铀及伴生重金属对富集植物根际土壤酶活的影响研究
发布时间：2018-10-17 07:27
【摘要】：本论文围绕放射性污染生物处理的主要目标,以苋科苋属反枝苋(A maranthus retroflexus L.)、锦葵科秋葵属黄秋葵(Abelmoschus esculentus L.)、菊科鬼针草属鬼针草(Bidens pilosa L.)和十字花科芸薹属印度芥菜(Brassica juncea L.)为试验材料,采用盆栽试验,研究了铀及伴生重金属与富集植物土壤酶活性的关系,探讨了鬼针草根际与非根际土壤酶活变化,以期筛选出评价土壤放射性和重金属污染的关键酶学指标,并为放射性和重金属污染土壤生物修复机理的研究提供参考。研究结果如下:(1)对比铀及伴生重金属污染条件下印度芥菜、反枝苋、鬼针草和黄秋葵根际土壤酶活性变化发现:土壤脲酶能指示铀、锰和汞污染的程度;土壤酸性磷酸酶能指示砷的污染程度,印度芥菜、鬼针草和黄秋葵根际土壤酸性磷酸酶与砷的相关性分别为:-0.996**、-0.935*、-0.974**;土壤蔗糖酶可以指示汞的污染程度,四种植物根际土壤蔗糖酶与汞的相关性分别为-0.894*、-0.913*、-0.926*、-0.817*;土壤脱氢酶可以指示铀和锰的污染程度,土壤脱氢酶与铀和锰和汞的相关性最高可以达到:-0.948**、-0.961**。(2)根际土壤脲酶活性:印度芥菜黄秋葵鬼针草反枝苋;反枝苋根际土壤磷酸酶酶活值最高,其余三种植物根际土壤磷酸酶变化不显著;土壤蔗糖酶活性:黄秋葵印度芥菜反枝苋鬼针草;土壤脱氢酶活性:鬼针草印度芥菜反枝苋黄秋葵。(3)在单一及复合重金属处理下,鬼针草对不同土壤酶的提升作用为:磷酸酶脱氢酶蔗糖酶脲酶。铀及伴生重金属复合处理下,根际酶活更高,蔗糖酶可以用作U、Cd、Pb、As复合污染的重要指示酶。(4)铀及伴生重金属处理下显著抑制鬼针草株高和地上部分干重,随着浓度的增加抑制作用增强。而低浓度处理对鬼针草地下部分生物量的抑制作用比高浓度显著;U、Cd、Pb、As对鬼针草地下部分的最大抑制率分别是51.12%、31.58%、29.62%、31.17%。U、Cd、Pb、As等在一定浓度范围内对鬼针草光合作用强度、叶绿素荧光参数和叶绿素的影响不显著,但铀和镉对植物光合性能的毒害作用大于铅和砷。
[Abstract]:In this paper, the main target of biological treatment of radioactive pollution was studied with (A maranthus retroflexus L.), (Abelmoschus esculentus L.), and (Bidens pilosa L.). And (Brassica juncea L.) of Brassica in Cruciferae In this paper, the relationship between uranium and associated heavy metals and the enzyme activity of enriched plant soil was studied, and the changes of enzyme activity in rhizosphere and non-rhizosphere soil of Pinus nigra were studied by pot experiment. In order to screen out the key enzyme indexes to evaluate soil radioactive and heavy metal pollution, and to provide reference for the study of bioremediation mechanism of radioactive and heavy metal contaminated soil. The results are as follows: (1) comparing the changes of soil enzyme activities of Indian mustard, amaranth, Phanicularia nigra and Okra in the condition of uranium and associated heavy metal pollution, we found that soil urease can indicate the degree of contamination of uranium, manganese and mercury; Soil acid phosphatase can indicate the degree of arsenic pollution, and the correlation between soil acid phosphatase and arsenic in the rhizosphere of Indian mustard, Phanicularia nigra and okra is -0.996% -0.935% -0.974%, respectively, and soil sucrase can indicate the degree of mercury pollution. The correlation between sucrase and mercury in rhizosphere soil of the four plants was -0.894ka-0.913 ~ + -0.926 ~ + -0.817 ~ 0.17, respectively, and soil dehydrogenase could indicate the degree of contamination of uranium and manganese. Soil dehydrogenase had the highest correlation with uranium, manganese and mercury. (2) the soil urease activity of rhizosphere soil was the highest, and the activity of phosphatase was the highest in rhizosphere soil. The activity of soil sucrose enzyme in the rhizosphere of the other three plants was not significant; the activity of soil sucrase was as follows: Indian mustard reverse amaranth; soil dehydrogenase activity: Indian mustard reverse amaranth okra. (3) under single and complex heavy metal treatments, The promotion effect of Phanicularia chinensis on different soil enzymes was as follows: phosphatase dehydrogenase, sucrase urease. The rhizosphere enzyme activity of uranium and associated heavy metals was higher, sucrase could be used as an important indicator of the compound pollution of UroCdCd-PbPbAs. (4) uranium and associated heavy metals significantly inhibited the plant height and aboveground dry weight. The inhibitory effect was enhanced with the increase of concentration. However, the inhibitory effect of low concentration treatment on the biomass of the underground part of Phellodendron japonicus was significantly higher than that of the high concentration, and the maximum inhibition rate of UCD PbAs on the underground part of Phellodendron japonicus was 51.122.31.58 and 29.620.31.17% respectively. The effects of chlorophyll fluorescence parameters and chlorophyll were not significant, but the toxicity of uranium and cadmium to photosynthetic performance of plants was greater than that of lead and arsenic.
