Sun Ming-Ming, Teng Ying, Luo Yong-Ming, Li Zhen-Gao, Jia Zhong-Jun, Zhang Man-Yun
Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
Huan Jing Ke Xue. 2013 Jun;34(6):2428-35.
Polycyclic aromatic hydrocarbon (PAH) polluted sites caused by abandoned coking plants have attracted great attentions. This study investigated the feasibility of using methyl-beta-cyclodextrin (MCD) solution to enhance ex situ soil washing for extracting PAHs. Treatment with elevated temperature (50 degrees C) in combination with ultrasonication (35 kHz, 30 min) at 100 g x L(-1) was effective. It was found that 96.7% +/- 2.4% of 3-ring PAH, 89.7% +/- 3.2% of 4-ring PAH, 76.3% +/- 2.2% of 5 (+6)-ring PAH and 91.3% +/- 3.1% of total PAHs were removed from soil after five successive washing cycles. The desorption kinetics of PAHs from contaminated soil was determined before and after successive washings. The 400 h Tenax extraction of PAHs from soil was decreasing gradually with increasing washing times. Furthermore, the F(r), F(sl), k(r), k(sl) and k(vl) were significantly lower than those of CK (P < 0.01). Therefore, considering the removal efficiency and potential environmental risk after soil )ashing, successive washing three times was selected as a reasonable parameter. These results have practical implications for site risk assessment and cleanup strategies.
废弃焦化厂造成的多环芳烃（PAH）污染场地已引起广泛关注。本研究调查了使用甲基-β-环糊精（MCD）溶液强化异位土壤淋洗提取多环芳烃的可行性。在100 g×L⁻¹的条件下，采用50℃高温结合超声处理（35 kHz，30分钟）是有效的。结果发现，经过连续五个淋洗周期后，土壤中96.7%±2.4%的三环多环芳烃、89.7%±3.2%的四环多环芳烃、76.3%±2.2%的五环（+六环）多环芳烃以及91.3%±3.1%的总多环芳烃被去除。在连续淋洗前后测定了多环芳烃从污染土壤中的解吸动力学。随着淋洗次数增加，从土壤中提取多环芳烃的400小时Tenax提取量逐渐降低。此外，F(r)、F(sl)、k(r)、k(sl)和k(vl)均显著低于对照（P < 0.01）。因此，综合考虑土壤淋洗后的去除效率和潜在环境风险，选择连续淋洗三次作为合理参数。这些结果对场地风险评估和清理策略具有实际意义。
