Two‐Liquid‐Phase Slurry Bioreactors To Enhance the Degradation of High‐Molecular‐Weight Polycyclic Aromatic Hydrocarbons in Soil
Two‐Liquid‐Phase Slurry Bioreactors To Enhance the Degradation of High‐Molecular‐Weight Polycyclic Aromatic Hydrocarbons in Soil
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DOI：
10.1021/bp000118j
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发表时间：
2000
影响因子：
2.9
通讯作者：
R. Villemur;Eric Déziel;A. Benachenhou;J. Marcoux;E. Gauthier;F. Lépine;R. Beaudet;Y. Comeau
中科院分区：
文献类型：
--
作者：
R. Villemur;Eric Déziel;A. Benachenhou;J. Marcoux;E. Gauthier;F. Lépine;R. Beaudet;Y. Comeau
高相对分子质量(HMW)多环芳烃(PAHs)是由于其在水中的低溶解度以及其在土壤和沉积物中的固持而持续存在于环境中的污染物。研究了在土壤泥浆中添加水不相容、不可生物降解和生物相容的液体--硅油，以促进土壤中多环芳烃的解吸并提高其生物利用率。首先，在灭菌土壤(总挥发性固体含量为0.65%的沙土)中加入菲、芘、黄原烯和苯并[a]芘，在三种两液相(TLP)泥浆体系中连续4天测定了菲、芘、黄原烯和苯并[a]芘在硅油中的迁移，每种体系都含有30%(w/v)土壤，但硅油的体积分别为2.5%、7.5%和15%[v/v]。在含15%硅油的TLP泥浆体系中，除白藜芦醇外，大部分多环芳烃从土壤中转移到硅油中。在最初的8h内，多环芳烃发生了快速的转移，可能是由于未溶解的和吸附较差的多环芳烃被提取出来的结果。在此之后的一段时间内，发生了缓慢但持续的转移，这表明提取出了更紧密结合的多环芳烃。其次，利用从杂酚油污染的土壤中分离的微生物种群，在TLP泥浆系统中对HMW多环芳烃降解联合体进行浓缩。然后将该联合体加入到另外三个TLP泥浆系统中，每个泥浆系统包含30%(w/v)的灭菌土壤，这些土壤已经被芘、大黄烯和苯并[a]芘人工污染，但不同数量的硅油(10%、20%和30%[v/v])。得到的TLP泥浆生物反应器比含有相同污染土壤但没有油相的对照泥浆生物反应器的效率要高得多。在含30%硅油的TLP泥浆生物反应器中，芘的降解速率为19 mg L−1d−1，4d后未检测到芘。在30%TLP浆态生物反应器中，白藜芦醇和苯并[a]芘的降解率分别为3.5mg1 d−和0.94mgTLP1d−1。这是首次将TLP系统与泥浆系统相结合来提高土壤中多环芳烃的生物降解性。
High‐molecular‐weight (HMW) polycyclic aromatic hydrocarbons (PAHs) are pollutants that persist in the environment due to their low solubility in water and their sequestration by soil and sediments. The addition of a water‐immiscible, nonbiodegradable, and biocompatible liquid, silicone oil, to a soil slurry was studied to promote the desorption of PAHs from soil and to increase their bioavailability. First, the transfer into silicone oil of phenanthrene, pyrene, chrysene, and benzo[a]pyrene added to a sterilized soil (sandy soil with 0.65% total volatile solids) was measured for 4 days in three two‐liquid‐phase (TLP) slurry systems each containing 30% (w/v) soil but different volumes of silicone oil (2.5%, 7.5%, and 15% [v/v]). Except for chrysene, a high percentage of these PAHs was transferred from soil to silicone oil in the TLP slurry system containing 15% silicone oil. Rapid PAH transfer occurred during the first 8 h, probably resulting from the extraction of nonsolubilized and of poorly sorbed PAHs. This was followed by a period in which a slower but constant transfer occurred, suggesting extraction of more tightly bound PAHs. Second, a HMW PAH‐degrading consortium was enriched in a TLP slurry system with a microbial population isolated from a creosote‐contaminated soil. This consortium was then added to three other TLP slurry systems each containing 30% (w/v) sterilized soil that had been artificially contaminated with pyrene, chrysene, and benzo[a]pyrene, but different volumes of silicone oil (10%, 20%, and 30% [v/v]). The resulting TLP slurry bioreactors were much more efficient than the control slurry bioreactor containing the same contaminated soil but no oil phase. In the TLP slurry bioreactor containing 30% silicone oil, the rate of pyrene degradation was 19 mg L−1 day−1 and no pyrene was detected after 4 days. The degradation rates of chrysene and benzo[a]pyrene in the 30% TLP slurry bioreactor were, respectively, 3.5 and 0.94 mg L−1 day−1. Low degradation of pyrene and no significant degradation of chrysene and benzo[a]pyrene occurred in the slurry bioreactor. This is the first report in which a TLP system was combined with a slurry system to improve the biodegradation of PAHs in soil.