Second organic aerosol formation from the ozonolysis of α-pinene in the presence of dry submicron ammonium sulfate aerosol

An indoor chamber facility is described for investigation of atmospheric aerosol chemistry. Two sets of α-pinene ozonolysis experiments were conducted in the presence of dry ammonium sulfate seed particle: ozone limited experiments and α-pinene limited experiments. The concentration of gas phase and particle phase species was monitored continuously by on-line instruments and recorded automatically by data sampling system. The evolution of size distribution was measured by a scanning mobility particle sizer ...     

Competing esterification and oligomerization reactions of typical long-chain alcohols to secondary organic aerosol formation

Organosulfate (OSA) nanoparticles,as secondary organic aerosol (SOA) compositions,are ubiquitous in urban and rural environments.Hence,we systemically investigated the mechanisms and kinetics of aqueous-phase reactions of 1-butanol/1-decanol (BOL/DOL) and their roles in the formation of OSA nanoparticles by using quantum chemical and kinetic calculations.The mechanism results show that the aqueous-phase reactions of BOL/DOL start from initial protonation at alcoholic OH-groups to form carbenium ...     

Effect of illumination intensity and light application time on secondary organic aerosol formation from the photooxidation of α-pinene

Secondary organic aerosol (SOA) formation from hydroxyl radical (OH.) initiated photooxidation of α-pinene was investigated in a home-made smog chamber. The size distribution of SOA particles was measured using aerodynamic particle sizer spectrometer. The effects of illumination intensity and light application time on SOA formation for α-pinene were evaluated. Experimental results show that the concentration of SOA particles increased significantly with an increasing of illumination intensity, and the light...     

Present status of aerosol research in China

１ＩｎｔｒｏｄｕｃｔｉｏｎＡｅｒｏｓｏｌｓｐｌａｙａｎｉｍｐｏｒｔａｎｔｒｏｌｅｉｎｃｌｉｍａｔｅｃｈａｎｇｅ，ａｉｒｑｕａｌｉｔｙ，ａｃｉｄｄｅｐｏｓｉｔｉｏｎ，ｖｉｓｉｂｉｌｉｔｙｒｅｄｕｃｔｉｏｎ，ａｎｄｃｌｏｕｄｐｒｏｃｅｓｅｓ．Ｔｈｅｙａｒ...     

Characteristics of the natural organic matter sorption affects of organic contaminants

ＩｎｔｒｏｄｕｃｔｉｏｎＲｅｃｅｎｔｒｅｓｅａｒｃｈｈａｓｄｅｍｏｎｓｔｒａｔｅｄｔｈａｔｓｏｒｐｔｉｏｎｏｆｈｙｄｒｏｐｈｏｂｉｃｏｒｇａｎｉｃｃｏｍｐｏｕｎｄｓ(ＨＯＣ)ｉｎｓｏｉｌｓａｎｄｓｅｄｉｍｅｎｔｓｉｓｃｏｎｔｒｏｌｌｅｄｂｙｏｒｇａｎｉｃｍａｔｔｅｒｕｎｌｅｓｓｉｔｓｃｏｎｔｅｎｔｉｓｖｅｒｙｌｏｗ(Ｃｈｉｏｕ ,1 989) .Ｔｈｉｓｉｓｐａｒｔｉｃｕｌａｒｌｙｔｒｕｅｉｎｗａｔｅｒ ｓｏｉｌｓｙｓｔｅｍｓｂｅｃａｕｓｅｗａｔｅｒｍｏｌｅｃｕｌｅｓａｒｅｐｒｅｆｅｒａｂｌｙａｄｓｏｒｂｅｄ…     

The role of atmospheric aerosol composition in climate change

The chemical composition of atmospheric aerosols has been investigated. Contributions ofsulfate and soot in aerosols to the atmospheric extinction are studied. Discussions are made on the problems of aerosol emitted from volcano, forest fires in northern China, 1987 and oil field fires in Kuwait, 1991. It is indicated that the changes in concentration, particle size, and chemical composition of aerosol after those events could have impacts on the climate change either regionally or globally and that the impact of aerosol particles on climate change could compensate for some temperature increase caused by greenhouse gases and the increase of surface intensity of ultraviolet radiation due to ozone layer depletion.     

Study of aerosol composition in some clean areas of China

On Peak Namjagbarwa (Tibet Plateau), Lushan Mountain (Province Jiangxi), Flower Mountain and Shangdianzi (Beijing, near Great Wall) aerosol samples have been collected by cascade samplers. For comparison aerosol samples from Beijing City, Pacific Ocean and South Pole also have been collected. Samples were analyzed with PIXE or XFA instruments. Factor analysis and enrichment factor calculation were performed to process the data.     

