Key Laboratory of Bio-resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, Sichuan, PR China.
Key Laboratory of Bio-resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, Sichuan, PR China.
Chemosphere. 2020 Jan;239:124706. doi: 10.1016/j.chemosphere.2019.124706. Epub 2019 Aug 31.
The remediation effect of organic acids in heavy metal contaminated soil was widely studied. However, the comprehensive evaluation of organic acids on micro-ecological environment in heavy metal contaminated soil was less known. Herein, this experiment was conducted to investigate the impact of malic acid, citric acid and oxalic acid on soil fertility, cadmium (Cd) speciation and ecotoxicity in contaminated soil. Especially, to evaluate the ecotoxicity of Cd, high-throughput sequencing was used to investigate the soil bacterial community structure and diversity after incubation with organic acids. The results showed that obvious changes in soil pH were not observed. Whereas, the contents of available phosphorus (Olsen-P) and alkali hydrolysable nitrogen (Alkeline-N) evidently increased with a significant difference. Furthermore, compared to control, the proportion of acetic acid-extractable Cd increased by 3.06-6.63%, 6.11-9.43% and 1.91-6.22% respectively in the groups amended with malic acid, citric acid and oxalic acid, which indicated that citric acid did better in improving the availability of Cd than malic acid and oxalic acid. In terms of biological properties, citric acid did best in bacteria count increase, enzyme activities and bacterial community structure improvement. Accordingly, these results provided a better understanding for the influence of organic acids on the micro-ecological environment in Cd contaminated soil, based on physicochemical and biological analysis.
有机酸对重金属污染土壤的修复效果得到了广泛研究。然而，有机酸对重金属污染土壤微生态环境的综合评价还知之甚少。本实验旨在研究苹果酸、柠檬酸和草酸对污染土壤肥力、镉形态和生态毒性的影响。特别是，为了评估镉的生态毒性，采用高通量测序技术研究了在有机酸孵育后土壤细菌群落结构和多样性的变化。结果表明，土壤 pH 值没有明显变化。然而，有效磷（Olsen-P）和碱解氮（Alkeline-N）的含量明显增加，且差异显著。此外，与对照相比，添加苹果酸、柠檬酸和草酸后，乙酸提取态镉的比例分别增加了 3.06%-6.63%、6.11%-9.43%和 1.91%-6.22%，这表明柠檬酸在提高镉的有效性方面优于苹果酸和草酸。在生物特性方面，柠檬酸在细菌计数增加、酶活性和细菌群落结构改善方面表现最好。因此，这些结果为基于理化和生物学分析的有机酸对 Cd 污染土壤微生态环境影响提供了更好的理解。
