Savron , 130 Stone Road West, Guelph, ON, Canada N1G 3Z2.
Department of Civil and Environmental Engineering, The University of Western Ontario , London, ON, Canada N6A 5B9.
Environ Sci Technol. 2015 Dec 15;49(24):14334-42. doi: 10.1021/acs.est.5b03177. Epub 2015 Nov 16.
Self-sustaining treatment for active remediation (STAR) is an emerging, smoldering-based technology for nonaqueous-phase liquid (NAPL) remediation. This work presents the first in situ field evaluation of STAR. Pilot field tests were performed at 3.0 m (shallow test) and 7.9 m (deep test) below ground surface within distinct lithological units contaminated with coal tar at a former industrial facility. Self-sustained smoldering (i.e., after the in-well ignition heater was terminated) was demonstrated below the water table for the first time. The outward propagation of a NAPL smoldering front was mapped, and the NAPL destruction rate was quantified in real time. A total of 3700 kg of coal tar over 12 days in the shallow test and 860 kg over 11 days in the deep test was destroyed; less than 2% of total mass removed was volatilized. Self-sustaining propagation was relatively uniform radially outward in the deep test, achieving a radius of influence of 3.7 m; strong permeability contrasts and installed barriers influenced the front propagation geometry in the shallow test. Reductions in soil hydrocarbon concentrations of 99.3% and 97.3% were achieved in the shallow and deep tests, respectively. Overall, this provides the first field evaluation of STAR and demonstrates that it is effective in situ and under a variety of conditions and provides the information necessary for designing the full-scale site treatment.
自维持燃烧处理（STAR）是一种新兴的基于闷烧的非水相液体（NAPL）修复技术。本工作首次对 STAR 进行了现场评估。在一个前工业设施的不同岩性单元中，在地下水以下 3.0 m（浅层试验）和 7.9 m（深层试验）处进行了试点现场试验，该单元受到煤焦油的污染。首次在地下水位以下证明了自维持闷烧（即井内点火加热器关闭后）。绘制了 NAPL 闷烧前沿的向外扩展图，并实时量化了 NAPL 破坏率。浅层试验共处理了 12 天的 3700 千克煤焦油，深层试验处理了 11 天的 860 千克煤焦油；总去除量中只有不到 2%挥发。深层试验中，自维持传播在径向向外相对均匀，影响半径达到 3.7 m；强渗透率对比和安装的障碍物影响了浅层试验中前沿的传播几何形状。浅层和深层试验中，土壤烃浓度分别降低了 99.3%和 97.3%。总的来说，这是对 STAR 的首次现场评估，证明了它在各种条件下的原位处理是有效的，并提供了设计现场全规模处理所需的信息。