Conversion of organic carbon in the decomposable organic wastes in anaerobic lysimeters under different temperatures

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｐｒｏｐｏｒｔｉｏｎｏｆｄｅｃｏｍｐｏｓａｂｌｅｏｒｇａｎｉｃｗａｓｔｅｓｓｕｃｈａｓｆｏｏｄｏｒｉｇｉｎｗａｓｔｅｓａｎｄｂａｃｋｙａｒｄｗａｓｔｅｓ ,ｉｎｍｕｎｉｃｉｐａｌｓｏｌｉｄｗａｓｔｅｓｉｎＳｈａｎｇｈａｉ,Ｃｈｉｎａ,ｈａｓｂｅｅｎｉｎｃｒｅａｓｉｎｇｒａｐｉｄｌｙ ,ａｓｔｈｅｌｉｖｉｎｇｓｔａｎｄａｒｄｏｆｉｎｈａｂｉｔａｎｔｓｉｎｔｈｅｃｉｔｙａｒｅｒｅｍａｒｋａｂｌｙｉｍｐｒｏｖｉｎｇｉｎｒｅｃｅｎｔｙｅａｒｓ .Ｆｏｒｅｘａｍｐｌｅ ,ａｒｏｕｎｄ 1…     

Collecting aerosol in airflow with a magnetically stabilized fluidized bed

ＩｎｔｒｏｄｕｃｔｉｏｎＧｒａｎｕｌａｒｆｉｘｅｄｆｉｌｔｅｒｓｈａｖｅｂｅｅｎｗｉｄｅｌｙｕｓｅｄｉｎｉｎｄｕｓｔｒｙｄｕｅｔｏｍａｎｙｏｆｔｈｅｉｒａｄｖａｎｔａｇｅｓ,ｓｕｃｈａｓｈｉｇｈｃｏｌｌｅｃｔｉｏｎｅｆｆｉｃｉｅｎｃｙ,ｗｅａｒ,ｃｏｒｒｏｓｉｏｎａｎｄｈｅａｔｒｅｓｉｓｔａｎｃｅａｎｄｓｏｏｎ (Ｄ’Ｏｔｔａｖｉｏ ,1978) .Ｈｏｗｅｖｅｒ ,ｏｎｅｄｒａｗｂａｃｋｏｆｇｒａｎｕｌａｒｆｉｘｅｄｆｉｌｔｅｒｓｉｓｔｈａｔｔｈｅｙｃａｎｎｏｔｗｏｒｋｃｏｎｔｉｎｕｏｕｓｌｙｆｏｒａｌｏｎｇ…     

Fouling of nanofiltration membrane by effluent organic matter： Characterization using different organic fractions in wastewater

The UF membrane with molecular weight cutoff (MWCO) ranging from 2 kDa to 100 kDa and XAD-8 resin were employed to identify the characteristic of molecular weight (MW) distribution of wastewater effluent organic matter (EfOM) in terms of TOC and UV254, as well as the amounts of the hydrophilic/hydrophobic organic fractions in different MW ranges. Then, the nanofiltration (NF) membrane fouling experiments were carried out using the above fractionated water to investigate the effect of MW distribution and hydrophilic/hydrophobic characteristics of EfOM on the membrane flux decline using the fractionated water samples above. The experimental results have shown that 45.61% of the total organics belongs to the low MW one, among which the percentage of the hydrophilic organics with low MW (less than 2 kDa) was up to 28.07%, while that of the hydrophobic organics was 17.54%. In particular, the hydrophilic fraction was found to be the most abundant fraction in the effluents. MW distribution has a significant effect on the membrane fouling. When the MW was less than 30 kDa, the lower the MW, the larger was the specific flux decline, while in the case of MW higher than 30 kDa, the higher the MW, the larger was the specific flux decline, and the decline degree of low MW organics was larger than the high MW one. With the same MW distribution range, specific flux decline of the hydrophilic organic was considerably slower than that of the hydrophobic organic, which indicated that the hydrophobic organic fractions dominantly contribute to the flux decline.     

Free radical oxidation of spent radioactive organic solvent

ＦｒｅｒａｄｉｃａｌｏｘｉｄａｔｉｏｎｏｆｓｐｅｎｔｒａｄｉｏａｃｔｉｖｅｏｒｇａｎｉｃｓｏｌｖｅｎｔＪｉＸｉａｏｙｕａｎ，ＺｈａｏＢｉｎＩｎｓｔｉｔｕｔｅｏｆＮｕｃｌｅａｒＥｎｅｒｇｙＴｅｃｈｎｏｌｏｇｙ，ＴｓｉｎｇｈｕａＵｎｉｖｅｒｓｉｔｙ，Ｂｅ...     

