Polycyclic aromatic hydrocarbons in bulk PM2.5 and size-segregated aerosol particle samples measured in an urban environment

To analyze polycyclic aromatic hydrocarbons (PAHs) at an urban site in Seoul, South Korea, 24-hr ambient air PM_2.5 samples were collected during five intensive sampling periods between November 1998 and December 1999. To determine the PAH size distribution, 3-day size-segregated aerosol samples were also collected in December 1999. Concentrations of the 16 PAHs in the PM_2.5 particles ranged from 3.9 to 119.9 ng m⁻³ with a mean of 24.3 ng m⁻³.An exceptionally high concentration of PAHs(∼120 ng m⁻³) observed during a haze event in December 1999 was likely influenced more by diesel vehicle exhaust than by gasoline exhaust, as well as air stagnation, as evidenced by the low carbon monoxide/elemental carbon (CO/EC) ratio of 205 found in this study and results reported by previous studies. The total PAHs associated with the size-segregated particles showed unimodal distributions. Compared to the unimodal size distributions of PAHs with modal peaks at < 0.12 μm measured in highway tunnels in Los Angeles (Venkataraman and Friedlander, 1994), four- to six-ring PAHs in our study had unimodal size distributions, peaking at the larger size range of 0.28–0.53 μm, suggesting the coagulation of freshly emitted ultrafine particles during transport to the sampling site. Further, the fraction of PAHs associated with coarse particles(> 1.8 μm) increased as the molecular weight of the PAHs decreased due to volatilization of fine particles followed by condensation onto coarse particles.     

运用QSARs方法比较和预测取代苯类化合物的毒性

本文运用ＱＳＡＲｓ方法比较了惰性化合物卤代苯和次惰性化合物硝基苯类,苯胺类化合物对金鱼的急性毒性试验,鱼肝脏内控制ＡＴＰ水解的Ｎａ＾＋、Ｋ＾＋－ＡＴＰ酶不知力试验以及发光菌毒性试验。     

Simultaneous determination of p-arsanilic acid and roxarsone in feed by liquid chromatography-hydride generation online coupled with atomic fluorescence spectrometry

A novel, simple and sensitive liquid chromatography-hydride generation online coupled with atomic fluorescence spectrometry (LC-HG-AFS) method was developed for simultaneous determination of p-arsanilic acid (p-ASA) and roxarsone in feed. 20% Methanol aqueous was used as extraction reagent, after preprocessing samples by ultrasonic oscillation, then injected into the chromatography Waters symmetry shield RP18 analytical column (150mm x 4.6mm, 5 microm), finally detected by an atomic fluorescence spectrometer. The calibration curves of analyses were linear over a range of concentrations (0.2-4mg L-1 and the correlation coefficients were higher than 0.9990. The limits of detection were 0.2 mg L-1. The method has been validated by linearity, precision and recovery. p-ASA and roxarsone in feed can be successfully and simultaneously determined using the developed method without a tedious pretreatment procedure.     

人工泳池水质的模糊综合评判及分析

用模糊数学方法 ,处理人工泳池水质监测数据 ,综合评判泳池水质状况 ,分析水质参数间关系 ,探讨了该方法应用的可能性     

Elemental and individual particle analysis of atmospheric aerosols from high Himalayas

Atmospheric aerosols were collected during the scientific expedition to Mt. Qomolangma (Everest) in May–June, 2005. The elemental concentrations of the aerosols were determined by inductively coupled plasma mass spectrometry. This yielded data for the concentration of 14 elements: Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, and Pb. The mean elemental concentrations were generally comparable with those from central Asia and the Arctic, while much higher than those from Antarctic. Size, morphology, and chemical composition of 900 individual aerosol particles were determined by scanning electron microscopy and energy-dispersive X-ray microanalysis. Based on morphology and elemental composition, the particles were clustered into eight groups: soot (8%), tar ball (3%), alumosilicates/silica (55%), calcium sulfate (16%), Ca/Mg carbonate (2%), Fe/Ti-rich particles (3%), Pb-rich particles (1%), and biological particles (12%). The sampling site, located at 6,520 m in the Himalayas, is particularly remote and located at high altitude. Nonetheless, high aerosol enrichment factors for copper, chromium, lead, nickel, vanadium, and zinc all suggest the influence of long-range transported pollution, while enrichment in calcium and the presence of alumino-silicates in individual particle analyses indicates a distinct mineral dust influence. The backward air mass trajectories showed that the northwestern part of India may contribute to the atmospheric aerosol in the central high Himalayas.     

