关于我国环境空气与废气标准体系有关问题的探讨

环境空气与废气标准体系是实施环境空气与废气管理的基础之一,没有完善的环境空气与废气标准体系,就无法对环境空气质量与大气污染物排放情况进行科学、规范、准确的监测和评价。文章分析了我国环境空气与废气标准体系的现状,指出了其中存在的问题,并提出了切实可行的改进措施和建议。通过这些措施和建议的实施,将进一步完善我国环境空气与废气标准体系,促进基层环境保护工作的发展。     

2013-2017年石化和化学工业重点耗能产品单位综合能耗下降目标

本刊讯：2014年中央层面治理雾霾的决心很大．利用特高压输电方式解决雾霾问题,预计特高压建设有望加快推进。国务院总理李克强近日提出．在抓紧完善大气治理现有政策的基础上．     

Seasonal and diurnal variations of atmospheric peroxyacetyl nitrate, peroxypropionyl nitrate, and carbon tetrachloride in Beijing

Atmospheric peroxyacetyl nitrate(PAN), peroxypropionyl nitrate(PPN), and carbon tetrachloride(CCl4) were measured from September 2010 to August 2011 in Beijing. PAN exhibited low values from mid-autumn to early spring(October to March) with monthly average concentrations ranging from 0.28 to 0.73 ppbV, and increased from early spring to summer(March to August), ranging from 1.37–3.79 ppbV. The monthly variation of PPN was similar to PAN, with low values(below detection limit to 0.18 ppbV) from mid-autumn to early spring, and a monthly maximum in September(1.14 ppbV). The monthly variation of CCl4was tightly related to the variation of temperature, exhibiting a minimum in winter(69.3 pptV) and a maximum of 180.6 pptV in summer. Due to weak solar intensity and short duration, PAN and O3showed no distinct diurnal patterns from morning to night during winter, whereas for other seasons, they both exhibited maximal values in the late afternoon(ca. 15:00 to 16:00 local time) and minimal values during early morning and midnight. Good linear correlations between PAN and PPN were found in autumn(R = 0.91), spring(R = 0.94), and summer(R = 0.81), with slopes of 0.130, 0.222, and 0.133, respectively, suggesting that anthropogenic hydrocarbons dominated the photochemical formation of PANs in Beijing. Positive correlation between PAN and O3 in summer with the low slopes( O3 / PAN) ranging from 9.92 to 18.0 indicated serious air pollution in Beijing, and strong negative correlation in winter reflected strong O3consumption by NO titration and less thermal decompositin of PAN.     

Characteristics of atmospheric particles and heavy metals in winter in Chang-Zhu-Tan city clusters, China

To understand the pollution characteristics of atmospheric particles and heavy metals in winter in Chang-Zhu-Tan city clusters, China, total suspended particulate(TSP) and PM10samples were collected in cities of Changsha, Zhuzhou and Xiangtan from December 2011 to January 2012, and heavy metals of Cd, Pb, Cr, and As were analyzed. It shows that the average TSP concentration in Changsha, Zhuzhou and Xiangtan were(183 ± 73),(201 ± 84) and(190 ± 66) μg/m3respectively, and the average PM10 were(171 ± 82),(178 ± 65) and(179 ± 55) μg/m3respectively. The lowest TSP and PM10concentrations occurred at the background Shaping site of Changsha. The average ratio of ρ(PM10)/ρ(TSP) was 91.9%, ranging from 81.3% to 98.9%. Concerning heavy metals, in TSP samples, the concentration of Cr, As, Cd and Pb were 28.8–56.5, 18.1–76.3, 3.9–26.1 and 148.0–460.9 ng/m3, respectively, while in PM10samples, were 16.4–42.1, 15.5–67.9, 3.3–22.2 and 127.9–389.3 ng/m3, respectively. The enrichment factor of Cd was the highest, followed by Pb and As, while that of Cr was the lowest.     

Reduction and characterization of bioaerosols in a wastewater treatment station via ventilation

Bioaerosols from wastewater treatment processes are a significant subgroup of atmospheric aerosols. In the present study,airborne microorganisms generated from a wastewater treatment station(WWTS) that uses an oxidation ditch process were diminished by ventilation.Conventional sampling and detection methods combined with cloning/sequencing techniques were applied to determine the groups,concentrations,size distributions,and species diversity of airborne microorganisms before and after ventilation. There were 3021 ± 537 CFU/m3 of airborne bacteria and 926 ± 132 CFU/m3 of airborne fungi present in the WWTS bioaerosol.Results showed that the ventilation reduced airborne microorganisms significantly compared to the air in the WWTS. Over 60% of airborne bacteria and airborne fungi could be reduced after4 hr of air exchange. The highest removal(92.1% for airborne bacteria and 89.1% for fungi) was achieved for 0.65–1.1 μm sized particles. The bioaerosol particles over 4.7 μm were also reduced effectively. Large particles tended to be lost by gravitational settling and small particles were generally carried away,which led to the relatively easy reduction of bioaerosol particles0.65–1.1 μm and over 4.7 μm in size. An obvious variation occurred in the structure of the bacterial communities when ventilation was applied to control the airborne microorganisms in enclosed spaces.     

