Department of Civil and Environmental Engineering, Stanford University, Stanford, California 94305-4020, USA.
Environ Sci Technol. 2013 Jan 15;47(2):1024-32. doi: 10.1021/es303770c. Epub 2012 Dec 28.
We present a first comprehensive set of experiments that demonstrate the performance of activated carbon (AC) to reduce the availability of polycyclic aromatic hydrocarbons (PAHs) including alkylated-PAHs in petroleum-impacted sediments. The uptake in polyethylene samplers for total PAHs in a well-mixed sediment slurry was reduced up to 99% and 98% for petroleum-impacted sediments with oil contents of 1% and 2%, respectively, by treatment with 5% AC. The AC showed similar efficiency for parent-PAHs and a suite of alkylated-PAHs, which predominate over parent-PAHs in petroleum-impacted sediments. A mass transfer model was used to simulate the AC performance in a slurry phase with site-specific mass transfer parameters determined in this study. Comparison between the experimental data and simulation results suggested that dissolved organic matter and/or oil phase may have attenuated the AC performance by a factor of 5-6 for 75-300 μm AC with 5% dose at one month. The attenuation in AC performance became negligible with increase in AC-sediment slurry contact time to 12 months and with decrease in AC particle size. The results show the potential for AC amendment to sequester PAHs in petroleum-impacted sediments and the effect of contact time and AC particle size on the efficiency of the treatment.
我们首次进行了一系列全面的实验，这些实验证明了活性炭（AC）可降低受石油影响的沉积物中多环芳烃（PAHs）的有效性，包括烷基化 PAHs。在含油率分别为 1%和 2%的石油污染沉积物的混合泥浆中，用 5%的 AC 处理后，聚乙烯采样器中总 PAHs 的吸收率分别高达 99%和 98%。AC 对母体 PAHs 和一系列烷基化 PAHs 的去除效率相似，而在受石油影响的沉积物中，烷基化 PAHs 比母体 PAHs 更为普遍。本文使用质量传递模型模拟了 AC 在泥浆相中吸附 PAHs 的性能，同时确定了本研究中特定于地点的质量传递参数。实验数据与模拟结果的比较表明，在一个月内，对于 75-300μm 的 AC，其剂量为 5%，溶解态有机物和/或油相可能会使 AC 的性能降低 5-6 倍。随着 AC-沉积物泥浆接触时间增加到 12 个月和 AC 粒径减小，AC 性能的衰减变得可以忽略不计。研究结果表明，AC 添加剂有可能将 PAHs 隔离在受石油影响的沉积物中，并且接触时间和 AC 粒径对处理效率有影响。
