摘要: |
本研究通过单种鹅掌藤Schefflera arboricola、单种团花Neolamarckia cadamba和混种团花与鹅掌藤的大根箱实验,跟踪分析表施2%(W/W)污泥后3个月(2020年9、10和11月)的鲜叶和凋落叶Cu、Zn、Cd和Hg含量以及凋落叶产量变化,分析鲜叶与凋落叶重金属含量关系以及凋落叶重金属回归量变化。结果表明:(1)污泥施用下团花鲜叶和凋落叶Cu含量均显著高于鹅掌藤,而Zn和Cd含量均显著低于鹅掌藤。(2)鹅掌藤鲜叶Zn含量在11月最低,而Hg含量在11月最高。(3)单种和混种团花鲜叶Zn、Cd和Hg含量在11月最高。(4)混种的团花凋落叶Hg含量随污泥施用时间延长而显著增加,而Cu、Zn和Cd含量变化不明显。(5)9月和11月鹅掌藤鲜叶Cd含量均与凋落叶Hg和Cd含量显著正相关。(6)鹅掌藤和团花凋落叶产量及Cu、Zn、Cd和Hg回归量分别在污泥施用1个月后(9月)和2个月后(10月)最高。综上,污泥施用时间对团花和鹅掌藤的鲜叶重金属含量影响较大,而对凋落叶重金属含量影响较小;鹅掌藤鲜叶Cd含量与凋落叶Cd和Hg含量存在正相关;鹅掌藤和团花分别在污泥施用1个月后(9月)和2个月后(10月)凋落叶重金属污染风险较高。本研究将为污泥园林利用和凋落叶的合理处置提供借鉴。 |
关键词: 污泥资源利用,重金属,园林植物,凋落叶,混种 |
DOI:10.11931/guihaia.gxzw202211032 |
分类号: |
基金项目:国家自然科学(42177011, 41807112, 31971629);广东省自然科学(2021A1515011407, 2022A1515010909);广州市科技计划项目(202201010419)。 |
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The changes of heavy metal in fresh and litter leaves of Neolamarckia cadamba and Schefflera arboricola under sludge application |
Bao lian, Dong xiaoquan, Lai mingli, Zhu huijun, Wu jiaxi, Zeng shucai, Wu daoming
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华南农业大学
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Abstract: |
This study conducted a large root box experiment with Schefflera arboricola monoculture, Neolamarckia cadamba monoculture, and co-planting of S. arboricola and N. cadamba. The dynamic changes in Cu, Zn, Cd, and Hg content in fresh and litter leaves of S. arboricola and N. cadamba and their litter production were analyzed for three months (September, October, and November 2020 ) after the surface application of 2% (W/W) SS. The relationship between the HM content of fresh leaf and that of litter leaf and the changes in the HM return amount in leaf litter were further analyzed. The results were as follows: (1) N. cadamba had significantly higher Cu content in fresh and litter leaves than that of S. arboricola, while had significantly lower Zn and Cd contents than those of S. arboricola. (2) The fresh leaf of S. arboricola had the lowest Zn content and the highest Hg content in November. (3) The fresh leaf of N. cadamba had the highest Zn, Cd, and Hg contents in November. (4) The Hg content in the litter leaf of co-planting of N. cadamba increased significantly with the time of SS application, while that of Cu, Zn, and Cd contents showed no significance. (5) The Cd content in fresh leaves was significantly and positively correlated with the Hg and Cd contents of leaf litter in S. arboricola in both September and November. (6) The highest yield of leaf litter and the highest return amount of Cu, Zn, Cd, and Hg in S. arboricola occurred one month after SS application (September), while those in N. cadamba occurred two months after SS application (October). In summary, the application time of SS showed a greater effect on the HM contents in fresh leaves of N. cadamba and S. arboricola than those in litter leaves. There was a positive correlation between the Cd content in the fresh leaf and the Cd and Hg contents in the litter leaf of S. arboricola. The HM pollution risk of the litter leaves of S. arboricola and N. cadamba was easy to occur in one month (September) and two months after SS application (October), respectively. This study will provide a reference for safe SS utilization and reasonable litter disposal in the landscape. |
Key words: Sewage sludge recycling, Heavy metal, Landscape plant, Leaf litter, Co-planting |