城市应急重气扩散模型在JU2003扩散试验中的模拟验证

发展了一个能够考虑昼夜大气稳定度差异的城市应急重气扩散模型——SLAB_URBAN模型,利用该模型对美国Oklahoma City Joint Urban 2003(JU2003)城市扩散试验进行了模拟,主要关注下风方向不同观测距离的Cmaxu/Q值,并将模型模拟出的Cmaxu/Q值与JU2003试验观测的Cmaxu/Q值进行了对比验证。结果表明:SLAB_URBAN模型能够模拟出昼夜不同稳定度条件下城市重气扩散在下风方向浓度的分布状况;SLAB_URBAN模型的统计误差分析显示其模拟结果与观测值较一致;此外,从应急反应和安全角度考虑,SLAB_URBAN模型也符合实际工作的需求。     

西安城区大气中多氯联苯季节变化及来源解析

为了解西安城区大气中多氯联苯(Polychlorinated biphenyls,PCBs)的浓度水平、季节变化特征及来源,于2012年夏季、冬季分别对西安市城区大气进行每周1次的主动采样,共获得22对大气样品(气态和颗粒态).结果表明,西安城区大气中∑64PCBs的浓度为76.21~338.77pg·m-3,平均浓度为183.85 pg·m-3,且主要存在于气态样品中.组成上主要以低氯代PCBs为主,其中,三氯和四氯代PCBs占总浓度的59.64%~91.39%.气态样品中,夏季、冬季PCBs的平均浓度分别为201.68、151.11 pg·m-3;颗粒态样品中,冬季PCBs平均浓度是夏季的6.65倍.通过主成分分析法对西安城区大气中PCBs的来源进行解析,发现主成分1的方差贡献率为36.06%,主要为来自我国生产的变压器油源;主成分2的方差贡献率为20.29%,可能来自于油漆的使用.     

云南大气降水中δ18O与气象要素及水汽来源之间的关系

根据云南昆明、腾冲、蒙自三个地区在2009 年1 月至2011 年12 月3 a 间收集的大气降水以及相关气象要素资料,结合欧洲中期数值预报中心以及NCEP/NCAR提供的再分析资料,研究了天气尺度下三个地区大气降水中δ¹⁸O与降水量、温度、水汽压等气象要素之间的关系,并分析了δ¹⁸O与高空各气压层（800、700、500、300 hPa）风速的相关关系。结果表明：在天气尺度下,三个地区大气降水中δ¹⁸O与降水量、温度、水汽压均存在显著的负相关,表明三个地区大气降水中δ¹⁸O的变化具有显著的降水量效应、反温度效应以及湿度效应;同时,高空各气压层风速与δ¹⁸O之间存在正相关关系,表明高空风速也是影响大气降水中δ¹⁸O变化的一个重要因素。通过拉格朗日后向轨迹模型HYSPLIT 4.8 追踪三个地区水汽输送轨迹发现,三个地区大气降水的水汽来源基本一致,表明三地处在同一条水汽通道上。在湿季降水期间（5-9 月）,水汽主要来源于孟加拉湾、阿拉伯海以及南海等海域,降水中δ¹⁸O偏低;而在干季降水期间（10 月-翌年4月）,水汽主要来源于西风带携带的内陆水汽以及局地水汽再循环,降水中δ¹⁸O偏高。     

利用FLEXPART模式反演中国区域SF6排放量

六氟化硫(SF_6)是一种长寿命卤代温室气体,被列为《京都议定书》限排物种.随着经济高速发展,中国的SF6排放量受到世界各国的关注.采用传统的"自下而上"清单方法估算SF6排放量时,所需排放因子、活动水平数据的准确性和时效性存在较大局限.因此,本文利用拉格朗日粒子扩散模式FLEXPART,结合2009年北京上甸子区域大气本底站SF6浓度观测资料,尝试建立中国区域SF6排放量的反演方法.结果表明,初步反演的2009年中国区域SF6排放量为1.25×103(0.53×103~1.97×103)t·a-1,与文献结果相当,源排放量的不确定性从1.05×103t·a-1减小到0.72×103t·a-1.与先验源相比,反演源的相关系数从0.37提高到0.43,均方根误差减小了2.64%.     

珠江三角洲地区大气和土壤中多氯联苯分布特征研究

为了考察珠江三角洲地区大气和土壤中多氯联苯(PCBs)残留现状,于2012年在珠江三角洲地区采集了空气和土壤样品,并利用GC-MS进行PCBs分析测定。结果表明,大气中Σ24PCBs的总浓度为240~2 258 pg/m3,平均为1 243 pg/m3,且PCBs主要存在于气相中,占24种PCBs总浓度的90%以上,单体分布主要以三氯~五氯联苯为主。自2001年以来珠江三角洲地区大气中PCBs浓度有小幅波动,说明部分地区有PCBs源释放的可能。土壤中24种PCBs的总浓度为ND~20.68 ng/g,平均为3.77 ng/g。三氯联苯是土壤中PCBs的主要同类物,平均占土壤中24种PCBs总浓度的45%,其次是四氯联苯,平均占19%。部分地点低氯代PCBs比例下降,高氯代比例升高。