-
[show abstract]
[hide abstract]
ABSTRACT: Wei River is the major source of water for the urban residents, industrial production and agricultural activities in the central
Shaanxi plain of China. Water quality of the Wei River was determined by collecting water samples from 25 locations along
the Baoji Xi’an reach and analyzing for pH, EC, BOD5, DO, COD, F, Se, As, and Hg. Fuzzy synthetic evaluation with the entropy method for weight determination was used to assess
the water quality of the river. Results indicate that the water quality of 23 sampling sites fall into the fifth grade (bad
level), whereas two sampling sites are in the fourth grade (poor level). The comparison of this method with the typical fuzzy
synthetic evaluation shows that it is effective in water quality assessment. The assessment results indicate that the Wei
River is heavily polluted at most of the sampling locations, with mercury as the major pollutant. Strict enforcement of the
regulations for domestic and industrial wastewater discharges is vital to avoid damage to the water environment and to protect
human and ecological health.
KeywordsWater quality-Membership function-Fuzzy synthetic evaluation-Wei River
Environmental earth sciences 04/2012; 60(8):1693-1699. · 1.06 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The radiation dose and environmental health risk of radon concentration in the Lantian karst cave of China to guides and visitors
were estimated based on the continuous radon concentration monitoring. Distinct seasonal variations were observed in the radon
concentration of the air inside the cave. The maximum concentration occurred in the summer, whereas the minimum radon concentration
occurred during the winter. The annual average radon concentration in the caves investigated is slightly higher than the upper
bound of radon action level for underground space used in China and less than the upper bound of radon action level recommended
by the International Commission on Radiation Protection (ICRP) for workplaces. The annual effective dose to tour guides working
in two investigated caves varies from 4.1 to 16.5mSv, depending on different equilibrium factors together with different dose
conversion factors proposed in the literature. The annual maximum time that a tour guide or other worker can safely be inside
the cave is estimated to be 1,250 or 2,246h, depending on whether one bases this on the high or mean radon concentration,
with an equilibrium factor of one in both cases. Given the synergistic effects of smoking, tour guides who are smokers should
be in the cave only 10–20% of these hours. In all cases, the annual effective doses to visitors are well below the 1mSv maximum
suggested dose for a member of the public for 1year.
Water Air and Soil Pollution 04/2012; 198(1):307-316. · 1.63 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The concentrations of Pb, Cu, Zn, Mn, Ni, Co and Cr in street dust samples from Baoji in north-west China were measured by wavelength dispersive X-ray fluorescence spectrometry, while As and Hg in street dust samples were determined by atomic fluorescence spectrometry. Principal component analysis and cluster analysis, coupled with correlation coefficient analysis, were used to analyze the data and to identify possible sources of these heavy metals. The results indicate that street dust in Baoji has elevated heavy metal concentrations, especially Hg, Pb, Zn and Cu, which are 16-77, 7-92, 6-26 and 4-12 times the background levels in Shaanxi soil, respectively. The mean heavy metal concentrations in street dust divided by the corresponding background values of Shaanxi soil decrease in the order of Hg>Pb>Zn>Cu>Cr>As>Ni>Co>Mn>V. Three main sources of these heavy metals were identified. As, V, Pb and Co originated from nature and traffic. Cu, Zn, Hg and Mn, especially the former two, mainly derive from industry sources, as well as traffic. Cr and Ni mainly originate from soil.
