Modeling the Mass Transfer of Hydrophobic Organic Pollutants in Briefly and Continuously Mixed Sediment after Amendment with Activated Carbon
Modeling the Mass Transfer of Hydrophobic Organic Pollutants in Briefly and Continuously Mixed Sediment after Amendment with Activated Carbon
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DOI：
10.1021/es903582n
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发表时间：
2010-05-01
影响因子：
11.4
通讯作者：
Werner, David
中科院分区：
文献类型：
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作者：
Hale, Sarah E.;Werner, David
活性碳(AC)修饰剂是一种被持久性有机污染物污染的沉积物的原位修复技术，目前正在进行研究。了解污染物从沉积物颗粒上较弱结合部位到AC颗粒内较强结合部位的质量转移，对于评估这一策略非常重要。本文研究了在两种混合方式下，在AC存在和不存在的情况下，多环芳烃(PAHs)从泰恩河沉积物到聚乙烯(PE)被动采样器的传质。比较了连续混合和将AC加入系统的短暂初始混合期，以及随后沉淀物中的未混合条件。在两种情况下，交流接触12个月后，PE采样器中总PAH浓度的降幅均大于99%。基于用于模拟混合良好的AC-沉积物泥浆的概念，进一步发展了描述简单混合体系的数值模型。这些模型可以预测不同的AC-泥沙混合制度的预期修复效果的上限和下限。泰恩河底泥是一个结合力强、释放缓慢的污染源，混合方式对其处理效果影响不大。然而，预计对含有更多可用污染物的受污染沉积物的影响会更大。
Activated carbon (AC) amendment is currently being investigated as an in situ remediation technique for sediments contaminated by persistent organic pollutants. Understanding the mass transfer of pollutants from weaker binding sites on sediment particles, to stronger binding sites inside AC particles, is important for the evaluation of this strategy. Here we study the mass transfer of polycyclic aromatic hydrocarbons (PAHs) from River Tyne sediment to polyethylene (PE) passive samplers in the presence and absence of AC under two mixing regimes. Continuously mixing and a brief initial mixing period to incorporate AC to the system, followed by unmixed conditions in settled sediments, were compared. The reduction in total PAH concentration in the PE sampler was greater than 99% after 12 months AC contact for both conditions. A numerical model based on concepts used to simulate well-mixed AC-sediment slurries was further developed to describe the briefly mixed system. These models could predict upper and lower limits for the expected remediation effectiveness for variable AC-sediment mixing regimes. It appears that mixing mode has a small impact on the treatment effectiveness for River Tyne sediment which has a strongly bound, slowly released pollutant source. However, a greater impact is anticipated for contaminated sediments containing more available pollutants.