【学位授予单位】：西南科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X173;X53
，
本文编号：2275960
[Abstract]:In this paper, the main target of biological treatment of radioactive pollution was studied with (A maranthus retroflexus L.), (Abelmoschus esculentus L.), and (Bidens pilosa L.). And (Brassica juncea L.) of Brassica in Cruciferae In this paper, the relationship between uranium and associated heavy metals and the enzyme activity of enriched plant soil was studied, and the changes of enzyme activity in rhizosphere and non-rhizosphere soil of Pinus nigra were studied by pot experiment. In order to screen out the key enzyme indexes to evaluate soil radioactive and heavy metal pollution, and to provide reference for the study of bioremediation mechanism of radioactive and heavy metal contaminated soil. The results are as follows: (1) comparing the changes of soil enzyme activities of Indian mustard, amaranth, Phanicularia nigra and Okra in the condition of uranium and associated heavy metal pollution, we found that soil urease can indicate the degree of contamination of uranium, manganese and mercury; Soil acid phosphatase can indicate the degree of arsenic pollution, and the correlation between soil acid phosphatase and arsenic in the rhizosphere of Indian mustard, Phanicularia nigra and okra is -0.996% -0.935% -0.974%, respectively, and soil sucrase can indicate the degree of mercury pollution. The correlation between sucrase and mercury in rhizosphere soil of the four plants was -0.894ka-0.913 ~ + -0.926 ~ + -0.817 ~ 0.17, respectively, and soil dehydrogenase could indicate the degree of contamination of uranium and manganese. Soil dehydrogenase had the highest correlation with uranium, manganese and mercury. (2) the soil urease activity of rhizosphere soil was the highest, and the activity of phosphatase was the highest in rhizosphere soil. The activity of soil sucrose enzyme in the rhizosphere of the other three plants was not significant; the activity of soil sucrase was as follows: Indian mustard reverse amaranth; soil dehydrogenase activity: Indian mustard reverse amaranth okra. (3) under single and complex heavy metal treatments, The promotion effect of Phanicularia chinensis on different soil enzymes was as follows: phosphatase dehydrogenase, sucrase urease. The rhizosphere enzyme activity of uranium and associated heavy metals was higher, sucrase could be used as an important indicator of the compound pollution of UroCdCd-PbPbAs. (4) uranium and associated heavy metals significantly inhibited the plant height and aboveground dry weight. The inhibitory effect was enhanced with the increase of concentration. However, the inhibitory effect of low concentration treatment on the biomass of the underground part of Phellodendron japonicus was significantly higher than that of the high concentration, and the maximum inhibition rate of UCD PbAs on the underground part of Phellodendron japonicus was 51.122.31.58 and 29.620.31.17% respectively. The effects of chlorophyll fluorescence parameters and chlorophyll were not significant, but the toxicity of uranium and cadmium to photosynthetic performance of plants was greater than that of lead and arsenic.
【学位授予单位】：西南科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X173;X53
，
本文编号：2275960
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