Analysis of organic compounds in coal gasification wastewater

A procedure for analysis of organic pollutants in coal gasification wastewater was developed, including a series extraction steps at different pH, followed by LC separation or resin adsorption, then analyzed by GC or GC/MS. More than 200 organic pollutants in 22 categories were determined. CH2CL2 extraction at NaHCO3 presence was used to separate carboxylic acids with phenolic compounds in aqueous. Derivatization with acetic anhydride was used for analyses of mono-, di-, poly-hydroxyl phenolic compounds. 21 mono-hydroxyl phenols and 13 di-hydroxyl phenols were determined from the coai gasification wastewater samples. Derivatization with BF3-CH3OH was used for analysis of carboxylic acid. 17 mono-carboxyl, 4 di-carboxyl acids and 6 aromatic acids were determined from coal gasification wastewater samples.     

Phytoremediation and its models for organic contaminated soils

ＩｎｔｒｏｄｕｃｔｉｏｎＳｏｉｌｓａｒｅａｓｉｎｋｆｏｒｏｒｇａｎｉｃｐｏｌｌｕｔａｎｔｓｏｆｃｏｎｃｅｒｎｆｏｒｈｕｍａｎａｎｄｅｎｖｉｒｏｎｍｅｎｔａｌｈｅａｌｔｈａｎｄｓｕｓｔａｉｎａｂｉｌｉｔｙ .Ｓｏｍｅｏｒｇａｎｉｃｐｏｌｌｕｔａｎｔｓａｒｒｉｖｉｎｇｉｎｓｏｉｌｓｃａｎｂｅｒａｐｉｄｌｙｄｅｃｏｍｐｏｓｅｄ ,ｗｈｉｌｓｔｇｒｅａｔａｍｏｕｎｔｏｆｏｒｇａｎｉｃｐｏｌｌｕｔａｎｔｓｓｕｃｈａｓｐｅｒｓｉｓｔｅｎｔｏｒｇａｎｉｃｐｏｌｌｕｔａｎｔｓ (ＰＯＰｓ)ｍａｙｐｅｒｓｉｓｔｉｎｓｏ…     

A test method for determining biodegradabilityof organic substances

ＡｔｅｓｔｍｅｔｈｏｄｆｏｒｄｅｔｅｒｍｉｎｉｎｇｂｉｏｄｅｇｒａｄａｂｉｌｉｔｙｏｆｏｒｇａｎｉｃｓｕｂｓｔａｎｃｅｓＭａｉＷｅｎｎｉｎｇ；ＪｉａｎｇＺｈａｎｐｅｎｇ；ＧｕＸｉａｓｈｅｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＥｎｖｉｒｏｎｍｅｎｔａｌＥｎｇｉ...     

On the study of aerosol composition at the Great Wall Station, South Pole

The South pole aera offers one of the best locations on the Earth for studying the composition of the background aerosol. For this purpose, aerosol samples were collected in particle size fractions by 8 stages cascade impactors. Aerosol sampling was begun in Jan. and finished in Dec. 1986 at the St. Great Wall, South Pole. The samples were analysed by Proton Induced X-ray Emission (PIXE) method. In order to learn the enrichment factors of various elements all the results were separated into two groups: coarse (> 10μm) and fine (< 10μm) particles. The correlation coefficients of elements of both coarse and fine particles were discussed. The aerosol levels measured at St. Great Wall were compared to those recently measured at some other locations. It can be concluded the South Pole is a good background area on the Earth.     

Fourier transform infrared analysis of aerosol formed in the photo-oxidation of isoprene and β-pinene

The chemical composition of smog-chamber aerosol generated during the photo-oxidation of isoprene and β-pinene was probed using infrared (i.r.) microscopy interfaced with a low pressure impactor. The low-pressure impactor employed ZnSe impaction surfaces which allowed direct analysis, with no extraction, using i.r. microscopy. The low detection limits of this technique, coupled with direct sample analysis, permitted the chemical analysis of aerosol generated at low to moderate hydrocarbon and ozone loadings. The quantitative analysis of the i.r. spectra is limited, in part, by the absence of calibration standards, however, it is clear that the biogenic aerosols generated in this work were liquid mixtures containing ketone, aldehyde, alcohol and organonitrate functional groups. Molar loadings of each of these functional groups were estimated for nine smog-chamber experiments. For aerosol formed in isoprene photo-oxidation, aldehyde and ketone groups dominated (1.8 groups per average molecule) while for aerosol formed in β-pinene photo-oxidation, alcohols and ketones dominated (a combined 2.7 groups per average molecule).     