衡山云水总过氧化氢的浓度特征及气象影响因素

于2009年3月11日—5月29日在衡山采集云雾水样品,采用荧光分光光度法对样品中的总过氧化氢浓度进行了测定,分析了衡山云雾水中总过氧化氢的浓度特征及气象影响因素。结果表明,衡山云雾水中总过氧化氢平均浓度为8.46 μmol/L,呈现出明显的日夜浓度差异。分析风向、风速、辐射强度和温度对云雾水总过氧化氢浓度的影响,发现总过氧化氢浓度与风速间存在明显的负相关关系,风向主要来自海洋时,其浓度较高,来自陆地时则较低,这与来自陆地的气流携带有大量的氮氧化物和二氧化硫有关。此外,总过氧化氢浓度随温度的升高具有明显增加的趋势,且当辐射强度大于50 w/m²时,总过氧化氢与辐射强度呈良好的正相关,相关系数为0.713,说明总过氧化氢的浓度分布与光化学反应关系密切。     

Simulations of the impacts of building height layout on air quality in natural-ventilated rooms around street canyons

Numerical simulations were conducted to investigate the effects of building height ratio (i.e., HR, the height ratio of the upstream building to the downstream building) on the air quality in buildings beside street canyons, and both regular and staggered canyons were considered for the simulations. The results show that the building height ratio affects not only the ventilation fluxes of the rooms in the downstream building but also the pollutant concentrations around the building. The parameter, outdoor effective source intensity of a room, is then proposed to calculate the amount of vehicular pollutants that enters into building rooms. Smaller value of this parameter indicates less pollutant enters the room. The numerical results reveal that HRs from 2/7 to 7/2 are the favorable height ratios for the regular canyons, as they obtain smaller values than the other cases. While HR values of 5/7, 7/7, and 7/5 are appropriate for staggered canyons. In addition, in terms of improving indoor air quality by natural ventilation, the staggered canyons with favorable HR are better than those of the regular canyons.     

Effects of biochar addition on greenhouse gas emissions and microbial responses in a short-term laboratory experiment

Biochar application to soil has drawn much attention as a strategy to sequester atmospheric carbon in soil ecosystems. The applicability of this strategy as a climate change mitigation option is limited by our understanding of the mechanisms responsible for the observed changes in greenhouse gas emissions from soils, microbial responses, and soil fertility changes. We conducted an 8-wk laboratory incubation using soils from PASTURE (silt loam) and RICE PADDY (silt loam) sites with and without two types of biochar (biochar from swine manure [CHAR-M] and from barley stover [CHAR-B]). Responses to addition of the different biochars varied with the soil source. Addition of CHAR-B did not change CO and CH evolution from the PASTURE or the RICE PADDY soils, but there was a decrease in NO emissions from the PASTURE soil. The effects of CHAR-M addition on greenhouse gas emissions were different for the soils. The most substantial change was an increase in NO emissions from the RICE PADDY soil. This result was attributed to a combination of abundant denitrifiers in this soil and increased net nitrogen mineralization. Soil phosphatase and N-acetylglucosaminidase activity in the CHAR-B-treated soils was enhanced compared with the controls for both soils. Fungal biomass was higher in the CHAR-B-treated RICE PADDY soil. From our results, we suggest CHAR-B to be an appropriate amendment for the PASTURE and RICE PADDY soils because it provides increased nitrogen availability and microbial activity with no net increase in greenhouse gas emissions. Application of CHAR-M to RICE PADDY soils could result in excess nitrogen availability, which may increase NO emissions and possible NO leaching problems. Thus, this study confirms that the ability of environmentally sound biochar additions to sequester carbon in soils depends on the characteristics of the receiving soil as well as the nature of the biochar.     

The study on biomass fraction estimate methodology of municipal solid waste incinerator in Korea

In Korea, the amount of greenhouse gases released due to waste materials was 14,800,000 t CO₂eq in 2012, which increased from 5,000,000 t CO₂eq in 2010. This included the amount released due to incineration, which has gradually increased since 2010. Incineration was found to be the biggest contributor to greenhouse gases, with 7,400,000 t CO₂eq released in 2012. Therefore, with regards to the trading of greenhouse gases emissions initiated in 2015 and the writing of the national inventory report, it is important to increase the reliability of the measurements related to the incineration of waste materials.

This research explored methods for estimating the biomass fraction at Korean MSW incinerator facilities and compared the biomass fractions obtained with the different biomass fraction estimation methods. The biomass fraction was estimated by the method using default values of fossil carbon fraction suggested by IPCC, the method using the solid waste composition, and the method using incinerator flue gas.

The highest biomass fractions in Korean municipal solid waste incinerator facilities were estimated by the IPCC Default method, followed by the MSW analysis method and the Flue gas analysis method. Therefore, the difference in the biomass fraction estimate was the greatest between the IPCC Default and the Flue gas analysis methods. The difference between the MSW analysis and the flue gas analysis methods was smaller than the difference with IPCC Default method. This suggested that the use of the IPCC default method cannot reflect the characteristics of Korean waste incinerator facilities and Korean MSW.

Implications: Incineration is one of most effective methods for disposal of municipal solid waste (MSW). This paper investigates the applicability of using biomass content to estimate the amount of CO₂ released, and compares the biomass contents determined by different methods in order to establish a method for estimating biomass in the MSW incinerator facilities of Korea. After analyzing the biomass contents of the collected solid waste samples and the flue gas samples, the results were compared with the Intergovernmental Panel on Climate Change (IPCC) method, and it seems that to calculate the biomass fraction it is better to use the flue gas analysis method than the IPCC method. It is valuable to design and operate a real new incineration power plant, especially for the estimation of greenhouse gas emissions.