Electro-bioremediation of contaminated sediment by electrode enhanced capping.
Electro-bioremediation of contaminated sediment by electrode enhanced capping.
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DOI：
10.1016/j.jenvman.2015.03.023
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发表时间：
2015-05-15
影响因子：
8.7
通讯作者：
Reible D
中科院分区：
文献类型：
--
作者：
Yan F;Reible D
由于沉积物中的还原条件，原位封盖通常消除或减缓烃类的自然降解。本研究的目的是展示一种反应性盖帽技术，电极增强帽，产生有利的条件，烃类降解和评估这种反应性盖帽技术污染沉积物修复。将两个石墨电极水平放置在盖中的不同层处，并连接到2 V的外部电源。阳极周围的氧化还原电位增加，pH降低。在阳极附近，菲浓度降低，多环芳烃降解基因增加。在阳极下方0-1 cm沉积物中的菲浓度在约70天内下降到初始浓度的约50%，而对照反应器中的菲水平保持不变。建立了一个模拟反应-扩散过程的电极强化帽盖退化模型，模型结果表明，在阳极附近产生了一个反应主导区。虽然降解为主的区域很薄，但沉积物盖环境中的运输过程通常足够缓慢，使这一层能够作为碳氢化合物去污的可渗透反应屏障。
In-situ capping often eliminates or slows natural degradation of hydrocarbon due to the reducing conditions in the sediments. The purpose of this research was to demonstrate a reactive capping technique, an electrode enhanced cap, to produce favorable conditions for hydrocarbon degradation and evaluate this reactive capping technique for contaminated sediment remediation. Two graphite electrodes were placed horizontally at different layers in a cap and connected to external power of 2 V. Redox potentials increased and pH decreased around the anode. Phenanthrene concentration decreased and PAH degradation genes increased in the vicinity of the anode. Phenanthrene concentrations at 0–1 cm sediment beneath the anode decreased to ~50% of initial concentration over ~70 days, while phenanthrene levels in control reactor kept unchanged. A degradation model of electrode enhanced capping was developed to simulate reaction-diffusion processes, and model results show that a reaction-dominated region was created in the vicinity of the anode. Although the degradation dominated region was thin, transport processes in a sediment cap environment are typically sufficiently slow to allow this layer to serve as a permeable reactive barrier for hydrocarbon decontamination.