Source profiles of particulate organic matters emitted from cereal straw burnings

Cereal straw is one of the most abundant biomass burned in China but its contribution to fine particulates is not adequately understood. In this study, three main kinds of cereal straws were collected from five grain producing areas in China. Fine particulate matters （PMzs） from the cereal straws subjected to control burnings, both under smoldering and flaming status, were sampled by using a custom made dilution chamber and sampling system in the laboratory. Element carbon （EC） and organic carbon （OC） was analyzed. 141 compounds of organic matters were measured by gas chromatography-mass spectrum （GC-MS）. Source profiles of particulate organic matters emitted from cereal straw burnings were obtained. The results indicated that organic matters contribute a large fraction in fine particulate matters. Levoglucosan had the highest contributions with averagely 4.5% in mass of fine particulates and can be considered as the tracer of biomass burnings. Methyloxylated phenols from lignin degradation also had high concentrations in PM2.5, and contained approximately equal amounts of guaiacyl and syringyl compounds. 13-Sitostrol also made up relatively a large fraction of PMz5 compared with the other sterols （0.18%-0.63% of the total fine particle mass）. Normal alkanes, PAHs, fatty acids, as well as normal alkanols had relatively lower concentrations compared with the compounds mentioned above. Carbon preference index （CPI） of normal alkanes and alkanoic acids showed characteristics of biogenic fuel burnings. Burning status significantly influenced the formations of EC and PAHs. The differences between the emission profiles of straw and wood combustions were displayed by the fingerprint compounds, which may be used to identify the contributions between wood and straw burnings in source apportionment researches.

Development of source profiles and their application in source apportionment of PM2.5 in Xiamen, China

Ambient PM2.5 samples were collected at four sites in Xiamen, including Gulangyu （GLY）. Hongwen （HW）, Huli （HL） and Jimei （JM） during January, April, July and October 2013. Local source samples were obtained from coal burning power plants, industries, motor vehicles, biomass burning, fugitive dust, and sea salt for the source apportionment studies. The highest value of PM2.5 mass concentration and species related to human activities （SO42- , NO3 , Pb, Ni, V, Cu, Cd, organic carbon （OC） andelemental carbon （EC）） were found in the ambient-samples from HL, and t-he highest and lowest loadings of PM2.5 and its components occurred in winter and summer, respectively. The reconstructed mass balance indicated that ambient PM2.5 consisted of 24% OM （organic matter）, 23% sulfate, 14% nitrate, 9% ammonium, 9% geological material, 6% sea salt, 5% EC and 10% others. For the source profiles, the dominant components were OC for coal burning, motor vehicle, biomass burning and sea salt; SO42 for industry; and crustal elements for fugitive dust. Source contributions were calculatedusing a chemical mass＇balance （CMB） model basedon ambient PM2.5 concentrations and the source profiles. GLY was characterized by high contributions from secondary sulfate and cooking, while HL and JM were most strongly affected by motor vehicle emissions, and biomass burning and fugitivedust, respectively. The CMB results-indicated that PM2.5 from Xiamen is composed of 27.4% secondary inorganic components, 20.8% motor vehicle emissions, 11.7% fugitive dust, 9.9% sea salt, 9.3% coal burning, 5.0% biomass burning, 3.1% industry and 6.8% others.

SOURCE PROFILES AND FINGERPRINTS OF FINE AND COARSE SANDS RESUSPENDED FROM SOILS SAMPLED IN CENTRAL INNER MONGOLIA

Fingerprints and source profiles of fine and coarse sands that originate from Central Inner Mongolia during Asian continental sandstorms （ACS） can be used to identify the odgin of Asian sands and to trace them as they travel downwind. Soil samples collected at various land surfaces in Central Inner Mongolia were resuspended using a dry powder atomizer in an enclosure chamber. The resuspended sands were then sampled by two dichotomous samplers situated at the bottom of the enclosure chamber for fine （PM2 5） and coarse （PM2.5-10） sands, respectively. The chemical composition of sands, including water-soluble ionic species, metallic contents, and carbonaceous contents, were further analyzed. Results from resuspension tests indicated that the soils contained considerably more coarse particles than fine Moreover, Mg, K, Al, and Fe in coarse sand had strong correlations with each other. The ratio of Mg, K. Fe （or Al） to Al （or Fe） and OC/EC in the coarse sands can be used as the fingerprints of Asian sands originating from Central Inner Mongolia.

Analysis of Nutrient Profile of Finger Millet(Eleusine coracana(L.)Gaertn.)for Baby Food Formulation Using Pigeon Pea(Cajanus cajan(L.)Millsp.)as Protein Source

Finger millet(Eleusine coracana(L.)Gaertn.)is a drought resistant crop with potentially tremendous but under-explored source of nutraceutical properties as compared to other regularly consumed cereals in the era of drawback of nutritional security,these characteristics must be harnessed to develop finger millet as a novel functional food.Under-nutrition caused by inadequate diets,and other factors that influence nutritional status,is the underlying factor in 45%child deaths.In Kenya only 25%of young children are fed adequately diverse diets.The main objective of this study was to prepare baby food formulas using finger millets with pigeon peas as protein source and to analyze their nutritional profiles.Two finger millets varieties(i)Snapping Green Early,low altitude and medium altitude varieties and(ii)U-15)were studied to determine effects of environment on nutrient profiles.This study showed that Snapping Green Early had better nutrient profiles(12.13%protein and is high in Ca,Mg,Fe,Zn and P)than U-15(11.69%protein and lower nutrients(Ca,Mg,Fe,Zn and P)),and hence was selected for use in the malting process as best variety.As expected,the pigeon peas had the highest protein value(21%).The samples malted for 72 h resulted in reduction of tannin concentration from 0.091%to 0.03%and the amount of nutrients(Ca,Mg,Fe and Zn)doubled and in fact the protein profile increased by 8.31%.The appropriate ratio for the formulation of the baby food was 70:30.The composting resulted in 18.5%increase in protein.

