Lee G T, Ro H M, Lee S M
National Instrumentation Center for Environmental Management, Seoul National University, San 56-1 Sillim-dong, Gwanak-gu, Seoul 151-921, Korea.
Environ Technol. 2007 Aug;28(8):853-60. doi: 10.1080/09593332808618847.
Bench-scale experiments for electrokinetically enhanced bioremediation of diesel in low permeability soils were conducted. An electrokinetic reactor (ER) was filled with kaolin that was artificially contaminated with diesel at a level of 2500 mg kg(-1). A constant voltage gradient of 1.0 V cm(-1) was applied. In phosphorus transport experiments, KH2PO4 was not distributed homogeneously along the ER, and most of the transported phosphorus was converted to water-insoluble aluminum phosphate after 12 days of electrokinetic (EK) operation. However, the advancing P front of triethyl phosphate (TEP) progressed with time and resulted in uniform P distribution. The treatments employed in the electrokinetically enhanced bioremediation of diesel were control (no addition of nitrogen and phosphorus), NP (KNO3+ KH2PO4), NT (KNO3+ TEP), UP (urea+ KH2PO4), and UT (urea+TEP). Analysis of effluent collected during the first 12 days of EK operation showed that diesel was not removed from the kaolin. After nutrient delivery, using the EK operation, the ER was transferred into an incubator for the biodegradation process. After 60 days of biodegradation, the concentrations of diesel in the kaolin for the NP, NT, UP, UT, and control treatments were 1356, 1002, 1658, 1612, and 2003 mg kg(-1), respectively. The ratio of biodegraded diesel concentration to initial concentration (2465 mg kg(-1)) in NP, NT, UP, UT, and control were 45.0%, 59.4%, 32.7%, 34.6%, and 18.7%, respectively. This result showed that TEP, treated along with NO3-, was most effective for the biodegradation of diesel. TEP was delivered more efficiently to the target zones and with less phosphorus loss than KH2PO4. However, this facilitated phosphorus delivery was effective in biodegrading diesel under anaerobic conditions only when electron acceptors, such as NO3-, were present.
开展了低渗透性土壤中柴油电动强化生物修复的实验室规模实验。一个电动反应器（ER）填充了人工污染柴油至2500 mg kg(-1)水平的高岭土。施加了1.0 V cm(-1)的恒定电压梯度。在磷迁移实验中，KH2PO4未沿ER均匀分布，并且在电动（EK）运行12天后，大部分迁移的磷转化为水不溶性磷酸铝。然而，磷酸三乙酯（TEP）的推进磷前沿随时间推进并导致磷均匀分布。柴油电动强化生物修复中采用的处理方法有对照（不添加氮和磷）、NP（KNO3 + KH2PO4）、NT（KNO3 + TEP）、UP（尿素 + KH2PO4）和UT（尿素 + TEP）。对EK运行前12天收集的流出物分析表明，柴油未从高岭土中去除。在通过EK运行进行养分输送后，将ER转移到培养箱中进行生物降解过程。生物降解60天后，NP、NT、UP、UT和对照处理的高岭土中柴油浓度分别为1356、1002、1658、1612和2003 mg kg(-1)。NP、NT、UP、UT和对照中生物降解柴油浓度与初始浓度（2465 mg kg(-1)）的比值分别为45.0%、59.4%、32.7%、34.6%和18.7%。该结果表明，与NO3-一起处理的TEP对柴油生物降解最有效。与KH2PO4相比，TEP更有效地输送到目标区域且磷损失更少。然而，只有当存在诸如NO3-等电子受体时，这种促进的磷输送在厌氧条件下对柴油生物降解才有效。
