Rehmann Lars, Prpich George P, Daugulis Andrew J
Department of Chemical Engineering, Queen's University, Kingston, Ontario, Canada K7L 3N6.
Chemosphere. 2008 Oct;73(5):798-804. doi: 10.1016/j.chemosphere.2008.06.006.
The feasibility of a two-step treatment process has been assessed at laboratory scale for the remediation of soil contaminated with a model mixture of polycyclic aromatic hydrocarbons (PAHs) (phenanthrene, pyrene, and fluoranthene). The initial step of the process involved contacting contaminated soil with thermoplastic, polymeric pellets (polyurethane). The ability of three different mobilizing agents (water, surfactant (Biosolve) and isopropyl alcohol) to enhance recovery of PAHs from soil was investigated and the results were compared to the recovery of PAHs from dry soil. The presence of isopropyl alcohol had the greatest impact on PAH recovery with approximately 80% of the original mass of PAHs in the soil being absorbed by the polymer pellets in 48 h. The second stage of the suggested treatment involved regeneration of the PAH loaded polymers via PAH biodegradation, which was carried out in a solid-liquid two-phase partitioning bioreactor. In addition to the PAH containing polymer pellets, the bioreactor contained a microbial consortium that was pre-selected for its ability to degrade the model PAHs and after a 14 d period approximately 78%, 62% and 36% of phenanthrene, pyrene, and fluoranthene, respectively, had been desorbed from the polymer and degraded. The rate of phenanthrene degradation was shown to be limited by mass transfer of phenanthrene from the polymer pellets. In case of pyrene and fluoranthene a combination of mass transfer and biodegradation rate might have been limiting.
在实验室规模下，已评估了两步处理工艺用于修复受多环芳烃（PAHs）（菲、芘和荧蒽）模型混合物污染土壤的可行性。该工艺的初始步骤是使受污染土壤与热塑性聚合物颗粒（聚氨酯）接触。研究了三种不同的活化剂（水、表面活性剂（Biosolve）和异丙醇）提高PAHs从土壤中回收率的能力，并将结果与PAHs从干燥土壤中的回收率进行了比较。异丙醇的存在对PAHs的回收率影响最大，48小时内土壤中约80%的原始PAHs质量被聚合物颗粒吸收。建议处理的第二阶段涉及通过PAHs生物降解对负载PAHs的聚合物进行再生，这在固液两相分配生物反应器中进行。除了含PAHs的聚合物颗粒外，生物反应器还含有一个微生物群落，该群落因其降解模型PAHs的能力而预先筛选，经过14天，菲、芘和荧蒽分别约有78%、62%和36%从聚合物中解吸并降解。结果表明，菲的降解速率受菲从聚合物颗粒传质的限制。对于芘和荧蒽，传质和生物降解速率的组合可能起到了限制作用。
