外源含硫化合物对土壤挥发性有机硫化合物交换通量的影响

通过静态箱采样和Entech7100预浓缩仪-GC-MS分析了半胱氨酸、硫化钠和硫酸钠对土壤吸收或释放羰基硫（COS）、二甲基硫醚（DMS）、二硫化碳（CS2）和二甲二硫醚（DMDS）等4种挥发性有机硫化合物（VOSCs）的影响.结果表明,添加半胱氨酸后,土壤由COS和CS2汇转变为源,DMS和DMDS通量显著增加,且...

Influence of Exogenous Sulfur-containing Compounds on the Exchange Fluxes of Volatile Organic Sulfur Compounds

The influences of cysteine, sodium sulfide (Na₂S) and sodium sulfate (Na₂SO₄) on the soil-air exchange fluxes of volatile organic sulfur compounds (VOSCs), including carbonyl sulfide (COS), dimethyl sulfide (DMS), carbon disulfide (CS₂) and dimethyl disulfide (DMDS), were studied employing static chamber enclosure followed by laboratory determination using an Entech 7100 preconcentrator coupled with an Agilent 5973 GC-MSD. The results showed that after the addition of cysteine, the soil for the exchange fluxes of COS and CS₂ shifted to be the source from sink and the emissions of DMS and DMDS increased significant. The emission amount of DMS and CS₂ accounted for 89.2% to the total VOSCs after the addition of cysteine, implying that cysteine is an important precursor for DMS and CS₂ in the soil. The amount of DMDS accounted for 93.2% to the total sulfur from the soil after addition of Na₂S, indicating that Na₂S is a key precursor for DMDS. No significant difference of VOSCs fluxes was found between the controlled soil and the soil with addition of Na₂SO₄, suggesting Na₂SO₄ was not the direct precursor for VOSCs in soil. VOSCs exchange rates reached the maximum at 6 to 8 days after addition of cysteine. As for addition of Na₂S, the maximal emission rates of different VOSCs appeared at different dates, and the dates differed significantly from those after addition of cysteine, implying that the formation process of VOSCs from the soil with addition of Na₂S was more complex and different from the soil with addition of cysteine.