臭氧浓度升高对植物源挥发性有机化合物(BVOCs)影响的研究进展

伴随地表臭氧(O_3)浓度在全球范围内的普遍上升,针对植物源挥发性有机化合物(biogenic volatile organic compounds,BVOCs)与地表O_3之间复杂的交互作用,本文综述了O_3浓度升高对BVOCs影响方面取得的研究进展,并对未来研究提出了展望.研究进展主要包括BVOCs应对单因子O_3胁迫的影响因素(如BVOCs种类,植物功能类型,植物O_3敏感性及O_3胁迫程度),以及O_3分别与升温/二氧化碳(CO_2)/干旱/氮(N)沉降等因子复合对BVOCs释放的影响.虽然O_3胁迫不影响BVOCs释放的研究最多,但O_3胁迫的降低作用在异戊二烯和落叶树种的研究中更突出,增加的结果更多地出现在单萜(MTs)、常绿植物和急性熏蒸的实验里. O_3与升温/N沉降复合处理增加MTs释放,O_3与CO_2复合处理降低了异戊二烯释放.鉴于研究样本的稀缺,建议加强该领域研究,同时要考虑短期和长期处理、个体和生态系统水平研究的差异;加强以O_3为主的多因子复合及生物与非生物多重胁迫对BVOCs影响的研究,以便更好评估陆地生态系统BVOCs对当前及未来O_3污染情景的响应,为今后大气污染防治提供有价值的理论支撑.     

常州市人为源挥发性有机物排放清单

对常州市VOCs人为源进行系统划分,运用国内外排放因子研究成果及常州市各排放源调研结果,采用排放因子法建立了2017年常州市分类型、分辖区(市)的人为源VOCs排放清单。结果表明,2017年常州市人为源VOCs排放总量约为9. 662×10~4t,其中化石燃料燃烧源、工业过程源、移动源、非工业溶剂使用源、油品储运源、生物质燃烧源、固废污水处理源和餐饮源排放分别占排放总量的1. 9%,47. 2%,9. 0%,27. 6%,9. 4%,2. 6%,0. 4%和1. 9%。工业过程源中黑色(有色)金属冶炼及压延加工业、非金属矿物制品业、化学原料和化学品制造业、机械装备制造业、交通设备制造业、纺织业是重点行业;武进区、溧阳市、新北区3个工业发达的区域VOCs排放量明显高于常州其他几个辖区,占全市总排放量的71%;各辖区(市)的重点排放源存在差异,其中武进区、溧阳市、新北区以工业过程源为主,金坛区、天宁区、钟楼区以非工业溶剂使用源为主。     

快速液相色谱-串联质谱法测定环境空气中的全氟化合物

不同研究报道的空气中离子型全氟化合物(PFCs)的分析方法各不相同,本文的目的在于对比和优化不同分析条件。通过对比不同流动相(甲醇和乙腈)、不同色谱柱(C8和C18)、不同梯度洗脱条件下目标化合物的分离效果,确定了以甲醇为流动相、C18色谱柱为分离柱和最佳梯度淋洗液分离的仪器分析条件。比较了甲醇和正已烷/丙酮混合溶剂萃取气相(PUF)和颗粒相(GFF)样品的效果,确定以甲醇为萃取溶剂。建立了空气中PFCs的LC-MS/MS优化分析方法,方法线性范围在0.1~50 ng·m L~(-1)之间,PUF与GFF样品方法检出限分别为0.02~0.35 pg·m~(-3)和0.02~0.26 pg·m~(-3)。同时将方法用于大气实际样品分析。     

Characterization of an urban landfill soil by using physicochemical analysis and solid phase microextraction (SPME)—GC/MS

We have aimed at characterizing top soil samples taken in-situ from five different locations of the unregulated dumping site in Eskişehir/Turkey for a period of six months. The study is the first attempt in the city and in Turkey, regarding particularly the SPME (Solid Phase Microextraction Technique) analysis method utilized. A comprehensive research has been conducted to produce critical soil data to be used for indicating current risks as well as the urgency of rehabilitating the site and establishing a sanitary landfill in the site. Conventional physicochemical analytical methods and SPME technique were used to analyze the samples. Physicochemical analyses were performed for determining the pH, total dried matter, volatile matter, total nitrogen, phosphorus, macro elements and heavy metals. Meteorological data were also recorded for the same period. SPSS.10.0 statistical program was used to determine the correlation between meteorological data and physicochemical analysis results. Mean values were used in the correlation analyses. These data indicated that the air temperature and precipitation have significant effects on soil characteristics. SPME, coupled with GC/MS, was used to identify eighty six volatile and semi-volatile organic compounds contained in soil samples. The samples were extracted by headspace SPME with heating (δHS-SPME). SPME analyses were conducted using a commercially available polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber having a film thickness of 65 μm (Supelco) as a capture medium. The experimentally optimized headspace sampling conditions were arranged (15 min. at 50^˚C) before a 30 min. sampling period.     

