土壤调理剂对镉污染土壤修复及小叶榕生长影响研究

Study on the effect of soil conditioner on cadmium-contaminated soil remediation and growth of Ficus microcarpa

关键词:  土壤调理剂  小叶榕  Cd污染土壤  凹凸棒土  活性炭

Key words:  soil conditioners  Ficus microcarpa  Cd contaminated soil  attapulgite  activated carbon

摘要:

本研究以小叶榕（Ficus microcarpa）1年生幼苗为研究对象，采用重金属Cd污染土壤添加凹凸棒土（处理A）、活性炭（处理B）、竹炭（处理C）3种调理剂结合植物盆栽实验，揭示土壤调理剂对重金属Cd污染土壤性质及小叶榕生长的影响，为小叶榕结合调理剂协同修复重金属污染土壤提供理论依据。结果表明：3种土壤调理剂通过提高土壤pH值、有机质含量改善Cd污染土壤环境，利用自身结构性质通过吸附、离子交换等方式降低污染土壤中总Cd和有效态Cd含量，提升小叶榕修复重金属Cd污染土壤的能力；在3种土壤调理剂中，处理A（添加质量比5%凹凸棒土）在提升土壤pH值（处理A：7.69、处理B：6.10、处理C：6.06）、有机质含量（处理A：31.21 g·kg-1、处理B：28.78 g·kg-1、处理C：29.34 g·kg-1）方面高于其他处理，在降低土壤有效态Cd含量（处理A：0.17 mg·kg-1、处理B：0.22 mg·kg-1、处理C：0.20 mg·kg-1）、总Cd含量（处理A：0.68 mg·kg-1、处理B：0.77 mg·kg-1、处理C：0.73 mg·kg-1）及植物MDA含量（处理A：39.37 nmol·g-1、处理B：45.52 nmol·g-1、处理C：42.65 nmol·g-1）等方面优于其他处理。综合聚类分析表明，小叶榕结合凹凸棒土（质量比5%）、小叶榕结合活性炭（质量比5%）2种措施在促进小叶榕生长和修复Cd污染土壤方面表现更好。

Abstract:

In this study, 1-year-old seedlings of Ficus microcarpa were used as the experimental subjects. Three types of soil conditioners were added to soil contaminated with the heavy metal Cd: treatment A (attapulgite), treatment B (activated carbon), and treatment C (bamboo charcoal). Combined with plant pot experiments, the study aimed to reveal the effects of these soil conditioners on the properties of Cd-contaminated soil and the growth of F. microcarpa. The results provide a theoretical basis for the synergistic remediation of heavy metal-contaminated soil using F. microcarpa in combination with soil conditioners.The results showed that the three soil conditioners improved the environment of Cd-contaminated soil by increasing soil pH and organic matter content. They also reduced the total Cd and available Cd content in the contaminated soil through adsorption and ion exchange, leveraging their structural properties. This enhancement improved the ability of F. microcarpa to remediate Cd-contaminated soil. Among the three soil conditioners, treatment A (attapulgite at a 5% mass ratio) outperformed the other treatments in increasing soil pH (treatment A: 7.69; treatment B: 6.10; treatment C: 6.06), organic matter content (treatment A: 31.21 g·kg-1; treatment B: 28.78 g·kg-1; treatment C: 29.34 g·kg-1), and reducing soil available Cd content (treatment A: 0.17 mg·kg-1; treatment B: 0.22 mg·kg-1; treatment C: 0.20 mg·kg-1), total Cd content (treatment A: 0.68 mg·kg-1; treatment B: 0.77 mg·kg-1; treatment C: 0.73 mg·kg-1), and plant MDA content (treatment A: 39.37nmol·g-1; treatment B: 45.52 nmol·g-1; treatment C: 42.65 nmol·g-1).Comprehensive cluster analysis indicated that two approaches-F. microcarpa combined with attapulgite (5%) and F. microcarpa combined with activated carbon (5%)-performed better in promoting the growth of F. microcarpa and remediating Cd-contaminated soil.