃烧是IVOCs的重要来源之一,但目前尚未包括在传统的排放清单中.本研究基于卫星火点排放清单（FINN）以及IVOCs/POA比例法对长三角地区2010至2018年生物质燃烧IVOCs的排放量进行估算,构建长三角地区2010～2018年基于卫星火点的生物质燃烧IVOCs排放清单,并分析其不确定性,为后续模拟长三角地区SOA的来源提供重要的基础数据.结果表明,在2010～2018年期间,长三角地区火点数整体呈现下降趋势,在过去3年（2016～2018年）火点数维持在6000次左右,较2016年之前下降了约60%.从火点数的月分布来看,火点发生最多的月份是5～8月,其次在10月有个小高峰.基于IVOCs/POA比例系数法的计算结果表明,由不同的POA/OC以及IVOCs/POA比例得到的长三角地区生物质燃烧IVOCs排放总量结果差别巨大,平均值为73.4万t（10.5～305.7万t）.基于蒙特卡罗的不确定性模拟,长三角地区生物质燃烧IVOCs排放量的不确定范围在-99%～68%之间.     

黑龙江省秸秆露天焚烧污染物排放清单及时空分布

以黑龙江省为例,采用排放因子法计算了2016年秸秆露天焚烧污染物排放清单,分析了污染物的时空分布特征.结果表明,黑龙江省秸秆露天焚烧各污染物排放量为：CO₂ 1314.09万t、CO 41.92万t、CH₄ 3.77万t、NMVOCs 8.35万t、NH₃ 0.65万t、BC 0.44万t、OC 3.13万t、SO₂ 0.50万t、NO_X 3.28万t、PM₁₀ 8.81万t、PM_2.5 10.14万t.在95%的置信区间确定了排放清单的不确定性,不确定性范围为NO_X的±86%的低值到CO的±187%的高值.通过可靠性分析推断,本文的排放清单是合理的.玉米和水稻秸秆露天焚烧对同种大气污染物的贡献高于其他作物秸秆.大气污染物排放高值区位于黑龙江省西部和东部,污染物排放的时段在全年范围内具有明显的双峰特征.秸秆露天焚烧率的下降能有效促进大气污染物的减排,且农垦地区集约化和规模化的管理模式能有效控制秸秆露天焚烧.     

Dynamics of major air pollutants from crop residue burning in mainland China, 2000–2014

Based on satellite image data and China's Statistical Yearbooks(2000 to 2014), we estimated the total mass of crop residue burned, and the proportion of residue burned in the field vs.indoors as domestic fuel. The total emissions of various pollutants from the burning of crop residue were estimated for 2000-2014 using the emission factor method. The results indicate that the total amount of crop residue and average burned mass were 8690.9 Tg and4914.6 Tg, respectively. The total amount of emitted pollutants including CO_2, CO, NOx,VOCs, PM_(2.5), OC(organic carbon), EC(element carbon) and TC(total carbon) were 4212.4–8440.9 Tg, 192.8–579.4 Tg, 4.8–19.4 Tg, 18.6–61.3 Tg, 18.8–49.7 Tg, 6.7–31.3 Tg, 2.3–4.7 Tg, and8.5–34.1 Tg, respectively. The emissions of pollutants released from crop residue burning were found to be spatially variable, with the burning of crop residue mainly occurring in Northeast, North and South China. In addition, pollutant emissions per unit area(10 km ×10 km) were mostly concentrated in the central and eastern regions of China. Emissions of CO_2, NOx, VOCs, OC and TC were mainly from rice straw burning, while burning of corn and wheat residues contributed most to emissions of CO, PM_(2.5) and EC. The increased ratio of PM_(2.5) emissions from crop residue burning to the total emitted from industry during the study period is attributed to the implementation of strict emissions management policies in Chinese industry. This study also provides baseline data for assessment of the regional atmospheric environment.     

