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Wang S.,Tianjin Academy of Environmental science | Liu J.,Nankai University
Environmental Monitoring and Assessment | Year: 2014

In the previous study, Mirabilis jalapa L. had revealed the basic Cd hyperaccumulator characteristics, but the accumulation ability was not as strong as that of other known Cd hyperaccumulators. In order to improve the accumulation ability of this ornamental plant, the chelants were used to activate the Cd in soil. As a substitute, ethylene glycol bis(2-aminoethyl) tetraacetic acid (EGTA) was selected to testify whether it has better effectiveness and can bring lesser metal leaching risk than EDTA. The data showed that the growth of M. jalapa was inhibited, while the Cd concentration of the plant was significantly increased under the treatments containing EDTA or EGTA. The Cd translocation ability under the EGTA treatments was higher than that under the EDTA treatments. The available Cd resulted from the application of chelant EGTA to the contaminated soils can be limited to the top 5 cm, while the application of chelant EDTA to the contaminated soils can be limited to the top 10 cm. In a word, EGTA showed better effectiveness than EDTA in enhancing Cd phytoextraction of M. jalapa. As an ornamental plant, M. jalapa has the potential to be used for phytoextraction of Cd-contaminated soils and it can beautify the environment at the same time. © 2013 Springer Science+Business Media Dordrecht.

Li W.,Nankai University | Li W.,Tianjin Academy of Environmental science | Peng Y.,Liaoning Provincial Environmental Monitoring Center | Shi J.,Nankai University | And 3 more authors.
Atmospheric Environment | Year: 2011

In this study, concentrations of polycyclic aromatic hydrocarbons (PAHs) associated with PM 10 were measured to examine the status, characteristics and sources of atmospheric PAH pollution in the industrial Northeast Region of China. Mean concentrations of total PAHs were 65.5, 40.0, 73.0 and 436.7 ng m -3 in the four seasons respectively. The calculated BaPeq concentrations in winter all exceeded the national standard, imposing serious PAH exposure risk. PAH concentrations varied between the cities, but PAH concentrations in different functional areas within a city did not show significant difference. In general, particulate PAH profiles were dominated by 4- and 5-ring compounds. Elevated proportions of 3-ring PAHs and 5-ring PAHs were found in winter and in summer respectively. Diagnostic ratios and principal component analysis (PCA) were used to identify potential sources of PAHs. Coal combustion activities were the main contributors of particle-associated PAHs in this region. © 2011 Elsevier Ltd. All rights reserved.

Tang J.,Nankai University | Lu X.,Tianjin Academy of Environmental science | Sun Q.,Nankai University | Zhu W.,Nankai University
Agriculture, Ecosystems and Environment | Year: 2012

In this paper, aging process of petroleum-contaminated soil was characterized during 210. d of attenuation under different conditions: clean soil spiked with petroleum (Run 1), clean soil spiked with petroleum and humic acid (Run 2), quartz sand spiked with petroleum (Run 3) and petroleum-contaminated saline soil from an oil field (Run 4). An initial increase of pH was found before 60. d of aging. Total petroleum hydrocarbon (TPH) content decreased with the process of aging and the degradation rates for the 4 runs were 61%, 60%, 24% and 20% after 210. d of aging, respectively. The saturated fraction of petroleum hydrocarbons was most degraded in Run 1 in clean soil; while addition of humic acid enhanced the degradation of aromatic fraction and asphaltene and polar fraction. Addition of TPH in soil resulted in the increase of the dehydrogenase activity at the initial period of aging. A significant negative correlation was found between bacteria count and TPH content during aging process and fungi number was only increased at certain time of aging. The biological toxicity increased at the middle of aging process of 30-60. d as determined by plant growth and luminescent bacteria experiment. The result suggested that proper regulation on the influencing factors such as particle size and salinity was important for the management of contaminated soils and could enhance the natural attenuation of the petroleum pollutants. © 2012 Elsevier B.V.

Gu Z.-Y.,Nankai University | Wang G.,Tianjin Academy of Environmental science | Yan X.-P.,Nankai University
Analytical Chemistry | Year: 2010

Metal-organic frameworks (MOFs) are one kind of highly porous crystalline materials, which are constructed by metal-containing inorganic nodes and organic linkers. With large surface area and high thermal stability, MOFs have great potential as sorbents for the preconcentration of trace analytes. However, such application of MOFs to the analysis of real samples has not been reported before. Here we report the utilization of MOF-5 as sorbent for in-field sampling and preconcentration of atmospheric formaldehyde before thermal desorption (TD) GC/MS (TD-GC/ MS) determination without the need for any chemical derivatization. MOF-5 gave a 53 and 73 times better concentration effect than Tenax TA (organic polymers) and Carbograph 1TD (graphitized carbon black), respectively, for TD-GC/MS determination of formaldehyde. MOF-5 showed good performance for in-field sampling and preconcentration of formaldehyde from air samples with a relative humidity less than 45%. The collected formaldehyde on MOF-5 sorbent was stable for at least 72 h at room temperature before TD-GC/MS analysis. One tube packed with 300 mg of MOF-5 lasted 200 cycles of adsorption/TD without significant loss of collection ef-ficiency. The breakthrough volume of such a tube was 1.2 L of 28.35 mg m-3 formaldehyde at a sampling flow rate of 100 mL min-1. The use of MOF-5 for in-field sampling and preconcentration in combination with TD-GC/MS for the determination of formaldehyde offered a linear range covering 3 orders of magnitude, and a detection limit of 0.6 μ g m-3. The precision for six replicate cycles of in-field sampling and preconcentration for TD-GC/MS determination using one 300 mg MOF-5 packed tube ranged from 2.8% to 5.3%. The tube-to-tube reproducibility of three MOF-5 tubes prepared in parallel was 7.7%. The developed method was applied to analysis of local indoor and outdoor air samples for formaldehyde and validated by the standard method TO-11A of the United States Environmental Protection Agency. The concentration of formaldehyde and the recovery of spiked formaldehyde in the air samples ranged from 12 to 48 μ gm-3, and from 93% to 107%, respectively. © 2010 American Chemical Society.

Yang Y.,Tianjin Academy of Environmental science | Chen Y.,Tianjin Academy of Environmental science | Zhang X.,Beijing Normal University | Ongley E.,Beijing Normal University | And 2 more authors.
Environmental Pollution | Year: 2012

Agricultural non-point source (NPS) pollution has been recently identified by the Chinese government as a major source of aquatic pollution. Methodologies commonly used to make basin-wide or area-wide assessments are problematic and regional distinctions have not been made relative to rainfall and runoff. Using a typical agricultural county in the Hai River basin of the North China Plan we developed methodology to estimate potential load and delivered load for crops (field crops + rice), animal production, rural living and from atmospheric N input. We use scenarios to allow for uncertainty in delivery to estimate the relative roles of different rural forms of pollution. Livestock raising is the major source of NPS pollution. Despite a 75% rural population, rural living contributes almost nothing to surface water pollution. While over-fertilization is typical, nutrient runoff from crops is low. Our results have implications for policies now under development for NPS control in China. © 2012 Elsevier Ltd. All rights reserved.

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