Distribution and Leaching Behavior of Organophosphorus and Brominated Flame Retardants in Soil in Chengdu

A total of 29 surface farmland soil samples were collected to investigate the spatial distribution and composition characteristics of 13 organophosphorus flame retardants (OPFRs), 11 PBDEs, and 8 novel brominated flame retardants (NBFRs) in Chengdu, China. The OPFRs were widely existed in the farmland soil, with concentrations ranging from 2.92 to 160 ng/g dry weight (dw). BDE-209 was the main PBDEs congener in the surface farmland soil accounted for 90%, with concentrations ranging from n.d. to 50.4 ng/g dw. In the case of NBFRs, only TBB and BTBPE were detected in the farmland soil from rural area of Chengdu. No significant difference was found in the OPFRs concentrations among Xindu, Longquan, Shuangliu, Wenjiang, and Pixian districts (<i>p</i> &gt; 0.05), but the maximum concentration of OPFRs from Xindu district was higher than those in other studied areas, which might be resulted in furniture production in this area. Leaching experiment showed most investigated OPFRs levels in two soils decreased with the increasing of soil depth. There was no obvious difference in leaching behavior of the OPFRs in laterite and loess, but higher content of DOM prevented the OPFRs from leaching out in soil, and TCEP have more mobility than TCPP, which might have more potential pollute groundwater.本研究共采集29个表层农田土壤样品，旨在探究中国成都市农田土壤中13种有机磷阻燃剂（organophosphorus flame retardants, OPFRs）、11种多溴联苯醚（PBDEs）以及8种新型溴代阻燃剂（novel brominated flame retardants, NBFRs）的空间分布与组成特征。有机磷阻燃剂在农田土壤中广泛检出，浓度范围为2.92~160 ng/g干重（dry weight, dw）。BDE-209为表层农田土壤中主要的多溴联苯醚同系物，占总多溴联苯醚的90%，浓度范围为未检出（n.d.）至50.4 ng/g干重。针对新型溴代阻燃剂，成都农村地区农田土壤中仅检出TBB与BTBPE。新都区、龙泉驿区、双流区、温江区与郫都区的农田土壤有机磷阻燃剂浓度无显著统计学差异（p>0.05），但新都区的有机磷阻燃剂最高浓度高于其余研究区域，该现象可能与该区域的家具生产活动相关。淋溶实验结果表明，两种供试土壤中的多数目标有机磷阻燃剂含量随土层深度增加而降低。红壤与黄土中有机磷阻燃剂的淋溶行为无显著差异，但土壤中较高的溶解性有机质（dissolved organic matter, DOM）含量会阻碍有机磷阻燃剂的淋溶析出；且TCEP的迁移性强于TCPP，其对地下水的污染潜在风险更高。