Zhang Ya-Nan, Yang Xing-Lun, Bian Yong-Rong, Gu Cheng-Gang, Wang Fang, Wang Dai-Zhang, Jiang Xin
Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Huan Jing Ke Xue. 2016 Aug 8;37(8):3201-3207. doi: 10.13277/j.hjkx.2016.08.048.
In this study, composite extraction of hydroxypropyl--cyclodextrin (HPCD) with rhamnolipid (RL) was selected to assess the bioavailability of polycyclic aromatic hydrocarbons (PAHs) to earthworms in red soil from Hainan, China, spiked with phenanthrene (Phe), pyrene (Pyr) and benzo (a) pyrene (BaP). The results showed that when RL was more than the critical micelle concentration, apparent solubility of PAHs increased due to micellar solubilization of RL. So more PAHs were desorbed from solid phase of soil. Real biological experiments showed that there was a good linear relationship between earthworm-accumulated PAHs and HPCD/RL-extracted PAHs (=0.98, =15). However, earthworm-accumulated PAHs was 2.04 times higher than HPCD-extracted PAHs, but only 1.15 times higher than HPCD/RL-extracted PAHs. This indicated that HPCD/RL was more actual and reliable than HPCD in the assessment of PAHs bioavailability to earthworms. Therefore, the addition of RL, to some extent, enhanced the prediction ability of HPCD in PAHs bioavailability, which might provide a new direction and implications in risk assessment and bioremediation of organic contaminants.
本研究选用羟丙基-β-环糊精（HPCD）与鼠李糖脂（RL）复合萃取法，以评估在中国海南红壤中添加菲（Phe）、芘（Pyr）和苯并（a）芘（BaP）后多环芳烃（PAHs）对蚯蚓的生物有效性。结果表明，当RL超过临界胶束浓度时，由于RL的胶束增溶作用，PAHs的表观溶解度增加。因此，更多的PAHs从土壤固相解吸出来。实际生物实验表明，蚯蚓体内积累的PAHs与HPCD/RL萃取的PAHs之间存在良好的线性关系（r = 0.98，n = 15）。然而，蚯蚓体内积累的PAHs比HPCD萃取的PAHs高2.04倍，但仅比HPCD/RL萃取的PAHs高1.15倍。这表明在评估PAHs对蚯蚓的生物有效性时，HPCD/RL比HPCD更实际、更可靠。因此，RL的添加在一定程度上提高了HPCD对PAHs生物有效性的预测能力，这可能为有机污染物的风险评估和生物修复提供新的方向和启示。
