Singh Neera, Kookana Rai S
Division of Agricultural Chemicals, Indian Agricultural Research Institute, New Delhi, India.
J Environ Sci Health B. 2009 Mar;44(3):214-9. doi: 10.1080/03601230902728112.
The sorption of carbaryl (1-naphthyl methyl carbamate) and ethion [O,O,O',O'-tetraethyl S,S'-methylene bis(phosphorodithioate)] was studied in whole soils as well as after treatment of soil with 2% hydrofluoric acid (HF) to remove paramagnetic materials and to oxidize most forms of labile carbon by photo-oxidation with high energy (UV) on < 53 microm fractions. The sorption coefficient (K(d)) values for carbaryl and ethion in soils did not follow the order of their organic carbon (OC) content, and specially their char content However, the K(oc) values in < 53 microm fractions after hydrofluoric acid/photo-oxidation with high energy (hydrofluoric acid/ultraviolet; HF/UV) treatment were found to be much higher than those in bulk untreated soils. The effect of organic matter chemistry was determined by correlating K(oc) values of contaminants in bulk soils or 53 microm fractions against sample aromaticity. A poor correlation of K(oc) in bulk soil and aromatic C values of both carbaryl and ethion was observed. However, the correlation between the K(oc) and the aromatic fraction of C after the HF/UV treatment improved significantly, reflecting the contribution of char fraction of carbon in soils towards sorption of pesticides. The increase in sorption after HF/UV treatment suggested that the sorption potential of biochars, which are expected to contribute significantly to contaminant sorption due to their high surface area, can remain masked by the organo-mineral interactions of char in whole soils. This has implications for the modification of surfaces of the freshly applied biochars in soils due to organo-mineral interactions.
研究了西维因（1-萘基甲基氨基甲酸酯）和乙硫磷[O,O,O',O'-四乙基S,S'-亚甲基双（二硫代磷酸酯）]在原状土壤中的吸附情况，以及用2%氢氟酸（HF）处理土壤以去除顺磁性物质，并通过高能（紫外线）光氧化<53微米级分中的大部分不稳定碳形式后的吸附情况。西维因和乙硫磷在土壤中的吸附系数（K(d)）值并不遵循其有机碳（OC）含量的顺序，特别是其炭含量的顺序。然而，经氢氟酸/高能光氧化（氢氟酸/紫外线；HF/UV）处理后，<53微米级分中的K(oc)值远高于未处理的原状土壤中的K(oc)值。通过将原状土壤或<53微米级分中污染物的K(oc)值与样品芳香性相关联，确定了有机质化学的影响。观察到原状土壤中K(oc)与西维因和乙硫磷的芳香碳值之间的相关性较差。然而，HF/UV处理后K(oc)与碳的芳香级分之间的相关性显著改善，反映了土壤中炭部分的碳对农药吸附的贡献。HF/UV处理后吸附的增加表明，由于其高表面积而有望对污染物吸附做出重大贡献的生物炭的吸附潜力，可能会被原状土壤中炭的有机-矿物相互作用所掩盖。这对土壤中新鲜施用的生物炭由于有机-矿物相互作用而导致的表面改性具有重要意义。
