Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China; Eco-Environment Protection Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China.
Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.
Sci Total Environ. 2017 Dec 1;599-600:42-49. doi: 10.1016/j.scitotenv.2017.04.148. Epub 2017 Apr 29.
This study examines a surface-pore integrated mechanism that allows soil organic matter (SOM) to influence the retention and transport of three representative pharmaceuticals and personal care products (PPCPs)-ibuprofen, carbamazepine, and bisphenol A-in agricultural soil. A series of sorption-desorption batch tests and breakthrough column experiments were conducted using manured and non-manured soils. Results show that SOM could substantially influence the environmental behaviors of PPCPs via two mechanisms: surface-coating and pore-filling. Surface-coating with molecular SOM decreases the sorption of dissociated PPCPs (e.g., ibuprofen) but increases the sorption of non-dissociated PPCPs (e.g., carbamazepine and bisphenol A), while pore-filling with colloidal SOM enhances the retention of all the PPCPs by providing nano-/micro-pores that limit diffusion. The higher retention and lower mobility of PPCPs in soil microaggregates than in bulk soils suggest that SOM content and SOM-altered soil pore structure could exert a coupled effect on PPCP retention. Differences in the elution of PPCPs with low surface tension solution (i.e., 20% ethanol) in the presence and absence of SOM indicate that PPCPs prefer to remain in SOM-filled pores. Overall, ibuprofen has a high environmental risk, whereas carbamazepine and bisphenol A could be readily retarded in agricultural soils (with a loamy clay texture). This study implies that SOM accrual (particularly pore-filling SOM) has a high potential for reducing the off-site risks of PPCPs by increasing soil nano-/micro-porosity.
本研究考察了一种表面-孔综合机制，该机制允许土壤有机质（SOM）影响三种代表性的药物和个人护理产品（PPCPs）-布洛芬、卡马西平和双酚 A-在农业土壤中的保留和迁移。使用施肥和未施肥土壤进行了一系列吸附-解吸批量试验和突破柱实验。结果表明，SOM 可以通过两种机制显著影响 PPCPs 的环境行为：表面覆盖和孔填充。分子 SOM 的表面覆盖降低了游离 PPCPs（如布洛芬）的吸附，但增加了非游离 PPCPs（如卡马西平和双酚 A）的吸附，而胶体 SOM 的孔填充通过提供限制扩散的纳米/微孔增强了所有 PPCPs 的保留。与原状土壤相比，PPCPs 在土壤微团聚体中的保留率更高，迁移率更低，这表明 SOM 含量和 SOM 改变的土壤孔结构对 PPCP 保留具有耦合效应。在有和没有 SOM 的情况下，用低表面张力溶液（即 20%乙醇）洗脱 PPCPs 的差异表明，PPCPs 更愿意留在充满 SOM 的孔中。总体而言，布洛芬具有很高的环境风险，而卡马西平和双酚 A 很容易在农业土壤（粉质粘壤土质地）中被延迟。本研究表明，SOM 的积累（特别是孔填充 SOM）通过增加土壤纳米/微孔度，有很大潜力降低 PPCPs 的场外风险。
