Dept Environm Sci, Zhejiang Univ, Hangzhou 310058, Zhejiang, China; Zhejiang Prov Key Lab Organ Pollut Proc Control, Hangzhou 310058, Zhejiang, China.
Dept Environm Sci & Engn, Xiangtan Univ, Xiangtan 411105, China.
Sci Total Environ. 2019 Feb 25;653:658-666. doi: 10.1016/j.scitotenv.2018.10.385. Epub 2018 Oct 31.
The present study was conducted to explore the mechanisms of surfactant-enhanced phytoremediation of soils contaminated with polycyclic aromatic hydrocarbons (PAHs), focusing on the bioavailability of PAHs and microbial diversity. We investigated the remediation efficiencies of phenanthrene and pyrene after the addition of mixed surfactants (sodium dodecyl benzene sulfonate (SDBS) and Tween 80) of different ratios (1:1, 1:2, and 2:1) at the concentration of 100 mg/kg to soils cultured with ryegrass (Lolium multiflorum L.). The fractions of phenanthrene and pyrene were determined using a sequential extraction method, and the microbial diversity was evaluated using 16S rRNA gene high-throughput sequencing. The results showed that mixed surfactants could enhance the remediation efficiencies of PAHs, and mainly occurred in the initial 21 days. Mixed surfactants at the ratio of 1:1 (HM1) showed the best remediation efficiency in enhancing the dissipation of pyrene in 21 days. Mixed surfactants showed little effects on the removal of phenanthrene. In general, HM1 significantly decreased the bioavailable, bound and residual fractions of pyrene; additionally, higher abundances of PAH-degradation bacteria and degradation-related genes were observed. Pearson correlation analysis among PAH degraders, degradation-related genes and bioavailable fraction of PAHs was performed. Our results indicated that mixed surfactants could promote the transformation of pyrene from the bound and residual fractions to bioavailable fractions and enhance the abundances of PAH degradation bacteria and PAH degradation-related genes, thereby enhancing the degradation of pyrene.
本研究旨在探讨表面活性剂增强修复多环芳烃（PAHs）污染土壤的机制，重点研究 PAHs 的生物可利用性和微生物多样性。我们研究了在浓度为 100mg/kg 的条件下，添加不同比例（1:1、1:2 和 2:1）混合表面活性剂（十二烷基苯磺酸钠（SDBS）和吐温 80）后，土壤中添加混合表面活性剂（1:1、1:2 和 2:1）对黑麦草（Lolium multiflorum L.）培养土壤中菲和芘的修复效率。采用连续提取法测定菲和芘的赋存形态，采用 16S rRNA 基因高通量测序评价微生物多样性。结果表明，混合表面活性剂可以提高 PAHs 的修复效率，主要发生在最初的 21 天内。在 21 天内，混合表面活性剂比例为 1:1（HM1）在增强芘的降解方面表现出最佳的修复效率。混合表面活性剂对菲的去除影响较小。总的来说，HM1 显著降低了芘的生物可利用、结合和残留分数；此外，观察到更多的 PAH 降解菌和降解相关基因的丰度增加。对 PAH 降解菌、降解相关基因和 PAHs 生物可利用分数之间进行了 Pearson 相关性分析。我们的结果表明，混合表面活性剂可以促进芘从结合和残留分数向生物可利用分数的转化，增强 PAH 降解菌和 PAH 降解相关基因的丰度，从而增强芘的降解。
