Organic aerosol molecular composition and gas–particle partitioning coefficients at a Mediterranean site (Corsica)

Molecular speciation of atmospheric organic matter was investigated during a short summer field campaign performed in a citrus fruit field in northern Corsica(June 2011). Aimedat assessing the performance on the field of newly developed analytical protocols, this work focuses on the molecular composition of both gas and particulate phases and provides an insight into partitioning behavior of the semi-volatile oxygenated fraction. Limonene ozonolysis tracers were specifically searched for, according to gas chromatography–mass spectrometry(GC–MS) data previously recorded for smog chamber experiments. A screening of other oxygenated species present in the field atmosphere was also performed. About sixty polar molecules were positively or tentatively identified in gas and/or particle phases. These molecules comprise a wide range of branched and linear, mono and di-carbonyls(C_3–C7),mono and di-carboxylic acids(C_3–C_18), and compounds bearing up to three functionalities.Among these compounds, some can be specifically attributed to limonene oxidation and others can be related to α- or β-pinene oxidation. This provides an original snapshot of the organic matter composition at a Mediterranean site in summer. Furthermore, for compounds identified and quantified in both gaseous and particulate phases, an experimental gas/particle partitioning coefficient was determined. Several volatile products, which are not expected in the particulate phase assuming thermodynamic equilibrium, were nonetheless present in significant concentrations. Hypotheses are proposed to explain these observations, such as the possible aerosol viscosity that could hinder the theoretical equilibrium to be rapidly reached.     

Relating Cd2 + binding by humic acids to molecular weight: A modeling and spectroscopic study

Molecular weight(Mw) is a fundamental property of humic acids(HAs), which considerably affect the mobility and speciation of heavy metals in the environment. In this study, soil humic acid(HA) extracted from Jinyun Mountain, Chongqing was ultra-filtered into four fractions according to the molecular weight, and their properties were characterized.Complexation of cadmium was investigated by titration experiments. For the first time,Langmuir and non-ideal competitive adsorption-Donna(NICA-Donnan) models combined with fluorescence excitation-emission matrix(EEM) quenching were employed to elucidate the binding characteristics of individual Mw fractions of HA. The results showed that the concentration of acidic functional groups decreased with increasing Mw, especially the phenolic groups. The humification degree and aliphaticity increased with increasing Mw as indicated by elemental composition analysis and FT-IR spectra. The binding capacity of Cd~(2+) to Mw fractions of HA followed the order UF1( 5 kDa) UF2(5–10 kDa) UF4( 30 kDa) UF3(10–30 kDa). Moreover, the distribution of cadmium speciation indicated that the phenolic groups were responsible for the variations in binding of Cd~(2+) among different Mw fractions. The results of fluorescence quenching illustrated that the binding capacity of Cd~(2+) to Mw fractions was controlled by the content of functional groups, while the binding affinity was largely influenced by structural factors. The results provide a better understanding of the roles that different HA Mw fractions play in heavy metal binding,which has important implications in the control of heavy metal migration and bio-toxicity.     

Prediction of aqueous solubility of PCBs based on molecular structure

The thermodynamic relationships among aqueous solubility and molar volume (MV) , total molecular surface area (TSA) and molecular connectivity index (MCI) for highly hydrophobic chemicals. PCBs are established and discussed, respectively. Good linear relationships exist among In Cs and MV, TSA or MCI.     

Mesoporous molecular sieve-based materials for catalytic oxidation of VOC: A review

As the main contributor of the formation of particulate matter as well as ozone, volatile organic compounds(VOCs) greatly affect human health and the environmental quality. Catalytic combustion/oxidation has been viewed as an efficient, economically feasible and environmentally friendly way for the elimination of VOCs. Supported metal catalyst is the preferred type of catalysts applied for VOCs catalytic combustion because of the synergy between active components and support as well as its flexi...     

