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Wu J.,Sichuan Agricultural University | Wu J.,University of Sichuan | Tang Y.,University of Sichuan | Li Z.,Nanchong Environmental Monitoring Center | Yang G.,Sichuan Agricultural University
Yingyong Jichu yu Gongcheng Kexue Xuebao/Journal of Basic Science and Engineering | Year: 2011

Compound contamination of heavy metals is a major type of soil pollution. Pot experiment was carried out to investigate the tolerance of cordate houttuynia (Houttuynia cordata Thunb.) to lead(Pb) and Zinc(Zn). Its potential capacity for phytoremediation of heavy metal contaminated soils was also investigate in current work. Results showed that Pb concentration in roots, stems and leaves of cordate houttuynia increased significantly as the increasing of Pb addition in soil. The Pb concentration distribution in cordate houttuynia was in the sequence of stems>roots>leaves. The biological transfer factor of stem was higher than 1, and higher bioaccumulation factors could also be observed in both stems and leaves. These results indicated that cordate houttuynia had a strong capability to translocate and accumulate Pb. As Zn addition increased in soil, the Zn concentration in roots increased significantly. However, it increased initially and then decreased sharply in stems and leaves. Moreover, the biological transfer factor for stems and leaves, and the bioaccumulation factors for stems increased firstly and then decreased, but the bioaccumulation factor for leaves decreased gradually. The antagonistic effect of Zn on Pb accumulation was observed. The Zn accumulation was enhanced firstly with the increasing of Pb addition. However, it could be inhibited when the Pb addition further increased beyond 1000mg/kg. Different ratios of Pb and Zn addition had different interactive effects on the growth and heavy metal accumulation of cordate houttuynia. Based on the higher tolerance and bioaccumulation capability of cordate houttuynia to Pb, it was possible to select cordate houttuynia as a phytoremediator for Pb contaminated soil or Pb-Zn compound polluted soil with a low Zn concentration. Source


Zhou H.,China West Normal University | Zhou H.,Sichuan Kaile Detection Technology Co. | Li Y.,China West Normal University | Liu H.,China West Normal University | And 5 more authors.
Environmental Engineering Research | Year: 2015

The PM10, SO2 and NO2 mass concentrations were obtained over five years from monitoring stations across Nanchong, a southwest city in China. Changes in urban air quality over time, as well as the factors influencing that change, were evaluated based on air pollutant concentrations, the Air Pollution Index (API), and the Comprehensive Pollution Index (P). The results showed that the total annual mean PM10, SO2 and NO2 concentrations over the five years studied were 61.1±1.1, 45.0±3.9 and 34.9±4.9 μg·m-3, respectively. The annual mean concentrations displayed a generally decreasing trend; lower than the annual mean second-level air quality limit. Meanwhile, the annual mean API values were in a small range of 52-53, the air quality levels were gradeⅡ, and P values were 1.06-1.21 less than the slight level (P ≤ 1.31). Total monthly mean PM10, SO2, NO2 concentrations, and API and P values were consistently higher in winter and spring than during autumn and summer. The results of a correlation analysis showed that temperature and pressure were the major meteorological factors influencing pollution levels. Pollution sources included industrial coal and straw burning, automobiles exhaust and road dust, fireworks, and dust storms. © 2015 Korean Society of Environmental Engineers. Source

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