Qingyue Wang

Comparison of cellular toxicity caused by ambient ultrafine particles and engineered metal oxide nanoparticles

ObjectiveThe development of nanotechnology has spurred concerns about the health effects of exposure to nanoparticles (NPs) and ultrafine particles (UFPs). Toxicological data on NPs and UFPs may provide evidence to support the development of regulations to reduce the risk of particle exposure. We tried to provide fundamental data to determine differences in cytotoxicity induced by ambient UFPs and engineered metal oxide NPs (ZnO, NiO, and CeO2).MethodsUFPs were sampled by using of a nano micro-orifice uniform deposit impactor. Physicochemical characterization of the UFPs and nano metal oxide particles were studied by scanning electron microscopy and transmission electron microscopy. Cellular toxicity induced by the different particles was assessed by using of comprehensive approaches and compared after A549 cells were exposured to the particles.ResultsAll of the measured particles could damage A549 cells at concentrations ranging from 25 to 200 μg/mL. The lowest survival ratio and the highest lactate dehydrogenase level were caused by nano-ZnO particles, but the highest levels of intracellular reactive oxygen species (ROS) and percentages of apoptosis were observed in cells treated with the soluble fraction of ambient fine particles (PM1.8) at 200 μg/mL. Relatively high concentrations of anthropogenic metals, including Zn, Ni, Fe, and Cu, may be responsible for the higher toxicity of fine ambient particles compared with the ambient coarse particles and UFPs. The selected heavy metals (Zn, Ni, Fe, and Cu) were found to be located in the perinuclear and cytoplasmic areas of A549 cells. The distribution pattern of metals from ambient particles showed that distributions of the metals in A549 cells were not uniform and followed the pattern Cu > Zn > Fe > Ni, suggesting that Cu was absorbed by A549 cells more easily than the other metals.ConclusionsMetal nanoparticles oxides and UFPs at low concentration could damage to cells, but the manufactured metal oxide nanoparticles are not highly toxic to lung cells compared to environmental particles. The local concentration effect of heavy metals in A549 cells, as well as the induction of oxidative stress by the particles, may be responsible for the damage observed to the cells.

Size distribution of chemical elements and their source apportionment in ambient coarse, fine, and ultrafine particles in Shanghai urban summer atmosphere

Ambient coarse particles (diameter 1.8-10 microm), fine particles (diameter 0.1-1.8 microm), and ultrafine particles (diameter < 0.1 microm) in the atmosphere of the city of Shanghai were sampled during the summer of 2008 (from Aug 27 to Sep 08). Microscopic characterization of the particles was investigated by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM/EDX). Mass concentrations of Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br, Rb, Sr, and Pb in the size-resolved particles were quantified by using synchrotron radiation X-ray fluorescence (SRXRF). Source apportionment of the chemical elements was analyzed by means of an enrichment factor method. Our results showed that the average mass concentrations of coarse particles, fine particles and ultrafine particles in the summer air were 9.38 +/- 2.18, 8.82 +/- 3.52, and 2.02 +/- 0.41 microg/m3, respectively. The mass percentage of the fine particles accounted for 51.47% in the total mass of PM10, indicating that fine particles are the major component in the Shanghai ambient particles. SEM/EDX results showed that the coarse particles were dominated by minerals, fine particles by soot aggregates and fly ashes, and ultrafine particles by soot particles and unidentified particles. SRXRF results demonstrated that crustal elements were mainly distributed in the coarse particles, while heavy metals were in higher proportions in the fine particles. Source apportionment revealed that Si, K, Ca, Fe, Mn, Rb, and Sr were from crustal sources, and S, Cl, Cu, Zn, As, Se, Br, and Pb from anthropogenic sources. Levels of P, V, Cr, and Ni in particles might be contributed from multi-sources, and need further investigation.

Study on coal recovery technology from waste fine Chinese coals by a vegetable oil agglomeration process

Nowadays, coal production increases continuously due to an increase in mechanization in coal mining and demand in its related fields of application worldwide. Coal production in China is especially an increasing trend and a large amount of waste fine coal is produced. Waste fine coals usually contain large amounts of ash and inorganic sulfur due to non-selective coal mining of the coal. Therefore, waste fine coals are available as a resource and cause spontaneous combustion leading in turn to air pollution because of their coal contents and small particle sizes which increases the surface area liable to be wet and oxidized, and the disposal site of waste fine coals cause land occupation, soil pollution and water contamination. In this study, a vegetable oil agglomeration process was performed for coal recovery from Chongqing Nantong waste fine coals in China. The oil agglomeration process has been used to mineral oil of exhaustible resource. Therefore, in this study, several kinds of vegetable oils are selected as oil agglutinative agents because the vegetable oils which are renewable, available and less-pollutant energy resources. The effects of the parameters including particle sizes, agitation conditions, chemical structure and viscosity of vegetable oils were investigated based on the combustible matter recovery, ash reduction and efficiency index. It was concluded that particle sizes of waste fine coal, agitation rate and agitation time will influence on the recovery efficiency of combustible matter from its original waste coal by the colza oil agglomeration. Furthermore, a wide range of vegetable oil alteration grades including prepared waste vegetable oil samples and therefore, of oil properties, such as chemical

