School of Environmental Science and Engineering, Shaanxi University of Science & Technology, Xi'an, 710021, People's Republic of China.
College of Environmental and Chemical Engineering, Xi'an Polytechnic University, Xi'an, 710048, Shaanxi, China.
Environ Geochem Health. 2023 Aug;45(8):6009-6026. doi: 10.1007/s10653-023-01605-9. Epub 2023 May 19.
Heavy metal pollution of soil has become a public concern worldwide since it threats food safety and human health. Sustainable and environmental-friendly remediation technology is urgently needed. Therefore, we investigated the properties and heavy metal removal ability of Enterobacter asburiae G3 (G3), Enterobacter tabaci I12 (I12), and explored the feasibility of remediation Cd, Pb co-contaminated soil by the combination of G3/I12 and biochar. Our results indicated that both strains are highly resistant to Cd, Pb and maintain plant growth-promoting properties. The removal efficiency of G3 for Cd and Pb were 76.79-99.43%, respectively, while the removal efficiency of I12 for Cd and Pb were 62.57-99.55%, respectively. SEM-EDS and XRD analysis revealed that the morphological and structural changes occurred upon heavy metal exposure, metal precipitates were also detected on cell surface. FTIR analysis indicated that functional groups (-OH, -N-H, -C = O, -C-N, -PO) were involved in Cd/Pb immobilization. Application of the bacteria, biochar, or their combination decreased the acid-extractable Cd, Pb in soil while increased the residual fractions, meanwhile, the bioavailability of both metal elements declined. Besides, these treatments increased soil enzyme (sucrase, catalase and urease) activity and accelerated pakchoi growth, heavy metal accumulation in pakchoi was depressed upon bacteria and/or biochar application, and a synergistic effect was detected when applying bacteria and biochar together. In BC + G3 and BC + I12 treated plants, the Cd and Pb accumulation decreased by 24.42% and 52.19%, 17.55% and 47.36%, respectively. Overall, our study provides an eco-friendly and promising in situ technology that could be applied in heavy metal remediation.
土壤重金属污染已成为全世界关注的公共问题，因为它威胁到食品安全和人类健康。因此，迫切需要可持续和环境友好的修复技术。因此，我们研究了肠杆菌属（Enterobacter）G3（G3）和肠杆菌属（Enterobacter）I12（I12）的特性及其去除重金属的能力，并探索了 G3/I12 与生物炭结合修复 Cd、Pb 复合污染土壤的可行性。我们的研究结果表明，这两种菌株对 Cd、Pb 均具有高度抗性，并保持了植物促生特性。G3 对 Cd 和 Pb 的去除效率分别为 76.79-99.43%，而 I12 对 Cd 和 Pb 的去除效率分别为 62.57-99.55%。SEM-EDS 和 XRD 分析表明，重金属暴露导致细胞形态和结构发生变化，细胞表面也检测到金属沉淀。FTIR 分析表明，功能基团（-OH、-N-H、-C = O、-C-N、-PO）参与了 Cd/Pb 的固定。细菌、生物炭或其组合的应用降低了土壤中可酸提取的 Cd、Pb，增加了残渣分数，同时降低了两种金属元素的生物有效性。此外，这些处理还提高了土壤酶（蔗糖酶、过氧化氢酶和脲酶）活性，加速了小白菜的生长，细菌和/或生物炭的应用抑制了重金属在小白菜中的积累，并检测到细菌和生物炭同时应用时存在协同效应。在 BC + G3 和 BC + I12 处理的植物中，Cd 和 Pb 的积累分别减少了 24.42%和 52.19%、17.55%和 47.36%。总之，本研究提供了一种环保且有前景的原位修复技术，可应用于重金属修复。
