纳米零价铁(nZVI)对蚯蚓-微生物-土壤生态系统的毒性效应研究

刘嫦娥; 岳敏慧; 谭辉林; 张悦; 张维兰; 肖艳兰; 潘瑛; 段昌群

doi:10.13930/j.cnki.cjea.210156

纳米零价铁(nZVI)对蚯蚓-微生物-土壤生态系统的毒性效应研究

doi: 10.13930/j.cnki.cjea.210156

云南大学生态与环境学院/云南省高原山地生态与退化环境修复重点实验室/云南省高原湖泊生态修复及流域管理国际联合研究中心　昆明　650091

基金项目: 国家自然科学基金项目(U2002208)、云南省科技计划重点研发项目(2019BC001, 2018DG005)和云南大学大学生创新创业项目(202004169)资助

详细信息

作者简介:
刘嫦娥, 主要从事污染与恢复生态学研究。E-mail: change@ynu.edu.cn

通讯作者:
段昌群，主要研究方向为污染与恢复生态学。E-mail: chqduan@ynu.edu.cn

中图分类号: X503
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出版历程
- 收稿日期: 2021-03-15
- 录用日期: 2021-05-08
- 网络出版日期: 2021-06-22
- 刊出日期: 2021-10-01

Effects of nano-zero-valent iron (nZVI) on earthworm-bacteria-soil systems

School of Ecology and Environmental Sciences, Yunnan University / Yunnan Key Laboratory for Plateau Mountain Ecology and Restoration of Degraded Environments / International Cooperative Center of Plateau Lake Ecological Restoration and Watershed Management of Yunnan, Kunming 650091, China

Funds: The study was supported by the National Natural Science Foundation of China (U2002208), the Key Research and Development Project of Yunnan Province (2019BC001, 2018DG005) and the Students Innovations Project of Yunnan University (202004169)

More Information

Corresponding author: E-mail: chqduan@ynu.edu.cn

摘要

摘要: 为解决土壤重金属污染问题，纳米零价铁(nZVI)被广泛应用且备受关注, 而nZVI对土壤无脊椎动物、土壤质量、微生物群落等的潜在影响缺乏系统的研究。本文以赤子爱胜蚓(Eisenia foetida) [蚯蚓密度为0、10条∙kg⁻¹(土)]为研究对象, 探讨不同浓度nZVI (nZVI土壤质量为0、0.05%、0.25%和0.50%) 暴露15 d、30 d和45 d后，蚯蚓-微生物-土壤生态系统的响应, 为评价nZVI的环境安全性提供参考。结果表明, 暴露45 d后, nZVI对蚯蚓存活率和生物量无显著影响, 0.50% nZVI处理的蚯蚓存活率和体内MDA含量与15 d相比分别降低27.66%和0.86 nmol∙g⁻¹; 而蚯蚓生物量和CAT活性分别增加1.20倍和2.62倍。门或属水平下, nZVI对土壤微生物相对丰度、多样性指数和丰度指数无显著影响; 与无添加nZVI处理相比，蚯蚓介导下 0.50% nZVI处理土壤中大团聚体(>250 μm)所占比例、团聚体平均重量直径和速效磷含量分别显著升高15.69%、12.59%和21.20%。蚯蚓介导下nZVI处理中土壤大团聚体所占比例、团聚体平均重量直径显著高于无蚯蚓投加的nZVI处理, 可见, nZVI胁迫下蚯蚓活动极显著提高土壤团聚体结构的稳定性(P<0.01)。本研究发现长期暴露nZVI对土壤微生物群落特征无显著影响, 但可以促进蚯蚓的生长, 从而进一步提高了土壤营养元素的生物有效性, 为nZVI应用于污染修复与治理的环境安全性评估提供了科学依据。
- 纳米零价铁 /
- 赤子爱胜蚓 /
- 毒性效应 /
- 土壤团聚体 /
- 细菌多样性
Abstract: Nano-zero-valent iron (nZVI) is widely used to remedy soil heavy metal pollution. However, the potential effects of nZVI on soil invertebrates, soil quality and microbial communities have not been well studied. In this study, we used Eisenia foetida (0, 10 pieces per kilogram soil) as the test species and examined the potential effects of nZVI (mass ratios of 0, 0.05%, 0.25%, and 0.50%) on the earthworm-bacteria-soil ecosystems after 15, 30, and 45 days of exposure. The results showed that after 45 days of exposure, there was no significant difference in survival rate and biomass of earthworms. The earthworm survival rate and content of malondialdehyde in the 0.50% nZVI system decreased by 27.66% and 0.86 nmol∙g⁻¹, respectively, compared with those on day 15. However, the earthworm biomass increased by 1.20 times, and the catalase activity increased by 2.62 times. At the phylum or genus level, nZVI had no significant effects on the relative abundance, diversity index, and abundance index of soil microorganisms. Compared with the 0 nZVI system, the proportion of soil large aggregates (>250 μm), the average weight diameter of soil aggregates, and the content of available phosphorus (P) in the 0.50% nZVI system increased by 15.69%, 12.59%, and 21.20% under earthworm-mediated conditions, respectively. The proportion of soil macroaggregates and the average weight diameter of soil aggregates in the earthworm and nZVI composite systems were significantly higher than those in the corresponding single nZVI system, and earthworm activity significantly improved the stability of soil aggregates under nZVI stress (P<0.01). In this study, we found that long-term exposure to nZVI had no significant toxic effects on the community characteristics of soil microorganisms but promoted the growth of earthworms, which further improved the bioavailability of soil nutrients. This study provides a scientific basis for environmental safety assessments of nZVI in soil restoration applications.
- Nano-zero-valent iron /
- Eisenia fetida /
- Toxic effects /
- Soil aggregates /
- Bacterial diversity

