| 沈松蓉,陈云,康茜琳,向媛羚,耿育红,张伟,韩颖.寡氧单胞菌、水稻秸秆和蚯蚓协同修复Cr(Ⅵ)污染土壤[J].农业环境科学学报,2023,42(11):2440-2452. |
| 寡氧单胞菌、水稻秸秆和蚯蚓协同修复Cr(Ⅵ)污染土壤 |
| Synergistic remediation of Cr(Ⅵ)-contaminated soil by Stenotrophomonas sp., rice straw, and earthworms |
| 投稿时间：2023-03-07 |
| DOI：10.11654/jaes.2023-0165 |
| 中文关键词: Cr 寡氧单胞菌 水稻秸秆 蚯蚓 土壤团聚体 |
| 英文关键词: Cr Stenotrophomonas sp. rice straw earthworm soil aggregate |
| 基金项目:国家科技重大专项项目(2019YFC1805900)；四川省重大科技专项项目(2020YFH0128)；西南科技大学博士基金项目(14zx7120)；四川省自然科学基金项目(2022NSFSC1223) |
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| 中文摘要: |
| 为探究水稻秸秆和蚯蚓联合抗Cr细菌对Cr污染土壤的修复效果和机制,本研究通过室内模拟试验探讨细菌(寡氧单胞菌,Stenotrophomonas sp.,F)、水稻秸秆(S)、细菌+水稻秸秆(SF)、水稻秸秆+蚯蚓(赤子爱胜蚓,Eisenia foetida,SE)和细菌+水稻秸秆+蚯蚓(SFE)对50、300 mg·kg-1 Cr(Ⅵ)污染土壤的修复效果,生物有效态Cr的变化及总Cr和Cr(Ⅵ)在各粒径团聚体中的分布。结果表明:在试验早、中、后期各处理的总Cr和Cr(Ⅵ)去除率逐渐增加,在50、300 mg·kg-1 Cr(Ⅵ)暴露后期SFE处理的总Cr和Cr(Ⅵ)去除率最高,其总Cr去除率分别为35.68%、35.29%,Cr(Ⅵ)去除率分别为99.28%、75.33%。SFE处理显著降低了土壤氧化还原电位,增加了土壤pH和有机质含量,并促进了微团聚体凝聚胶结为大团聚体。在0、50、300 mg·kg-1 Cr(Ⅵ)暴露下SE处理大团聚体的占比最高,与CK相比分别增加了14.57、9.51、9.85个百分点,与SFE相比分别增加了3.73、4.09、3.28个百分点。各处理对Cr化学形态的影响为SFE>SF>SE>S>F,在整个试验过程中除F处理外,其余处理中各化学形态的占比都随试验时间的延长而稳定变化。与CK相比,在50、300 mg·kg-1 Cr(Ⅵ)暴露后期SFE处理中可交换态的占比分别降低了35.55、21.02个百分点,残渣态的占比分别增加了22.45、12.51个百分点。总Cr主要分布在大团聚体中,Cr(Ⅵ)主要分布在微团聚体中,所有处理各粒径团聚体中的总Cr和Cr(Ⅵ)含量都随试验时间的延长而降低,SFE处理显著降低了大团聚体中总Cr和微团聚体中Cr(Ⅵ)的含量。研究表明,在50、300 mg·kg-1 Cr(Ⅵ)暴露下水稻秸秆、蚯蚓和寡氧单胞菌协同处理显著增加了土壤总Cr和Cr(Ⅵ)的去除率,降低了生物有效态Cr的占比并改善了Cr在团聚体中的分布。 |
| 英文摘要: |
| This study aimed to understand the remediation effect and mechanism of rice straw and earthworm combined with Cr-resistant bacteria on Cr bioavailability and its distribution in soil aggregates. This study explored the remediation effect of Stenotrophomonas sp.(F), rice straw(S), bacteria + rice straw (SF), rice straw + earthworm(Eisenia foetida,SE), and bacteria + rice straw + earthworms (SFE) under 50 mg·kg-1 and 300 mg·kg-1 Cr(Ⅵ)-contaminated soil, and changes in the bioavailability of Cr and the distribution of total Cr and Cr(Ⅵ) in soil aggregates through indoor analog experiment. The results showed that the total Cr and Cr(Ⅵ) removal rates of each treatment steadily increased in the early, middle, and late stages of the experiment. The total Cr and Cr(Ⅵ) removal rates of the SFE treatment were the highest in the later stages of 50 mg·kg-1 and 300 mg·kg-1 Cr(Ⅵ) exposure, with total Cr removal rates of 35.68% and 35.29%, respectively, while the removal rates of Cr(Ⅵ) were 99.28% and 75.33%, respectively. The SFE treatment significantly reduced soil reduction potential, increased soil pH and organic matter content, and promoted the aggregation of micro-aggregates into large aggregates. The proportion of large aggregates treated with SE was the highest, increasing by 14.57, 9.51, and 9.85 percentage points compared to the CK, and 3.73, 4.09, and 3.28 percentage points compared to the SFE, respectively, under 0, 50 mg·kg-1, and 300 mg·kg-1 Cr(Ⅵ) exposure. The influence of each treatment on the chemical form of chromium was as follows:SFE>SF>SE>S>F. Except for F, the proportion of various chemical forms of Cr in all other treatments steadily changed with the extension of the experimental time throughout the entire experimental process. Compared with the CK, in the SFE treatment after 50 mg·kg-1 and 300 mg·kg-1 Cr(Ⅵ) exposure, the proportion of the exchangeable state decreased by 35.55 percentage points and 21.02 percentage points, respectively, and the residual state increased by 22.45 percentage points and 12.51 percentage points, respectively. Total Cr was mainly distributed in large-aggregates, while Cr(Ⅵ) was mainly distributed in micro-aggregates, and the total Cr and Cr(Ⅵ) concentrations in aggregates of all particle sizes decreased with time. The SFE treatment significantly reduced the accumulation of total Cr and Cr(Ⅵ) in large and micro-aggregates. The results indicate that the synergistic treatment of rice straw, earthworm, and Stenotrophomonas sp. significantly increase the removal rates of total Cr and Cr(Ⅵ) in soil, reduce the proportion of bioavailable Cr, and improve the distribution of Cr in aggregates under exposure to 50 mg·kg-1 and 300 mg·kg-1 Cr(Ⅵ). |
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