Bioremediation of Cd-spiked soil using earthworms (Eisenia fetida): Enhancement with biochar and Bacillus megatherium application
Bioremediation of Cd-spiked soil using earthworms (Eisenia fetida): Enhancement with biochar and Bacillus megatherium application
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使用蚯蚓（Eisenia fetida）对加镉土壤进行生物修复：使用生物炭和巨大芽孢杆菌进行强化
DOI：
10.1016/j.chemosphere.2020.128517
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发表时间：
2020
期刊：
影响因子：
8.8
通讯作者：
Zhang Zengqiang
中科院分区：
文献类型：
--
作者：
Ran Xiao;Liu Xiangyu;Ali Amjad;Chen Anle;Zhang Muyuan;Li Ronghua;Chang Hong;Zhang Zengqiang
在这项研究中，我们评估了生物炭和巨大芽孢杆菌的影响，从人工污染的土壤中去除镉蚯蚓（蚯蚓）。在35天的修复期内，超过30%的镉被蚯蚓从污染土壤中去除（镉含量为2.5 mg kg−1），两种添加剂都促进了镉的去除。此外，超过22%的减少提取镉含量也实现了蚯蚓。Cd在蚯蚓体内的累积量随修复时间的延长而增加，且Cd累积量依次为生物炭+生物炭（T3）>生物炭+巨大芽孢杆菌（T4）>生物炭单独（T2）。蚯蚓对Cd的生物富集系数（BCF）均大于1，表明蚯蚓对Cd有富集作用，其中T4和T3的BCF均较高（分别为94.4%和84.5%）。T3和T4下蚯蚓对金属结合的生物炭颗粒的摄食和Cd迁移率的提高分别是蚯蚓对Cd修复能力增强的主要原因。通过修复，微生物群落在两个，土壤和蚯蚓肠道，表现出高度的相似性，而较低的水平的细菌丰度观察蚯蚓肠道相比，在土壤中。最终，土壤变得更加肥沃，并表现出更高的酶活性修复后。因此，我们得出的结论是，单独或与生物炭或巨大芽孢杆菌组合的生物活性炭，可以是一种替代的方法修复镉污染的土壤。
In this study, we evaluated the influence of biochar and Bacillus megatherium on Cd removal from artificially contaminated soils using earthworms (Eisenia fetida). Within a 35-days remediation period, over 30% of Cd was removed by earthworms from the contaminated soil (with Cd at ∼ 2.5 mg kg−1), and both additives facilitated Cd removal. Additionally, over 22% reduction in the extractable Cd contents was also achieved by earthworms. Cd accumulated in earthworms steadily increased through remediation, and the accumulated Cd decreased in the order of earthworm + biochar (T3) > earthworm + Bacillus megatherium (T4) > earthworm alone (T2). The bioaccumulation factors (BCF) were above 1, indicating the enrichment of Cd in earthworms, and there were higher BCF for both T4 (944%) and T3 (845%). The ingestion of metal-bonded biochar particle and the elevated Cd mobility would be the main reason for the enhanced Cd-remediation by earthworms under T3 and T4, respectively. Through remediation, microbiota communities in both, soil and earthworm guts, demonstrated high similarity, while a lower level of bacterial abundance was observed in earthworm guts compared with that in soils. Eventually, soils became more fertile and demonstrated higher enzyme activities after remediation. Therefore, we concluded that earthworm, alone or combined with biochar or Bacillus megatherium could be an alternative method for Cd-contaminated soil remediation.