Do anthropogenic transports facilitate stored-product pest moth dispersal? A molecular approach

Stored-product moths cause large economic damage in food processing industries and storage facilities. Control of indoor pests is currently dealt with locally, and control strategies seldom include different mills or cooperative industries in joint efforts to reduce infestations. In colder climates where conditions hinder flight dispersal of stored-product moths, we hypothesize that human transport between mills will facilitate dispersal. Albeit considered intuitive, this hypothesis has so far never been tested. Male moths from three mills (populations) in southern Sweden and Denmark were collected and by using amplified fragment length polymorphism (AFLP) pair-wise F(st) values were calculated. Cluster (population) origins of the genotypes were computed by using a model-based method, structure. The results suggest that known transportation of flour between two mills generate genetically more similar populations of the economically important stored-product moth, Ephestia kuehniella (Zell.) (Lepidoptera; Pyralidae), compared to the third mill, with another distribution area, but situated geographically in between the other mills. The structure model placed the sampled genotypes to belong to either two or five original populations, with a higher probability of two original populations. The third mill was consistently different from the other two mills independent of the models' calculated number of populations. Although the study was restricted to three mills and one transportation route, it highlights the possibility that transportation of food products promotes genetic mixing (i.e. dispersal) of insect pest populations. Including cooperating mills in control (or monitor) strategy schemes against stored-product pest insects would therefore be a more effective action, rather than to treat each mill separately.     

Three industries and wastewater and COD discharge of Beijing

Ｒｅｃｅｎｔｌｙ,ｗｉｔｈｔｈｅｓｗｉｆｔｄｅｖｅｌｏｐｍｅｎｔｏｆｅｃｏｎｏｍｙａｎｄｔｈｅｉｍｐｒｏｖｅｍｅｎｔｏｆｐｅｏｐｌｅ′ｓｌｉｖｉｎｇｓｔａｎｄａｒｄ ,ｔｈｅｗａｔｅｒｕｓｅａｍｏｕｎｔａｎｄｗａｓｔｅｗａｔｅｒｄｉｓｃｈａｒｇｅｂｅｃｏｍｅｂｉｇｇｅｒａｎｄｂｉｇｇｅｒ,ａｎｄｔｈｅｗａｔｅｒｑｕａｌｉｔｙｉｓｇｅｔｔｉｎｇｗｏｒｓｅａｎｄｗｏｒｓｅ .Ｓｏｉｌａｎｄａｇｒｉｃｕｌｔｕｒａｌｐｒｏｄｕｃｔｓｈａｖｅｂｅｅｎｐｏｌｌｕｔｅｄｂｙｔｈｅｗａｓｔｅｗａｔｅｒ,ａｎｄｐｅｏｐ…     

Trends and characteristics of total ozone’and vertical profile in Kunming and Beijing，China

This paper presents the trends of total ozone at Beijing and Kunming areas during the period of 1979 to 1989．The SBUV ozone vertical profile data and the periodic oscillation in upper ozone layers over Beijing area are also described．The results show that the variation of Beijing and Kunming per decade are about-5%and-1.5%．respectively．     

Methylated and thiolated arsenic species for environmental and health research——A review on synthesis and characterization

Hundreds of millions of people around the world are exposed to elevated concentrations of inorganic and organic arsenic compounds, increasing the risk of a wide range of health effects. Studies of the environmental fate and human health effects of arsenic require authentic arsenic compounds. We summarize here the synthesis and characterization of more than a dozen methylated and thiolated arsenic compounds that are not commercially available. We discuss the methods of synthesis for the following14 trivalent(Ⅲ) and pentavalent() arsenic compounds: monomethylarsonous acid(MMA~Ⅲ), dicysteinylmethyldithioarsenite(MMA~Ⅲ(Cys)_2), monomethylarsonic acid(MMA~Ⅴ),monomethylmonothioarsonic acid(MMMTAⅤ) or monothio-MMA~Ⅴ, monomethyldithioarsonic acid(MMDTA~Ⅴ) or dithio-MMA~Ⅴ, monomethyltrithioarsonate(MMTTA~Ⅴ) or trithio-MMA~Ⅴ,dimethylarsinous acid(DMA~Ⅲ), dimethylarsino-glutathione(DMA~Ⅲ(SG)), dimethylarsinic acid(DMA~Ⅴ), dimethylmonothioarsinic acid(DMMTA~Ⅴ) or monothio-DMAⅤ, dimethyldithioarsinic acid(DMDTA~Ⅴ) or dithio-DMA~Ⅴ, trimethylarsine oxide(TMAO~Ⅴ), arsenobetaine(AsB), and an arsenicin-A model compound. We have reviewed and compared the available methods,synthesized the arsenic compounds in our laboratories, and provided characterization information. On the basis of reaction yield, ease of synthesis and purification of product, safety considerations, and our experience, we recommend a method for the synthesis of each of these arsenic compounds.     

