不同环境条件下海水中苯系物的挥发过程研究

为研究不同环境条件下海水中苯系物的挥发过程，基于吹扫捕集-气相色谱-质谱联用（PT-GC-MS）法，获取了不同模拟实验条件下海水中苯系物的挥发动力学曲线，并分析讨论了温度、风速等条件的变化对海水中苯系物挥发的影响。结果表明:不同温度、特定风速条件下海水中苯系物的挥发动力学曲线可用指数方程拟合，符合一级反应动力学模型。海水中苯系物各组分挥发随时间的变化规律基本相同，室温25℃下挥发速率明显高于4℃时；相同温度时风速提高海水中苯系物挥发速率加快。海水中苯乙烯、甲苯挥发速率稍高，二甲苯相对较低。不同实验条件下海水中苯系物的挥发速率差异明显，其大小顺序表现为室温25℃+特定风速＞室温25℃+静态挥发＞低温4℃+特定风速＞低温4℃+静态挥发。在低温4℃条件下风速对苯系物挥发的贡献程度更加显著。

Study on the volatilization process of benzene series in seawater under different environmental conditions

Simulation experiments were carried out to study the volatilization process of seven kinds of benzene series in seawater under different environmental conditions. The concentration of benzene series was determined by purging and trapping gas chromatography-mass spectrometry (PT-GC-MS). The corresponding volatilization kinetic curves, volatilization kinetic models and optimal fitting formulas were obtained. The effects of temperature and wind speed on the volatilization of benzene series were discussed. The results showed that the volatilization kinetic curves of benzene series under different temperature and specific wind speed can be fitted by exponential equation with high fitting precision, according with the first-order reaction kinetics model. The volatilization of seven kinds of benzene series in seawater with time was similar. At room temperature (25℃), the volatilization rate of each component of benzene series was obviously higher than that of 4℃. At the same temperature, the wind speed made the volatilization rate of benzene series in seawater faster. The volatilization rate of styrene and toluene in seawater was slightly high, while xylene was relatively low. Under different experimental conditions, the volatilization rate of benzene series in seawater was different. The total volatilization rate of benzene series in seawater was that:room temperature of 25℃+specific wind speed > room temperature of 25℃+ static volatilization > low temperature of 4℃+specific wind speed > low temperature of 4℃+static volatilization. The contribution of wind speed to the volatilization of benzene series was significant at low temperature of 4℃.