Journal of hazardous materials 09/2009; 173(1-3):744-9. · 4.14 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A comprehensive study on the chemical composition of spring rainwater was carried out in Xi’an, northwestern China. All samples were analyzed for pH, electrical conductivity and main ions (SO42−, NO3−, Cl−, F−, Ca2+, Mg2+, K+, Na+ and NH4+). The pH varied from 5.14 to 7.45, with a volume-weighted mean pH of 6.64. The volume-weighted mean equivalent concentration of rainwater components followed the order SO42− > Ca2+ > NH4+ > NO3− > Cl− > Mg2+ > Na+ > F− > K+. The dominant ions, SO42−, Ca2+, NH4+ and NO3−, accounted for 88% of the total ions. Significant positive correlation of SO42−, NO3− with Ca2+ and NH4+ and the calculated neutralization factors show that Ca2+ and NH4+ are the main neutralizing constituents. Sources of major ions were assessed based on the enrichment factor. Ca2+, K+ and Mg2+ mainly originated from crust, whereas SO42− and NO3− are mostly attributable to anthropogenic sources. The major likely source of NH4+ was agricultural activities.Highlights► SO42−, Ca2+, NH4+ and NO3− are the predominant ions in the rainwater of Xi’an. ► The pH value of rainwater in Xi’an is 6.64 which neutralized by Ca2+ and NH4+. ► About 21% of acidy of Xi’an rainwater was due to NO3− and 79% due to SO42−. ► Total ions concentration shows atmospheric environment of Xi’an is severe polluted. ► The major ions of Xi’an rainwater originated from anthropogenic and soil sources.
Atmospheric Environment. 45(28):5058-5063.
-
[show abstract]
[hide abstract]
ABSTRACT: The physicochemical properties and the contamination levels of mercury and arsenic in roadway dust from Baoji, NW China were investigated using an Atomic Fluorescence Spectrophotometer. Contamination levels were assessed based on the geoaccumulation index and the enrichment factor. The results show that magnetic susceptibilities of roadway dust were higher than Holocene loess–soil of central Shaanxi Loess Plateau. The mean contents of organic matter, PM10 and PM100 were 8.8%, 21.8% and 98.6%, respectively. Mercury concentration ranged from 0.48 to 2.32 μg g−1, with a mean value of 1.11 μg g−1, 17.1 times the Chinese soil mercury background value and 37 times the Shaanxi soil mercury background value. Arsenic concentration ranged from 9.0 to 42.8 μg g−1, with a mean value of 19.8 μg g−1, 1.8 times the Chinese and Shaanxi soil arsenic background values. The geoaccumlation index and enrichment factor indicate that mercury in the dust mainly originated from anthropogenic sources with ratings of “strongly polluted” and “strongly to extremely polluted”, whereas arsenic in dust originated from both natural and anthropogenic sources, with a ratings of “moderately to strongly polluted” and “strongly polluted”. Industrial activities, such as a coal-fired power station, coke-oven plant, and cement manufacturing plant, augmented by vehicular traffic, are the anthropogenic sources of mercury and arsenic in the roadway dust.
Atmospheric Environment.
-
[show abstract]
[hide abstract]
ABSTRACT: This study investigated the influence of low molar mass organic acids, acetic acid, tartaric acid and citric acid on Cd2+ and Pb2+ adsorption by goethite and montmorillonite. The added concentrations of Cd2+ in the batch adsorption experiments were 0.04 mmol L−1 and 0.4 mmol L−1 in the goethite dispersion, and 0.4 mmol L−1 and 8.0 mmol L−1 in the montmorillonite dispersion. The added concentration of Pb2＋ was 0.4 mmol L−1 in both mineral dispersions. The adsorption of Cd2+ and Pb2+ by goethite and montmorillonite was accelerated by low acid concentrations (< 0.6–1.0 mmol L−1) but was inhibited at a concentration between 1.0 mmol L−1 and 3.0 mmol L−1. The inhibiting effect was stronger for Pb2+ than Cd2+ adsorption. The effects of the acid concentrations on Cd2+ and Pb2+ adsorption were more obvious on goethite than on montmorillonite. In the goethite system, Cd2+ adsorption was increased more by citric acid and tartaric acid than by acetic acid at low acid concentrations (< 0.6–1.0 mmol L−1). In the montmorillonite dispersions, Cd2+ adsorption was reduced more by citric acid than by acetic acid and tartaric acid at high acid concentration (> 0.6–1.0 mmol L−1). Pb2+ adsorption was influenced almost in the same manner.
Applied Clay Science.
