Abstract：
Remediation of polycyclic aromatic hydrocarbon (PAH)-contaminated soil using thermal desorption technology typically requires very high temperatures, necessitating coupled microbial treatment for energy and cost reduction. This study investigated the fate and toxicity of PAHs as well as the responses of microbial communities following thermal treatment within a low temperature range. The optimal temperature for PAH mineralization was 20-28 °C, within the growth range of most mesophilic microorganisms. By contrast, 50 °C treatment almost completely inhibited PAH mineralization but resulted in the greatest detoxification effect particularly for cardiotoxicity and nephrotoxicity. A potential increase in toxicity was observed at 28 °C. Co-metabolism and non-extractable residue formation may play an interdependent role in thermally enhanced bioremediation. Moreover, alterations in bacterial communities were strongly associated with PAH mineralization and zebrafish toxicity, revealing that soil microorganisms play a direct role in PAH mineralization and served as ecological receptors reflecting changes in toxicity. Network analysis revealed that Firmicutes formed specific ecological communities at high temperature, whereas Acidobacteria and Proteobacteria act as primary PAH degraders at moderate temperature. These findings will enable better integration of strategies for thermal and microbial treatments in soil remediation.
摘要：
使用热解吸技术修复多环芳烃（PAH）污染的土壤通常需要非常高的温度，需要耦合的微生物处理以降低能量和成本。这项研究调查了PAHs的命运和毒性以及在低温范围内热处理后微生物群落的反应。PAH矿化的最佳温度为20-28°C，在大多数嗜温微生物的生长范围内。相比之下,50°C处理几乎完全抑制了PAH矿化，但产生了最大的解毒作用，特别是对于心脏毒性和肾毒性。在28°C观察到毒性的潜在增加。共代谢和不可提取的残留物形成可能在热增强的生物修复中起相互依赖的作用。此外，细菌群落的改变与PAH矿化和斑马鱼毒性密切相关，揭示土壤微生物在PAH矿化中起直接作用，并充当反映毒性变化的生态受体。网络分析表明，Firmicutes在高温下形成了特定的生态群落，而酸性细菌和变形杆菌在中等温度下充当主要的PAH降解剂。这些发现将使土壤修复中的热和微生物处理策略更好地整合。