Size distribution and sources of 37 toxic species of particulate polycyclic aromatic hydrocarbons during summer and winter in Baoshan suburban area of Shanghai, China

The objectives of this study were to assess the size-segregated distribution and sources of 37 different species of particulate polycyclic aromatic hydrocarbons (PAHs) in a suburban area of Shanghai metropolitan City, China. The ambient particulate sampling was carried out on the rooftop of a five-stories building in Baoshan campus of Shanghai University. An Andersen high-volume air sampler was employed to collect ambient size-segregated particulate matter during summer of August to September and winter of November to December 2015. The high toxic PAHs were determined by a gas chromatography mass spectrometry. The concentrations of total PAHs in suspended particulate matter (SPM) and PM1.1 (suspended particulate matter below 1.1μm in diameter) in the suburban area of Shanghai were 4.58-14.5ng/m(3) and 1.82-8.56ng/m(3), respectively in summer, and 43.6-160ng/m(3) and 23.2-121ng/m(3), separately in winter. 1,8-Naphthalic anhydride (1,8-NA) showed the highest concentration among 37 different species of PAHs in the suburban area of Shanghai. The concentrations of high molecular PAHs (e.g. 5-6 ring PAHs) followed a nearly unimodal size distribution with the highest peaks in PM1.1. The diagnostic ration qualitatively indicated that PAHs in SPM of Shanghai were mainly derived from motor-vehicle or petroleum combustion in summer and from coal and biomass combustion in winter. According to the calculated toxicity equivalency factors based on the methods of Nisbet and Lagoy and the potency equivalency factors (PEF) recommended by U.S. EPA, the highest contributors in the total carcinogenicity of the PAHs in SPM and PM1.1 were dibenzo[a,h]pyrene (46.2% and 45.0% in summer), benzo[a]pyrene (44.4% and 43.8% in winter) and benz[j]aceanthrylene (80.2% and 83.1% in summer and 83.1% and 84.0% in winter), respectively. Therefore, benzo[a]pyrene seemed to be a lower contributor than other carcinogenic PAHs.

Arbuscular Mycorrhizal Association for Growth and Nutrients Assimilation of Pharagmites japonica and Polygonum cuspidatum Plants Growing on River Bank Soil

ABSTRACT Effects of arbuscular mycorrhizal fungi (AMF) on the growth, nutrient absorption, and inoculation effectiveness of AMF on pioneer plants Pharagmites japonica (C4) and Polygonum cuspidatum (C3) were evaluated by performing a pot experiment in a greenhouse at Saitama University, Japan. AMF spores were collected from the commercial product, Serakinkon. The average colonization levels of P. japonica and P. cuspidatum were 24–33% and 0.2–0.5% respectively and no colonization was found in sterilized soil treatment. AMF colonization increased the plant dry mass, phosphorus (P), and nitrogen (N) concentrations of P. japonica’s roots, stems, and leaves when AMF applied with natural and sterilized soil compared with only sterilized and natural soil. This was a significant effect for N-loss minimization from soil. Maximum value showed when P. japonica was grown with natural soil in combination with AMF whereas P. cuspidatum showed very less or a negative response to AMF colonization in all cases.

Liquefaction Processes And Characterization Of Liquefied Products From Waste Woody Materials In Different Acidic Catalysts

The liquefaction process is one of the promising techniques for effective utilization of woody biomass, for the lignocelluloses can be converted to liquid reactive material, as eco-polymeric materials. Japanese cedar (Cryptomeria Japonica), as an abundant waste softwood material, was selected and used in our wood liquefaction experiment. In order to investigate the basic characteristics and potentially harmful metal contents, the composition and metal elements of waste woody samples had been determined, and based on the methods of Japanese Industrial Standard (JIS) and by an ICP-AES, separately. Then the waste woody samples were liquefied by a phenol wood liquefaction according to the orthogonal test L9 (3 4 ), in order to obtain relatively less residue by different reaction conditions. It is thought that sulfuric acid plays an important role in retarding the condensation reaction during the acid-catalyzed phenol liquefaction because of the dehydration, and it can be summarized that the most influential factors of the wood liquefaction conditions were obtained within the setting ranges on four factors and three levels by using the orthogonal tests. In the acidic catalyst comparison experiment, as a result, when using concentrated sulfuric acid as the strong acidic catalyst, the minimum of residual content had reached 9.71%. According to these experimental results, the new liquefied samples

Behavior Of Suspended Particulate Matter Emitted From Combustion Of Agricultural Residue Biomass Under Different Temperatures

