Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Bull Environ Contam Toxicol ; 109(5): 808-816, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36056950

RESUMEN

Heavy metals pollution in pharmaceutical industries received increasing attention. A total of 94 soil samples were collected in this study. Results showed the mean contents of Hg, Cd, As, Pb, Ni and Cu were 0.21, 0.26, 9.59, 55.06, 51.52 and 50.81 mg·kg-1, respectively. The spatial distribution of metals in topsoil largely attributed to the pharmaceutical production process. The distribution of Hg and As were related to the production of medical absorbent cotton. While Ni was related to the fuel supply of Ni-rich coal. Cr, Cu and Pb mainly distributed in the process which they were used as catalysts. The vertical migration of metals was complex in soil. To a great extent, it was related to the texture of the soil and the properties of metals in this filed. The total non-cancer and cancer human health risk were within the limits of USEPA (10-6 a-1). This demonstrated the health risks of individual's exposure to heavy metals in this factory was acceptable.


Asunto(s)
Mercurio , Metales Pesados , Contaminantes del Suelo , Humanos , Contaminantes del Suelo/análisis , Plomo , Monitoreo del Ambiente/métodos , Medición de Riesgo , Metales Pesados/análisis , Suelo , Preparaciones Farmacéuticas , China
2.
Huan Jing Ke Xue ; 42(3): 1328-1332, 2021 Mar 08.
Artículo en Chino | MEDLINE | ID: mdl-33742929

RESUMEN

Bulk gasoline terminals are an important emission source of volatile organic compounds (VOCs) in cities. Beijing started to promote the installation of oil and gas recovery devices at oil storage terminals in 2006 to reduce VOCs emissions, since then VOCs emissions from the terminals have been monitored by the municipal government every year. This paper analyzes the VOCs emission characteristics of oil storage terminals in Beijing from 2012 to 2019. We found that the VOCs import concentration was 165.3 g·m-3 in 2019 and had experienced a decline-rise-decline pattern during 2012-2019. The emission concentration was 7.3 g·m-3 in 2019 and had declined continuously during the preceding eight years. The removal efficiency of VOCs of the gas recovery devices tended to be stable and ranged from 45.5% to 100%. Although the emission concentration had decreased significantly, the removal efficiency of the recovery unit at the oil storage terminals had decreased. Therefore, this paper proposed to strengthen process management, the inspection of the service life of the oil and gas recovery units, and check and maintain records. In addition, the removal efficiency index should be included in the scope of law enforcement and "double index" requirements should be implemented This paper will provide a scientific basis for the future development of atmospheric improvement measures.

3.
Huan Jing Ke Xue ; 34(5): 1958-63, 2013 May.
Artículo en Chino | MEDLINE | ID: mdl-23914554

RESUMEN

Based on the environment monitoring data and the ambient air quality data during the period of 1997-2011 from Beijing municipal environmental monitoring center, the correlations between primary pre-cursors of acid deposition, acidic materials and precipitation in Beijing area were analyzed in detail by taking economic development and energy mix into account. These results will be helpful for assessing the performance of environment quality improvement, as well as supplying scientific supporting information to make policies for national and local environment protection authorities. The main findings included as follows: there are significant correlations between the concentrations of NO2, NOx, and SO2 in the atmosphere, which indicated that both N and S in ambient air of Beijing came from fossil fuels combustion; acidic pollutants in the air are mainly discharged from local emission sources in Beijing, while there is no obvious correlation between S and N in wet deposition and concentrations of SO2, NO2 and NOx in the atmosphere, which demonstrated that concentrations of different ions in the acid deposition were influenced by both local sources as well as the inputs from other surrounding districts. Besides, the concentration of NO3- appeared to be correlative with the amount of motor vehicles, implying that the NOx from motor vehicles have contributed the increase of NO3- concentration of substantially.


Asunto(s)
Lluvia Ácida , Contaminantes Atmosféricos/química , Monitoreo del Ambiente/métodos , Contaminantes Atmosféricos/análisis , Atmósfera/análisis , China , Dióxido de Nitrógeno/análisis , Óxidos de Nitrógeno/análisis , Dióxido de Azufre/análisis
4.
Huan Jing Ke Xue ; 32(7): 1867-73, 2011 Jul.
Artículo en Chino | MEDLINE | ID: mdl-21922802

RESUMEN

Characteristics of chemical compositions of precipitation in Beijing were analyzed. The average value of pH was 5.19 from 2005 to 2009, showing stable characteristics of acidification with precipitation. The lowest annual average pH was 4. 87 in 2008 with the highest acidification frequency of 42% and 23% in Chegongzhuang and Daxing districts respectively. The inorganic ion concentrations declined in 5a, indicating an increasing improvement of air quality in Beijing. The concentrations of NH4+ and NO3- were found to increase and contributed to the high nitrogen amount in precipitation. Different seasons have influence on composition concentrations. Generally speaking, the ion concentrations in winter were higher that that in summer. SO4(2-) was the main factor responsible for the acidification of snow in winter, SO4(2-) and NO3- had similar contributions to the acidification of precipitation in summer. It was also found that the local pollutants of SO2, NO(x) and NH3 were major contributors to the acidification of precipitation in Beijing area, local geological conditions and long-distance transfers have important effects on the neutralization of the precipitation.


Asunto(s)
Contaminantes Atmosféricos/análisis , Compuestos de Amonio Cuaternario/análisis , Lluvia/química , Nieve/química , Dióxido de Azufre/análisis , Lluvia Ácida/análisis , China , Ciudades , Monitoreo del Ambiente , Concentración de Iones de Hidrógeno , Estaciones del Año , Movimientos del Agua
5.
Guang Pu Xue Yu Guang Pu Fen Xi ; 25(9): 1496-9, 2005 Sep.
Artículo en Chino | MEDLINE | ID: mdl-16379300

RESUMEN

In this article, an ICP-OES method of simultaneous determination germanium and some major ash forming elements especially for Fe, Al, Ca, Mg, K, Na, Ti in lignites is described. An ICP-OES instrument equipped with a dual-view plasma torch and a simultaneous detector was used. This technology allows the simultaneous determination of trace elements and major components in the axial view along with in the radial view. The moderate operation condition of the instrument and analytical wavelength lack of interference from elements in the sample matrix was selected, the spectral background was automaticly eliminated. The obtained coal ashes were dissolved in mixtures of nitric acid, hydrofluoric acid and perchloric acid after coal samples were cinerated. The analytical results were in good agreement with those provided by national standard methods. The detection limit of the instrument is ranged between 0.00039-0.10 microg. x mL(-1), the precision of the method is in the range of 0.79%-2.84%, the average recovery of samples is 92.38%, the proposed method is well suitable for the determination germanium and some major ash forming elements in lignites.


Asunto(s)
Carbón Mineral/análisis , Germanio/análisis , Metales/análisis , Análisis Espectral/métodos , Aluminio/análisis , Aluminio/química , Calcio/análisis , Calcio/química , Germanio/química , Ácido Fluorhídrico/química , Hierro/análisis , Hierro/química , Magnesio/análisis , Magnesio/química , Metales/química , Ácido Nítrico/química , Percloratos/química , Potasio/análisis , Potasio/química , Reproducibilidad de los Resultados , Sodio/análisis , Sodio/química , Titanio/análisis , Titanio/química
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...