Assessing the chemical and biological accessibility of the herbicide isoproturon in soil amended with biochar
Assessing the chemical and biological accessibility of the herbicide isoproturon in soil amended with biochar
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DOI：
10.1016/j.chemosphere.2012.02.066
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发表时间：
2012-06-01
期刊：
影响因子：
8.8
通讯作者：
Bending, Gary
中科院分区：
文献类型：
--
作者：
Sopena, Fatima;Semple, Kirk;Bending, Gary
目前，人们对使用生物炭（BC）作为土壤改良剂来固碳以减缓气候变化有相当大的兴趣。然而，将BC添加到农业土壤中对农药环境命运的影响仍不清楚。特别是，生物炭对化合物解吸行为的影响知之甚少。本研究以异丙隆（伊普）为除草剂，考察了BC对农药化学和生物可及性的影响。土壤修正与1%和2%BC表现出增强的吸附，较慢的解吸，并减少生物降解的伊普。添加0.1%BC对伊普的吸附、解吸和生物降解没有影响。然而，C-14-伊普的矿化被所有BC浓度降低，在BC浓度为0.1%、1%和2%时分别降低13.6%、40.1%和49.8%。此外，毒性代谢物4-异丙基苯胺与完整伊普的比率通过较高的BC浓度显著降低。羟丙基-β-环糊精（HPCD）提取物被用来估计在BC-修正土壤中的伊普生物可利用性。对于所有BC改良的土壤，HPCD提取的C-14-伊普与伊普解吸率（%）（r（2）= 0.8518，p < 0.01）以及C-14-伊普矿化率（%）（r（2）= 0.733; p < 0.01）之间均存在显著相关性。这项研究清楚地表明，在BC的存在下，解吸是如何密切相关的土著土壤微生物的农药生物降解。在农业土壤中施用溴化碳会影响农药的持久性及其降解产物的命运。这对农药的有效性以及土壤中污染物的螯合具有重要意义。(C)2012爱思唯尔有限公司保留所有权利。
There is considerable current interest in using biochar (BC) as a soil amendment to sequester carbon to mitigate climate change. However, the implications of adding BC to agricultural soil for the environmental fate of pesticides remain unclear. In particular, the effect of biochars on desorption behavior of compounds is poorly understood. This study examined the influence of BC on pesticide chemical and biological accessibility using the herbicide isoproturon (IPU). Soils amended with 1% and 2% BC showed enhanced sorption, slower desorption, and reduced biodegradation of IPU. Addition of 0.1% BC had no effect on sorption, desorption or biodegradation of IPU. However, the mineralization of C-14-IPU was reduced by all BC concentrations, reducing by 13.6%, 40.1% and 49.8% at BC concentrations of 0.1%, 1% and 2% respectively. Further, the ratio of the toxic metabolite 4-isopropyl-aniline to intact IPU was substantially reduced by higher BC concentrations. Hydroxypropyl-beta-cyclodextrin (HPCD) extractions were used to estimate the IPU bioaccessibility in the BC-amended soil. Significant correlations were found between HPCD-extracted C-14-IPU and the IPU desorbed (%) (r(2) = 0.8518, p < 0.01), and also the C-14-IPU mineralized (%) (r(2) = 0.733; p < 0.01) for all BC-amended soils. This study clearly demonstrates how desorption in the presence of BC is intimately related to pesticide biodegradation by the indigenous soil microbiota. BC application to agricultural soils can affect the persistence of pesticides as well as the fate of their degradation products. This has important implications for the effectiveness of pesticides as well as the sequestration of contaminants in soils. (C) 2012 Elsevier Ltd. All rights reserved.