There are large quantities of waste rice husk and straw estimated around 3.9 million tons as biomass waste every year in Japan. Air pollutants emitted from exhaust gases of rice husk incineration lead to environmental damage, not only because of the influence on global environment and climate, when released into the atmosphere, but also on human health due to local air pollution. Therefore, it is necessary to effectively utilize waste rice husk and straw to reduce air pollutants. In recent years, there has been an increasing demand on the utilization of unused biomass instead of fossil oil fuel in combustors for farminggreenhouses heating during the winter season. The increasing demand will increase the running costs. In general, since these combustors are small in size, there is a lack of regulations or laws (e.g. The Air Pollution Control Act and The Waste Disposal and Public Cleaning Law) in operation for their air pollution control. So far, small size combustors are characterized by their simplicity of structure and low costs. However, they emit visible black carbon (elemental carbon) due to their poor combustion performance. In this study, we investigated that the possibility of the substitution of fossil fuel by waste rice husk and rice straw in laboratory model combustion experiments. We evaluated the emission behavior of harmful air pollutants emitted from rice husk and straw combustion by measuring carbonaceous and ionic composition of suspended particulate matter in the exhaust gases. From the analytical results we found that particulate mass concentrations reduced substantially at high temperature combustion. From the results of our study, it can be suggested that stable combustion performance under suitable conditions

Role of arbuscular mycorrhizal fungi on the performance of floodplain Phragmites japonica under nutrient stress condition

A pot experiment was conducted to evaluate the potential effects of arbuscular mycorrhizal fungi (AMF) on growth, nutrient uptake, and inoculation effectiveness on Phragmites japonica. Spores of AMF strains (Gigaspora margarita Becker & Hall) were collected from the commercial product ‘Serakinkon’. Four treatments, namely, natural soil (NS), natural soil inoculated by AM fungi, sterilised soil (SS) inoculated by AM fungi, and SS without AM fungi inoculation were selected to determine the effects of applied and indigenous AMF on P. japonica. The average colonisation level of P. japonica was 24–33%, whereas no colonisation was found in the SS. AMF colonisation increased the chlorophyll content (r = 0.84, p < .01), plant dry mass (r = 0.89, p < .01), and N, P, K, Mg, and Fe concentration of the plants roots, stems, and leaves when AMF was applied with natural and SS. In all cases, maximum values were found when the plants were applied with NS in combination with AMF, but Ca concentration decreased as the colonisation level increased. Mn concentration decreased in the roots, but increased in the leaves. Cu concentration was not significantly affected by treatments. N-loss minimisation from the soil was significant when the colonisation level was high.

Characterization of suspended particulate matter emitted from waste rice husk as biomass fuel under different combustion conditions

There are large quantities of waste rice husk, e.g. around 3 million tons are estimated as biomass waste every year in Japan. Air pollutants emitted from exhaust gases of rice husk incineration lead to very important environmental damage, not only because of the influence on global environment and climate, when released into the atmosphere, but also on human health due to local air pollution. Therefore, it is necessary to effectively utilize waste rice husk and to reduce air pollutants. In recent years, there is an increasing demand on the utilization of unused biomass instead of fossil oil fuel in combustors for farminggreenhouses heating during the winter season. This increase in the demand will increase the running costs. In general, since these combustors are small in size, there is lack of regulations or laws (e.g. the air pollution control act and the waste disposal and public cleaning law) in operation for their air pollution control. So far, small size combustors are characterized by their simplicity of structure and the low costs; therefore, they emit visible black carbon (elemental carbon) due to their poor combustion performance. In this study, we investigated if fossil fuel can be substituted by waste rice husk in laboratory model combustion experiments. We evaluated the emission behavior of harmful air pollutants emitted from rice husk combustion by measuring carbonaceous and ionic composition of suspended particulate matter in the exhaust gases. From the analytical results we found that particulate mass concentrations can be reduced substantially at high temperature combustion. Fine particle size distribution is different with combustion conditions (e.g. smoldering combustion, flaming combustion). Ionic composition is mainly

Emission Control of SO2 by Dry Coal-Cleaning and Bio-Briquette Technology

In China, the large amount of sulfur dioxide and dust discharged from the combustion of low-grade raw coal causes severe air pollution and acid rain. Therefore, the need to control the emission of such pollutants is urgent. It is well known that wet coal-cleaning technology is used to prepare clean coal from low-grade raw coal containing large amounts of sulfur and ash. However, this technology is not used in areas where water is scarce or severely polluted, because of the high cost of treating the wastewater. In an attempt to overcome this limitation, we studied an integrated technology, which combines dry coal-cleaning and bio-briquetting technologies, to prepare clean coal from low-grade raw coal. In the dry coal-cleaning method, refined coal was separated from ash and other minerals containing inorganic sulfur as pyrite by means of the differences in their electrostatic character. Most of the sulfur left in the refined coal was organic sulfur. The residual ash was fixed in combustion ashes of bio-briquettes made from coal, biomass, and slaked lime (Ca/S mole ratio =2) under pressure. By combining these two technologies, we were able to decrease the emission of sulfur dioxide and ash by 70≈90% compared to the combustion of raw coal.