干旱区城市邻苯二甲酸酯湿沉降及其环境意义

本文以新疆昌吉市为研究区,选择2012年6月至2012年12月期间的12场次降水进行采集,利用气相色谱法测定样品中主要PAEs,以对干旱区城市大气邻苯二甲酸脂湿沉降进行初步探讨。研究表明:大气湿沉降中DBP的含量最高,其次是DEHP,DMP与DEP含量较低;DEHP、DBP、DMP以及DEP在雨沉降中平均含量分别为0.10(0.07~0.13)mg/L、0.32(0.03~0.93)mg/L、0.004(未检出~0.02)mg/L、0.006(未检出~0.05)mg/L;在雪沉降中平均含量分别为0.04(0.008~0.13)mg/L、0.13(0.05~0.40)mg/L、0.002(未检出~0.005)mg/L、0.08(未检出~0.04)mg/L。昌吉市湿沉降中PAEs含量远超出《地表水环境质量标准》,也超出了城市生活污水与工业污水,说明其存在较大的环境风险。PAEs的湿沉降具有较为明显的季节变化,雪沉降(冬季)中PAEs含量普遍低于雨沉降(其他季节),人类在室外生产、生活活动的季节变化及气温对PAE挥发的影响是主要原因。计算结果显示,大气湿沉降每年向昌吉市城区地表环境输入DBP、DEHP、DMP、DEP分别达到1994.28、652.69、27.14、57.86kg,输入的上述4种PAEs总和达到2731.97kg。

Study on Wet Deposition and Environmental Significance of PAEs in Urban Arid Areas

In order to study the wet deposition of PAEs in atmosphere of arid areas, Changji City was cited as an example, 12 times precipitation samples collected in the period from June 2012 to December 2012 were analyzed by gas chromatography. The results showed that the contents of DBP are highest in Changji City wet deposition atmosphere samples, followed by DEHP, and DMP and DEP are lowest. The average values for DEHP, DBP, DMP and DEP in rain deposition are 0.10 (0.07~0.13) mg/L, 0.32 (0.03~0.93) mg/L, 0.004 (undetected~0.02) mg/L, 0.006 (undetected~0.05) mg/L, respectively; the average values for DEHP, DBP, DMP and DEP in snow deposition are 0.04 (0.008~0.13) mg/L, 0.13 (0.05~0.40) mg/L, 0.002(undetected~0.005) mg/L, 0.008(undetected~0.04) mg/L,respectively. There exists a high environmental risk, because the contents of PAEs in Changji City wet deposition far exceed the standard of surface water environment quality, and also exceed the standard of city life sewage and industrial wastewater. The wet deposition shows a significant seasonal variation, and PAEs contents in snow precipitation (winter) are generally lower than those in rain precipitation (other seasons). The seasonal variation of people production, outside living activities and air temperature are the main factors affecting PAEs volatilization. The calculation results indicated that total PAEs to be input into Changji City earth surface come up to 2731.97 kg every year, among which, DBP, DEHP, DMP, DEP are 1994.28 kg, 652.69 kg, 27.14 kg and 57.86 kg, respectively.