Pesticide Adsorptivity of Aged Particulate Matter Arising from Crop Residue Burns
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- 作者：Yaning Yang and Guangyao Sheng
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2003
- 出版时间：August 13, 2003
- 年：2003
- 卷：51
- 期：17
- 页码：5047 - 5051
- 全文大小：81K
- 年卷期：v.51,no.17(August 13, 2003)
- ISSN：1520-5118
文摘
Particulates (ashes) arising from the burning of crop residues are potentially effective adsorbents forpesticides in agricultural soils. To determine the long-term adsorptive sustainability of ashes, a wheat(Triticum aestivum L.) ash was aged under environmentally relevant conditions (in CaCl2 solution atroom temperature and pH 7) in soil extract for 1 month and in a soil (1% ash) for a period of up to12 months. The aged ash and ash-amended soil were used to sorb diuron from water. The diuronsorption was also measured in the presence of atrazine as a competing pesticide. There was noobserved microbial impact on the stability of the wheat ash in soil. All isotherms with the ash werenonlinear type-I curves, suggestive of the surface adsorption. On a unit mass basis, the ash in soilextract was 600-10000 times more effective than the soil in sorbing diuron. Adsorption of dissolvedsoil organic matter (DOM) during aging on the ash surfaces reduced the diuron adsorption by 50-60%. Surface competition from the atrazine adsorption also reduced the ash adsorption of diuron by10-30%. A total of 55-67% reduction in diuron sorption by the ash-amended soil was observed.Due to its high initial adsorptivity, the ash fraction of the aged ash-amended soil contributed >50%to the total diuron sorption. Thus, the wheat ash aged in the soil remained highly effective in adsorbingdiuron. As crop residues are frequently burned in the field, pesticides in agricultural soils may behighly immobilized due to the presence of ashes.Keywords: Sorption; pesticide; ash; aging; soil; DOM; uptake competition