Source apportionment and suitability evaluation of seasonal VOCs contaminants in the soil around a typical refining-chemical integration park in China

Accurate source apportionment of volatile organic compounds(VOCs)in soil nearby petrochemical industries prevailing globally,is critical for preventing pollution.However,in the process,seasonal effect on contamination pathways and accumulation of soil VOCs is often neglected.Herein,Yanshan Refining-Chemical Integration Park,including a carpet,refining,synthetic rubber,and two synthetic resin zones,was selected for traceability.Season variations resulted in a gradual decrease of 31 VOCs in soil from winter to summer.A method of dry deposition resistance model coupling partitioning coefficient model was created,revealing that dry deposition by gas phase was the primary pathway for VOCs to enter soil in winter and spring,with 100 times higher fux than by particle phase.Source profiles for five zones were built by gas sampling with distinct substance indicators screened,which were used for positive matrix factorization factors determination.Contributions of the five zones were 14.9%,20.8%,13.6%,22.1%,and 28.6%in winter and 33.4%,12.5%,10.7%,24.9%,and 18.5%in spring,respectively.The variation in the soil sorption capacity of VOCs causes inter-seasonal differences in contribution.The better correlation between dry deposition capacity and soil storage of VOCs made root mean square and mean absolute errors decrease averagely by 8.8%and 5.5%in winter compared to spring.This study provides new perspectives and methods for the source apportionment of soil VOCs contamination in industrial sites.

A comprehensive classification method for VOC emission sources to tackle air pollution based on VOC species reactivity and emission amounts

In China, volatile organic compound（VOC） control directives have been continuously released and implemented for important sources and regions to tackle air pollution. The corresponding control requirements were based on VOC emission amounts（EA）, but never considered the significant differentiation of VOC species in terms of atmospheric chemical reactivity. This will adversely influence the effect of VOC reduction on air quality improvement. Therefore,this study attempted to develop a comprehensive classification method for typical VOC sources in the Beijing–Tianjin–Hebei region（BTH）, by combining the VOC emission amounts with the chemical reactivities of VOC species. Firstly, we obtained the VOC chemical profiles by measuring 5 key sources in the BTH region and referencing another 10 key sources, and estimated the ozone formation potential（OFP） per ton VOC emission for these sources by using the maximum incremental reactivity（MIR） index as the characteristic of source reactivity（SR）. Then, we applied the data normalization method to respectively convert EA and SR to normalized EA（NEA） and normalized SR（NSR） for various sources in the BTH region.Finally, the control index（CI） was calculated, and these sources were further classified into four grades based on the normalized CI（NCI）. The study results showed that in the BTH region,furniture coating, automobile coating, and road vehicles are characterized by high NCI and need to be given more attention; however, the petro-chemical industry, which was designated as an important control source by air quality managers, has a lower NCI.

Surrogate atmospheric dust particles generated from dune soils in laboratory: Comparison with field measurement

Desert dust strongly influences the climate and the environment by altering the radiation budget, participating in atmospheric chemical reactions, and engaging the biogeochemical cycle. Studying its impacts requires knowledge of the physical and chemical properties of the original particles from the source origin. Unfortunately, the field collection of atmospheric samples in the desert is impractical. Fine surface soil is thus considered an alternative material from which to obtain the information applicable to dust particles from the desert soil. In this study, a laboratory system was set up to generate dust particles with simulated natural wind erosion processes from surface soils or directly from desert surfaces. Surface soils and field dust were simultaneously collected during a local blowing dust event. The comparison between the laboratory-generated dust and the field dust showed a consistent trend in particle size distribution and chemical composition. The chemical compositions were found to have explainable differences with the Certified Reference Materials for Asian dust (CJ-2). The laboratory-generated dust particles with the system could be applied as surrogates for soil-emitted dust in desert areas.

Size distribution and chemical characteristics of particles from crop residue open burning in North China

Crop residue open burning is an important emission source of ambient particles in China.This study analyzed the particle emission characteristics of crop residue open burning through combustion experiments with a novel open combustion simulation device using three typical crop straws in north China(corn,wheat,and rice).Particle samples size ranging from 0.006–9.890μm were collected by an Electrical Low Pressure Impactor plus,a high size-resolution instrument capable of dividing particles into 14 size stages.The size distributions of organic carbon(OC),elemental carbon(EC),water-soluble ions,and elements were analyzed,and source chemical profiles were constructed for PM0.1,PM1,PM2.5,and PM10.The number concentration of particles was concentrated in the Aiken nuclei mode(0.006–0.054μm),accounting for 75%of the total number,whereas the mass concentration was concentrated in the accumulation mode(0.054–0.949μm),accounting for 85.43%of the mass loading.OC,EC,Cl−,and K(include total K and water-soluble K)were the major chemical components of the particles,whose mass percentage distributions differed from those of other components.These fivemain components exhibited a bell-shaped size distribution in the 0.006–9.890μm range,whereas the other components exhibited a U-shaped distribution.Among the chemical profiles for PM0.1–PM10,OC was the most important component at 10–30%,followed by EC at 2%–8%.The proportions of K^(+),Cl^(−),and K varied substantially in different experimental groups,ranging from 0–15%,and K+and Cl−were significantly correlated(r=0.878,α=0.000).