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图 1 不同添加量纳米零价铁(nZVI)对蚯蚓存活率(a)和生物量减少量(b)的影响

不同大写字母表示同一处理不同时间在P<0.05水平差异显著, 不同小写字母表示同一时间不同处理在P <0.05水平差异显著。Different captial letters mean significant differences of a given nZVI treatment measured at different times at P<0.05 level. Different lowercase letters mean significant differences among nZVI treatments at same given obervation time at P<0.05 level.

Figure 1. Effect of nano-zero-valent iron (nZVI) on survival rate (a) and biomass reduction (b) of earthworm

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图 2 纳米零价铁(nZVI)对蚯蚓SOD活性(a)、CAT活性(b)、丙二醛(MDA)含量(c)和脯氨酸含量(d)的影响

不同大写字母表示同一处理不同时间在P<0.05水平差异显著, 不同小写字母表示同一时间不同处理间在P<0.05水平差异显著。

Figure 2. Effects of nano-zero-valent iron (nZVI) on SOD activity (a), CAT activity (b), MDA content (c) and proline content (d) of earthworm

Different capital letters mean significant differences of a given nZVI treatment measured at different times at P<0.05 level. Different lowercase letters mean significant differences among nZVI treatments at same given obervation time at P<0.05 level.

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图 3 纳米零价铁(nZVI)对土壤细菌相对丰度的影响

Figure 3. Effects of nano-zero-valent iron (nZVI) on relative abundance of soil bacteria

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图 4 不同添加量纳米零价铁(nZVI) 和蚯蚓对土壤团聚体尺寸分布(A)和团聚体平均重量直径(MWD)(B)的影响

不同小写字母代表不同处理间差异显著(P<0.05)。Different lowercase letters mean significant differences among different treatments at P<0.05 level.

Figure 4. Effect of nano-zero-valent iron (nZVI) and earthworm on aggregate size distribution (A) and aggregate mean weight diameter (MWD, B) of soil

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表 1 纳米零价铁(nZVI)暴露45 d后蚯蚓指标间的相关分析(R值)

Table 1. Correlation analysis of earthworm indicators after 45 days of exposure to nano-zero-valent iron (nZVI) (R value)

指标 Index	存活率 Survival rate	生物量减少量 Reduction of biomass	CAT活性 CAT activity	SOD活性 SOD activity	MDA含量 MDA content	脯氨酸含量 Proline content
存活率 Survival rate	1
生物量减少量 Reduction of biomass	−0.642^**	1
CAT活性 CAT activity	−0.192	0.245	1
SOD活性 SOD activity	0.017	−0.102	−0.080	1
MDA含量 MDA content	0.059	−0.084	−0.143	−0.032	1
氨酸含量 Proline content	0.198	−0.266	−0.161	−0.303	−0.029	1
表示在 P<0.01(双尾)显著相关。 indicates significant correlation at P<0.01 (double tails).