鹫峰国家森林公园大气中VOCs的组成与特点

采用TCT-GC/MS方法对鹫峰国家森林公园大气中挥发性有机物(VOCs)的组成进行分析,共检测到175种挥发性有机化合物,主要成分包括烷烃类、芳香烃类、酯类、酸类、醛类、酮类和萜烯类等七类,平均相对含量分别为48.11%,15.67%,17.28%,3.13%,3.17%,1.36%和1.45%;活动区中检测到的挥发性有机化合物种类最多,缓冲区次之,非活动区最少,这与每个区中人类活动的频率相一致.同时分析了大气中的VOCs的时空分布特点.     

Reductive Dechlorination of Tetrachloroethylene by Soil Sulfate-Reducing Microbes under Various Electron Donor Conditions

Biotransformation of tetrachloroethylene (PCE) by soil sulfate-reducing bacteria was investigated using acetate, lactate and methanol as electron donors. Results show that the effectiveness of biotransformation of PCE by soil sulfate-reducing bacterial is dependent upon the type of electron donor used.     

两种常见植物净化室内空气的效果

为探讨家居植物对甲醛的吸收能力和对改善室内空气质量的效果,将库拉索芦荟（Aloevera）和虎尾兰（Sansevieria trifasciata）两种植物放置于相对封闭的环境中,进行16d的甲醛暴露实验。结果表明,虎尾兰的甲醛耐受性高于库拉索芦荟,在整个实验过程中都保持良好的生长状态,具有持续的甲醛去除能力（去除率达...     

重量法研究非离子表面活性剂对典型挥发性有机污染物的增溶作用

采用重量法研究了典型非离子表面活性剂（Tween-20、Tween-40、Tween-60、Tween-80）对以甲苯为代表的挥发性有机污染物（VOCs）的增溶作用.通过计算甲苯在初始和平衡状态的质量变化,确定甲苯在表面活性剂中的增溶量,比较了重量法与传统紫外分光光度法的测定结果,并计算分析4种表面活性剂增溶作用下甲苯...     

Effects of design parameters on performance and cost analysis of combined ultraviolet-biofilter systems treating gaseous chlorobenzene based on mathematical modeling

A conceptual mathematical model was used to evaluate the design parameters of a combined ultraviolet (UV)-biofilter system, and perform a cost analysis. Results showed that the UV light source strength and the gas residence times in the UV system (UVRT) and biofilter (EBRT) had positive effects on the overall chlorobenzene removal efficiency of the system. High ratio of UVRT to EBRT improved the removal efficiency, suggesting that the UV system has a greater effect on the overall performance of the system compared with the biofilter. Analysis of the capital and operating costs showed that the capital costs of the standalone biofilter system were much higher than those of the standalone UV system. However, the biofilter operating costs were lower than those of the UV system. The operating costs of the combined UV-biofilter system increased with increasing UVRT/EBRT ratio, whereas its capital costs decreased.     

Indoor carbonyl compounds in an academic building in Beijing, China: concentrations and influencing factors

Carbonyl compounds in indoor air are of great concern for their adverse health effects. Between February and May, 2009, concentrations of 13 carbonyl compounds were measured in an academic building in Beijing, China. Total concentration of the detected carbonyls ranged from 20.7 to 189.1 μg·m^-3, and among them acetone and formaldehyde were the most abundant, with mean concentrations of 26.4 and 22.6 μg·m^-3, respectively. Average indoor concentrations of other carbonyls were below 10 μg·m^-3. Principal component analysis identified a combined effect of common indoor carbonyl sources and ventilation on indoor carbonyl levels. Diurnal variations of the carbonyl compounds were investigated in one office room, and carbonyl concentrations tended to be lower in the daytime than at night, due to enhanced ventilation. Average concentrations of carbonyl compounds in the office room were generally higher in early May than in late February, indicating the influence of temperature. Carbonyl source emission rates from both the room and human occupants were estimated during two lectures, based on one-compartment mass balance model. The influence of human occupants on indoor carbonyl concentrations varies with environmental conditions, and may become significant in the case of a large human occupancy.