Measurement and modeling the gas/particle partitioning of organochlorine pesticides (OCPs) in atmosphere at low temperatures
Measurement and modeling the gas/particle partitioning of organochlorine pesticides (OCPs) in atmosphere at low temperatures
复制标题
低温大气中有机氯农药 (OCP) 的气体/颗粒分配测量和建模
DOI：
10.1016/j.scitotenv.2019.02.347
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发表时间：
2019
影响因子：
9.8
通讯作者：
Li Yi-fan
中科院分区：
文献类型：
--
作者：
Qiao Li-na;Zhang Zi-feng;Liu Li-yan;Song Wei-wei;Ma Wan-li;Zhu Ning-zheng;Li Yi-fan
有机氯农药（OCPs）的气/粒（G/P）分配已被广泛研究和文献记载，但在低温下的研究较少。本研究在中国东北地区的两个采样点，在~63 °C（−40 ~+23 °C）的宽环境温度范围内，同时采集了74对气相和颗粒相的空气样品，对其中18种OCPs进行了测定和分析，并测定了其中15种OCPs的分配系数（KP）值。应用7个模型（包括尚未用于OCPs的模型）对KP值进行了预测，并将预测结果与15种OCPs的监测数据进行了比较。结果表明，L-M-Y模型具有较好的拟合效果，与监测数据的拟合度最好（90.1 ± 11.1%的数据点在±1个对数单位内，RMSE为0.53 ± 0.18）。观察到11种OCP的预测最大分配（MP）域具有较高的辛醇-空气分配系数对数值（logKOA> 12.5），其中logKP值变为常数（−1.53），表明OCP的G/P分配处于稳定状态，但不是平衡状态。Li-Ma-Yang（L-M-Y）模型考虑了颗粒的干、湿沉积，阐明了低温下有机氯农药非平衡项的必要性。这些结果表明，L-M-Y模型对有机氯农药是有效的，特别是在低温下，该模型对描述SVOCs在大气中的分配行为具有很好的应用前景.推导了计算凝结温度TC的公式，对OCPs和其它类似SVOCs的气相和颗粒相均匀分布的情况，特别是极地地区的情况有了新的认识。
The gas/particle (G/P) partition of organochlorine pesticides (OCPs) has been widely investigated and well documented, but rare at low temperature. In this study, seventy-four pairs of air samples in two sampling sites in northeastern China at a wide ambient temperature range of ~63 °C (−40 to +23 °C) were simultaneously collected in both gaseous and particulate phases and eighteen OCPs in these samples were measured and analyzed, among which, partition quotient (KP) values for fifteen OCPs were determined. Seven models including those have never been used for OCPs were applied to predict the values ofKP, and the results were compared with the monitoring data for the fifteen OCPs. It was found out that, L-M-Y model provided advantages over the other models, with the best agreement to the monitoring data for analyzed OCPs (90.1 ± 11.1% data points within ±1 log unit, RMSE: 0.53 ± 0.18). The predicted maximum partition (MP) domain for eleven OCPs was observed with high values of their logarithm of octanol-air partition coefficient (logKOA> 12.5), where the logKPvalues become a constant (−1.53), indicating that the G/P partition of OCPs is in steady state but not the equilibrium. The Li-Ma-Yang (L-M-Y model) model, considering the wet and dry depositions of particles, elucidates the necessity of non-equilibrium term for the OCPs at low temperature. These results indicate that the L-M-Y model is valid for OCPs, which renders it highly promising for describing the partition behaviors in atmosphere for SVOCs, particularly at low temperature. An equation to calculate the condensation temperatureTCwas also derived, which gave a new understanding on the situation of chemicals with equal distribution between gaseous and particulate phases of OCPs and other similar SVOCs, especially in Polar Regions.