Highly time-resolved aerosol characteristics during springtime in Weizhou Island

A single particle aerosol mass spectrometer was deployed to measure the changes of single particle species and sizes during March 2015 in Weizhou Island of the Beibu Gulf, Guangxi province, South China. In this campaign, a total of 3,100,597 particles were sized, and 25.8%particles with both positive and negative mass spectrum were collected and 24.8%characterized in combination with the ART-2 a neural network algorithm. The distribution of sized particles was mainly in from 520 to 600 nm, and the diameters ranging from 340 to1000 nm accounted for above 90%. Eight types of particles were classified: Elemental Carbon containing(EC), Organic Carbon containing(OC), EC and OC combined containing particles,Na containing particles, K containing particles(K), Levoglucosan containing particles,mineral containing particles, and Heavy Metal containing particles(HM). EC, OC and K were the major containing particles, which accounted for 84.3% in the eight types particles. The relative ratio and size distribution of the three types were EC(48.1%, 620 nm), OC(12.7%,440 nm), and K(23.5%, 600 nm), respectively. The three types of particles were a bit increasing ratios compared with those in clean periods during haze pollution periods.Combined with the back-trajectory results from the Hysplit-4 model and local pollution sources revealed that the ambient air quality on the Weizhou Island may be influenced by biomass burning in the Indochina Peninsula(biomass burning in the Indochina Peninsula)from the transportation on higher level atmospheric layer and by mainland of south China located northeast of Weizhou Island on the ground.     

春节期间燃放烟花爆竹对我国城市空气质量影响分析

对2013年、2014年我国部分城市春节期间空气质量数据进行分析,结果表明:集中燃放烟花爆竹对我国城市环境空气质量造成了严重影响,大部分城市在集中燃放日出现空气质量超标现象;燃放烟花爆竹可以导致空气中PM10、PM2.5等污染物浓度显著上升;燃放活动还可以导致PM2.5中K、Ba、Pb、Cu等元素含量明显上升;集中燃放烟花爆竹对颗粒物小时浓度值、日均值和年均值均有一定的贡献。     

非线性拉伸对甲烷-空气预混火焰燃烧特性的影响

使用定容燃烧弹与高速纹影照相系统研究了不同当量比下甲烷-空气预混气体的层流火焰燃烧特性。实验数据同时应用传统线性模型和非线性模型分析了不同当量比对球形扩展火焰的传播速率和马克斯坦长度的影响。结果显示:随着当量比的增加,层流燃烧速率先增大后减小,直到当量比为1.1时,火焰速率达到最大值。马克斯坦长度始终为正值,且随着当量比的增大而增大。在所有当量比条件下,线性和非线性方法计算的火焰速率大致相同,差值小于0.01 m/s;线性方法得到的马克斯坦长度均大于非线性模型计算的结果,并随着当量比的增大,两种方法得到的马克斯坦长度的差值更加显著。     

Grassland Bird Responses to Land Management in the Largest Remaining Tallgrass Prairie

Abstract: Extensive habitat loss and changing agricultural practices have caused widespread declines in grassland birds throughout North America. The Flint Hills of Kansas and Oklahoma—the largest remaining tallgrass prairie—is important for grassland bird conservation despite supporting a major cattle industry. In 2004 and 2005, we assessed the community, population, and demographic responses of grassland birds to the predominant management practices (grazing, burning, and haying) of the region, including grasslands restored under the Conservation Reserve Program (CRP). We targeted 3 species at the core of this avian community: the Dickcissel (Spiza americana), Grasshopper Sparrow (Ammodramus savannarum), and Eastern Meadowlark (Sturnella magna). Bird diversity was higher in native prairie hayfields and grazed pastures than CRP fields, which were dominated by Dickcissels. Although Dickcissel density was highest in CRP, their nest success was highest and nest parasitism by Brown‐headed Cowbirds (Moluthrus ater) lowest in unburned hayfields (in 2004). Conversely, Grasshopper Sparrow density was highest in grazed pastures, but their nest success was lowest in these pastures and highest in burned hayfields, where cowbird parasitism was also lowest (in 2004). Management did not influence density and nest survival of Eastern Meadowlarks, which were uniformly low across the region. Nest success was extremely low (5–12%) for all 3 species in 2005, perhaps because of a record spring drought. Although the CRP has benefited grassland birds in agricultural landscapes, these areas may have lower habitat value in the context of native prairie. Hayfields may provide beneficial habitat for some grassland birds in the Flint Hills because they are mowed later in the breeding season than elsewhere in the Midwest. Widespread grazing and annual burning have homogenized habitat—and thus grassland‐bird responses—across the Flint Hills. Diversification of management practices could increase habitat heterogeneity and enhance the conservation potential of the Flint Hills for grassland birds.