Effect of relative humidity and the presence of aerosol particles on the α-pinene ozonolysis

The α-pinene ozonolysis under the different environmental conditions were observed in a smog chamber. The second-order rate constant(k) was determined to be(7.25 ± 0.06) ×10~(–17)cm~3/(molecule·sec) under 20% of relative humidity(RH) and room temperature. RH showed a marked influence on the α-pinene ozonolysis. The value of k increased with RH increase, which was 1.6 times faster at RH = 80% than that at RH = 20%. Additionally, the value of k apparently changed in the presence of the aerosol particles. The diesel soot increased the k value. The fly ash prohibited the reaction, however, H_2SO_4-treated fly ash promoted the reaction. The information of products gained using FT-IR and SPAMS showed that pinonic acid, 10-hydroxy-pinonic acid and pinic acid could be generated during the α-pinene ozonolysis. Water molecules could take part in the formation of the products, and play a vital role in the degradation of α-pinene. The atmospheric residence time calculation showed that the ozonolysis in the atmosphere is an important way of the α-pinene consumption as compared to that reacted with OH during daytime. The results suggested that the degradation of α-pinene via the ozonization in the atmosphere may be affected greatly by RH, as well as the presence of aerosol particles. The ozonolysis reaction may be an important way of the α-pinene consumption during daytime.     

Overall efficiency of tubular inlets sampling at 0–90 degrees from horizontal aerosol flows

We have developed a unified and comprehensive model for the overall efficiency of tubular inlets sampling from horizontal aerosol flows at 0–90° relative to the wind direction. In our model, derived from experimental data obtained in our wind tunnel, the transmission efficiency is separated into two components: one due to gravitational settling in the boundary layer and the other due to impaction. The gravitational settling component is determined by extending our previously developed isoaxial sampling model to nonisoaxial sampling. The impaction component is determined by a new model that quantifies the particle losses caused by direct wall impaction. The model also quantifies the additional particle losses resulting from the turbulent motion in the vena contracta which is formed in the inlet when the inlet velocity is higher than the wind velocity.The equation for the gravitational settling component considers the inertial behaviour of the particles by including the Stokes number, the flow development in the boundary layer by including the Reynolds number and the gravitational settling in the boundary layer by including a modified gravitational settling parameter. The equation for the impaction component considers direct wall impaction and the losses due to vena contracta formation through the Stokes number, velocity ration and sampling angle. Direct wall impaction is further differentiated by the gravity effect on the impaction process which distinguishes upward from downward sampling. Our equations for transmission efficiency in combination with aspiration efficiency equations determine the overall efficiency of tubular, sharp-edged inlets at all orientations of the inlet relative to horizontal aerosol flows.     

Contribution of organic matter to metolachlor adsorption on some soils

ＣｏｎｔｒｉｂｕｔｉｏｎｏｆｏｒｇａｎｉｃｍａｔｔｅｒｔｏｍｅｔｏｌａｃｈｌｏｒａｄｓｏｒｐｔｉｏｎｏｎｓｏｍｅｓｏｉｌｓＬｉｕＷｅｉｐｉｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｓｔｒｙ，ＺｈｅｊｉａｎｇＵｎｉｖｅｒｓｉｔｙ；Ｈａｎｇｚｈｏｕ３１００...     

A study of the aerosol of Santiago de Chile—I. Light extinction coefficients

The atmosphere of Santiago de Chile has been investigated by telephotometry in several parts of the city. Spectral extinction coefficients were measured during the time period between September 1988 and January 1989 (mid-spring to mid-summer) and again between February 1990 and June 1990 (autumn to mid-winter). The values measured show a distinct daily pattern with high values in the morning and a steady decrease in the afternoon. This pattern is attributed to a steady increase in the height of the mixing layer during daytime which allows an increasing dilution of the aerosol; unfortunately systematic measurements of vertical temperature profiles are not available for Santiago. In contrast to the urban area, measurements at an elevated site in the Andes Mountains showed a constant increase in light extinction during daytime. In the morning the extinction coefficients were similar to the background values off the coast on the Pacific. In the afternoon after expansion of the mixing layer extinction coefficients in the mountains were comparable to those in the urban area. Some sight paths were reached at later hours by the mixing layer and had a maximum of light extinction coefficient later in the morning hours. The transport of aerosols can cause dramatic changes in extinction coefficients within a short time; changes of up to a factor of five have been observed within an hour. In such cases the wavelength dependence of the aerosol underwent changes with the advection or production of a different aerosol. A comparison with the pollution of other large cities shows that the daily pattern of variation of the extinction coefficient in Santiago is different; the values of the extinction coefficients observed in Santiago de Chile are compared to those in European and Asian cities. With this study part of the complex behaviour of the Santiago atmosphere has been understood but much further work is needed. The optical technique used here has proven useful in investigating the atmosphere in real time with adequate time resolution and the possibility to make space-resolved measurements also.