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表 2 不同添加量纳米零价铁(nZVI)和蚯蚓对土壤细菌丰度和多样性的影响

Table 2. Effects of nano-zero-valent iron (nZVI) on abundance and diversity of soil bacteria (16S rRNA gene) (97% similarity level)

蚯蚓 Earthworm	nZVI添加量 nZVI rate (%)	香农指数 Shannon	辛普森指数 Simpson	Chao	Ace
无 No	0	9.4873±0.3169a	0.9798±0.0010a	2915.06±545.16a	2940.93±570.35a
	0.05	9.4325±0.2324a	0.9797±0.0007a	2885.51±323.55a	2916.06±337.59a
	0.25	9.4387±0.3604a	0.9796±0.0012a	2771.03±523.41a	2783.71±561.79a
	0.50	9.5352±0.2096a	0.9799±0.0006a	3056.69±301.52a	3090.94±320.31a
有 Exist	0	9.5499±0.0525a	0.9800±0.0002a	3157.40±104.32a	3204.63±107.87a
	0.05	9.5771±0.0521a	0.9801±0.0002a	3197.37±65.50a	3242.72±64.76a
	0.25	9.5796±0.0706a	0.9801±0.0001a	3113.03±91.71a	3156.79±97.9a
	0.50	9.5639±0.0606a	0.9800±2.3E-05a	3056.62±154.26a	3089.67±152.81a
“a”表示不同处理无显著差异(P>0.05)。“a” represents no significant difference among different treatments at P>0.05 level.

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表 3 纳米零价铁(nZVI)胁迫下蚯蚓活动对土壤化学性质的影响

Table 3. Effects of earthworm activities on soil chemical properties under nano-zero-valent iron (nZVI) stress

蚯蚓 Earthworm	nZVI添加量 nZVI rate (%)	有机质 Organic matter (g∙kg⁻¹)	全磷 Total phosphorus (g∙kg⁻¹)	全氮 Total nitrogen (g∙kg⁻¹)	碱解氮 Alkali-hydrolyzable nitrogen (mg∙kg⁻¹)	速效磷 Available phosphorus (mg∙kg⁻¹)
无 No	0	114.78±16.59a	1.15±0.30ab	3.55±0.2abc	395.68±48.23a	446.22±13.41c
	0.05	120.64±13.44a	1.24±0.52ab	3.51±0.37abc	346.56±45.55ab	472.28±9.02bc
	0.25	108.27±29.05ab	1.45±0.36a	3.70±0.45ab	368.71±62.44a	452.50±30.30bc
	0.50	109.13±9.93ab	1.32±0.15ab	3.93±0.57a	292.28±51.95b	448.62±33.61c
有 Exist	0	103.76±11.52ab	1.28±0.12ab	3.16±0.22c	392.92±38.11a	491.53±23.85b
	0.05	114.70±9.33a	0.98±0.40b	3.39±0.17bc	352.70±42.26ab	470.14±43.62bc
	0.25	109.44±6.1ab	1.21±0.38ab	3.29±0.19bc	365.46±54.99ab	490.86±24.15b
	0.50	88.29±25.41b	1.19±0.07ab	3.28±0.2bc	336.54±98.1ab	540.84±50.45a
同列不同小写字母表示不同处理(蚯蚓+nZVI添加量)间差异显著(P<0.05)。 Different lowercase letters in the same column represent significant differences among different treatments of nZVI and earthworm at P<0.05 level.

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表 4 纳米零价铁(nZVI)胁迫下蚯蚓活动对土壤质量的双因素方差分析

Table 4. Two factor analysis of variance of earthworm activity on soil quality under nano-zero-valent iron (nZVI) stress (P values)

指标 Index	nZVI (N)	df	蚯蚓 Earthworm (E)	df	E × N	df
大团聚体质量比 Mass ratio of macroaggregates	6.998^**	3	42.990^**	1	1.353^*	2
小团聚体质量比 Mass ratio of microaggregates	4.750^**	3	12.468^***	3	0.221^ns	2
黏土质量比 Mass ratio of clay	0.091^ns	1	0.214^ns	1	1.711^ns	1
有机质含量 Organic matter	2.512^ns	3	3.499^ns	1	0.893^ns	3
全氮含量 Total nitrogen	1.182^ns	3	17.075^***	1	1.282^ns	3
全磷含量 Total phosphorus	0.907^ns	3	1.689^ns	1	0.959^ns	3
碱解氮含量 Alkali-hydrolyzable nitrogen	3.999^**	3	0.440^ns	1	0.453^ns	3
速效磷含量 Available phosphorus	1.710^ns	3	21.911^***	1	4.341^**	3
平均重量直径 Average weight diameter	3.693^ns	1	24.911^***	1	0.001^ns	1
ns: P>0.05; : P ≤0.05; : P≤0.01; **: P≤0.001.

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