鸭跖草在不同土壤中对铜污染的响应

发布时间：2019-05-08 19:15

【摘要】：本研究主要解决以下三个问题：普通鸭跖草(即非矿区采集,且未经驯化的鸭跖草)对土壤铜耐受和富集能力；鸭跖草对铜污染环境的响应机理；普通鸭跖草修复铜污染土壤的可行性。本研究中进行了两种不同土壤加铜的盆栽鸭跖草试验,观察了鸭跖草在不同土壤中的生长状况,分析了鸭跖草养分含量和铜含量,并分析两种不同土壤的铜形态,结果表明,土壤性质和铜水平显著影响鸭跖草的生长、生理指标、养分含量和铜含量,鸭跖草生长和土壤加铜也影响土壤铜的形态与土壤理化性质,酸性土壤中铜的胁迫更强。通过盆栽实验和化学分析可知：(1)潮土中普通鸭跖草对土壤铜的耐受和富集能力在加铜浓度低于200 mg/kg时较好,鸭跖草铜富集量在50 mg/kg时达到最大值,当加铜浓度较高时,铜胁迫作用较为明显,鸭跖草的铜耐受和富集能力减弱；红壤中普通鸭跖草对土壤铜的耐受和富集能力非常有限,当加铜浓度高于50 mg/kg时,植株逐步衰弱直至死亡,但这并不能否定其在低浓度铜污染土壤中的铜耐受和富集力。(2)鸭跖草通过提高体内酶活性、叶绿素含量等方法抵抗重金属毒性,或吸收更多的养分以使自身更加茂盛,从而提高植株对铜污染环境的耐性。(3)随着加铜浓度的提高,弱酸可提取态铜含量与有效铜含量的变化趋势基本一致,说明土壤弱酸可提取态铜对有效铜含量具有重要意义,当加铜浓度为50 mg/kg时土壤中弱酸可提取态铜分配系数最低,为19.40%,证明普通(非矿区采集且未经驯化)鸭跖草在铜污染程度不太严重的情况下,不但可以吸收土壤中的铜来达到生物修复效果,还可以通过将土壤中的铜转化为不易被植物吸收的形态来达到减轻土壤污染,保护土壤生态环境,降低土壤中铜对作物的危害的目的。综合本研究的一系列结果可知,在潮土中,普通鸭跖草修复铜污染土壤的可行性较高,至少500 mg/kg加铜浓度下可以存活并吸收和转化土壤中的有效铜,但在红壤中,普通鸭跖草修复铜污染土壤的效果欠佳,植株难以生存,对治理红壤中较高浓度的铜污染意义不大。
[Abstract]:In this study, the following three problems were solved: the tolerance and enrichment of copper in soil, the response mechanism of common herbage to copper pollution, and the non-acclimated and non-acclimated ones, which was not collected in mining area, and the mechanism of response to copper pollution was also discussed in this study. Feasibility of remediation of copper-contaminated soil by common alpinia vulgaris. In this study, the pot experiment of two different soils with copper addition was carried out to observe the growth status, nutrient content and copper content in different soils, and to analyze the copper speciation in two different soils, and the results showed that: (1) the growth status of Dactyceps canadensis in different soil was observed, and the content of copper in two different soils was also analyzed. Soil properties and copper level significantly affected the growth, physiological index, nutrient content and copper content, and the growth and soil copper addition also affected the form and physical and chemical properties of soil copper. The stress of copper in acid soil was stronger than that in acid soil. Through pot experiment and chemical analysis, it was found that: (1) the tolerance and enrichment ability of common plantlets to soil copper was better when the concentration of copper was less than 200 mg/kg, and the maximum copper concentration was reached when the concentration of copper was 50 mg/kg. When the concentration of copper was higher, the effect of copper stress was more obvious, and the ability of tolerance and enrichment of copper was weakened. The tolerance and enrichment of copper in red soil was very limited. When the concentration of copper was higher than 50 mg/kg, the plant gradually weakened and died. But this does not negate its copper tolerance and enrichment in low-concentration copper-contaminated soils. (2) Duck metatarsal resists heavy metal toxicity by increasing enzyme activity and chlorophyll content in the body, or absorbs more nutrients to make itself more prosperous. (3) with the increase of copper concentration, the change trend of weak acid extractable copper content and available copper content was basically the same as that of available copper content. The results show that the extractable copper in soil is of great significance to the available copper content. When the concentration of copper is 50 mg/kg, the partition coefficient of weak acid extractable copper in soil is the lowest (19.40%). It is proved that the common (non-mining area collected and unacclimated) metatarsus can not only absorb copper from the soil to achieve the bioremediation effect when the copper pollution is not too serious. The purpose of reducing soil pollution, protecting soil ecological environment and reducing the harm of copper in soil to crops can also be achieved by transforming the copper in soil into a form which is not easily absorbed by plants. According to a series of results obtained in this study, it was found that it was feasible to repair copper-contaminated soil in tidal soil. At least 500 mg/kg of copper concentration could survive, absorb and transform available copper in soil, but in red soil, it was found that it was feasible to restore copper-contaminated soil at least 500 mg/kg, but in red soil, the available copper could be absorbed and transformed. It is difficult for plants to survive in the remediation of copper contaminated soil by common plantlets, which is of little significance to the treatment of copper pollution in red soil at a higher concentration.
【学位授予单位】：湖北大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X53

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