β-Cyclodextrin and its derivatives-enhanced solubility and biodegradation of 2-nitrobiphenyl

This paper investigated the effects of β-cyclodextrins （I3-CD） and its two derivatives, hydroxypropyl-β-cyclodextrin （HPCD） and carboxymethyl-β-cyclodextrin （CMCD）, on the solubility and biodegradation of 2-nitrophenyl by an A cinetbacter sp. Results showed that β-CD, HPCD and CMCD could not be utilized by A cinetbacter sp. as sole carbon source and none of the CDs had toxic effects on the growth of the bacteria in the experiments; all the CDs could enhance the apparent solubility and accelerate the biodegradation of 2-nitrobipheny. It showed that biodegradation-accelerating effects of CDs on 2-nitrobiphenyl were correlated with their solubility-enhancing effects. Among three CDs investigated, CMCD had the most obvious effects both on the apparent solubility and the biodegradation, followed by β-CD and HPCD.     

Chemical behavior and risk assessment of four pesticidesin soil and water

ＣｈｅｍｉｃａｌｂｅｈａｖｉｏｒａｎｄｒｉｓｋａｓｓｅｓｓｍｅｎｔｏｆｆｏｕｒｐｅｓｔｉｃｉｄｅｓｉｎｓｏｉｌａｎｄｗａｔｅｒＪｉａｎｇＸｉｌｉｕ；ＨｕａＸｉａｏｍｅｉ（ＮａｎｊｉｎｇＩｎｓｔｉｔｕｔｅｏｆＥｎｖｉｒｏｎｒｎｅｎｔＳｃｉｅｎｃｅ，Ｎａ...     

Dynamic simulation and modeling of PCP transport between sediment and water

ＤｙｎａｍｉｃｓｉｍｕｌａｔｉｏｎａｎｄｍｏｄｅｌｉｎｇｏｆＰＣＰｔｒａｎｓｐｏｒｔｂｅｔｗｅｅｎｓｅｄｉｍｅｎｔａｎｄｗａｔｅｒＬｉＴｉｅ，ＹｅＣｈａｎｇｍｉｎｇ，ＬｅｉＺｈｉｆａｎｇＲｅｓｅａｒｃｈＣｅｎｔｅｒｆｏｒＥｃｏＥｎｖｉｒｏ...     

China''s environmental scientific research and technology development: review and envisage

Ｃｈｉｎａ’ｓｅｎｖｉｒｏｎｍｅｎｔａｌｓｃｉｅｎｔｉｆｉｃｒｅｓｅａｒｃｈａｎｄｔｅｃｈｎｏｌｏｇｙｄｅｖｅｌｏｐｍｅｎｔ：ｒｅｖｉｅｗａｎｄｅｎｖｉｓａｇｅＬｉｕＪｉａｎＢｕｒｅａｕｏｆＳ＆ＴｆｏｒＲｅｓｏｕｒｃｅｓａｎｄＥｎｖｉｒｏｎｍｅｎｔ，...     

Side-effects of organic and inorganic pollutants on soil nitrification and respiration

Ｓｉｄｅ－ｅｆｆｅｃｔｓｏｆｏｒｇａｎｉｃａｎｄｉｎｏｒｇａｎｉｃｐｏｌｌｕｔａｎｔｓｏｎｓｏｉｌｎｉｔｒｉｆｉｃａｔｉｏｎａｎｄｒｅｓｐｉｒａｔｉｏｎ￥ＧｏｎｇＰｉｎｇ；ＳｕｎＴｉｅｈｅｎｇ（ＩｎｓｔｉｔｕｔｅｏｆＡｐｐｌｉｅｄＥｃｏｌｏｇｙ，Ｃｈ...     

Geoecological analysis of the Korea alpine and subalpine plants and lands

１ＩｎｔｒｏｄｕｃｔｉｏｎＤｕｅｔｏｔｈｅｒａｐｉｄｇｌｏｂａｌｗａｒｍｉｎｇｔｒｅｎｄ，ｗｈｉｃｈｔｏｏｋｐｌａｃｅｉｎｔｈｅ２０ｔｈｃｅｎｔｕｒｙ，ｎｕｍｅｒｏｕｓｕｎｅｘｐｅｃｔｅｄｅｎｖｉｒｏｎｍｅｎｔａｌａｎｄｅｃｏｌｏｇｉｃａｌｉｓｕｅｓ...