Qi-She Yan

Nankai University, Tianjin, Tianjin Shi, China

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Publications (2)7.39 Total impact

  • Hong-wen Sun, Qi-she Yan
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    ABSTRACT: Interactions of hydrophobic organic compounds (HOCs) with soil organic matter (SOM) determine their combination state in soils, and therefore strongly influence their mobility, bioavailability, and chemical reactivity. Contact time (aging) of an HOC in soil also strongly influences its combination state and environmental fate. We studied Fenton oxidation of pyrene in three different soils to reveal the influences of SOM, contact time, and combination state on the efficiency of vigorous chemical reactions. Pyrene degradation efficiency depended strongly on the dose of oxidant (H(2)O(2)) and catalyst (Fe(2+)); the greatest degradation was achieved at an oxidant to catalyst molar ratio of 10:1. Pyrene degradation differed among the three soils, ranging from 65.4% to 88.9%. Pyrene degradation efficiency decreased with increasing SOM content, and the aromatic carbon content in SOM was the key parameter. We hypothesize that pyrene molecules that combine with the compact net structure of aromatic SOM are less accessible to Fenton oxidation. Furthermore, pyrene degradation efficiency decreased considerably after aged for 30 days, but further aging to 60 and 180 days did not significantly change degradation efficiency. The Fenton oxidation efficiency of pyrene in both unaged and aged soils was greater than the corresponding desorption rate during the same period, perhaps because Fenton reaction can make pyrene more accessible to the oxidant through the enhancement of HOCs' desorption by generating reductant species or by destroying SOM through oxidation.
    Journal of Environmental Management 09/2008; 88(3):556-63. · 3.06 Impact Factor
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    Hong-Wen Sun, Qi-She Yan
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    ABSTRACT: The influences of Fenton oxidation on the content and composition of soil organic matter (SOM) and the consequent change of its sorption and desorption of pyrene were investigated using three soil samples. The results showed that both the content and the composition of the SOM changed, with total SOM content decreasing. The content of humic acid (HA) was reduced, while the content of humin did not change significantly, however the content of fulvic acid (FA) had a tendency to increase. Correlation analysis of soil-water distribution coefficient (K(d)) and different parts of the SOM reveals that humin and HA are the key factors controlling the sorption of pyrene. Organic carbon normalized K(d) (K(OC)) varied to different extents after Fenton oxidation due to the change of SOM composition. The reduction of K(OC) is significant in Soils 1 and 2 where large part of HA was reduced to FA, whose sorption ability is low. The change of K(OC) by oxidation in Soil 3 is not so significant due to that the percentage of humin and HA in Soil 3 did not change greatly after oxidation. Desorption was hysteretic in all cases, and humin percentage was found to be the key factor on the extent of desorption hystersis. Oxidation made desorption more hysteretic due to the elevated proportion of humin.
    Journal of Hazardous Materials 07/2007; 144(1-2):164-70. · 4.33 Impact Factor

Publication Stats

30 Citations
7.39 Total Impact Points

Institutions

  • 2007–2008
    • Nankai University
      • College of Environmental Science and Engineering
      Tianjin, Tianjin Shi, China