【摘要】：本論文圍繞放射性污染生物處理的主要目標,以莧科莧屬反枝莧(A maranthus retroflexus L.)、錦葵科秋葵屬黃秋葵(Abelmoschus esculentus L.)、菊科鬼針草屬鬼針草(Bidens pilosa L.)和十字花科蕓薹屬印度芥菜(Brassica juncea L.)為試驗材料,采用盆栽試驗,研究了鈾及伴生重金屬與富集植物土壤酶活性的關(guān)系,探討了鬼針草根際與非根際土壤酶活變化,以期篩選出評價土壤放射性和重金屬污染的關(guān)鍵酶學指標,并為放射性和重金屬污染土壤生物修復機理的研究提供參考。研究結(jié)果如下:(1)對比鈾及伴生重金屬污染條件下印度芥菜、反枝莧、鬼針草和黃秋葵根際土壤酶活性變化發(fā)現(xiàn):土壤脲酶能指示鈾、錳和汞污染的程度;土壤酸性磷酸酶能指示砷的污染程度,印度芥菜、鬼針草和黃秋葵根際土壤酸性磷酸酶與砷的相關(guān)性分別為:-0.996**、-0.935*、-0.974**;土壤蔗糖酶可以指示汞的污染程度,四種植物根際土壤蔗糖酶與汞的相關(guān)性分別為-0.894*、-0.913*、-0.926*、-0.817*;土壤脫氫酶可以指示鈾和錳的污染程度,土壤脫氫酶與鈾和錳和汞的相關(guān)性最高可以達到:-0.948**、-0.961**。(2)根際土壤脲酶活性:印度芥菜黃秋葵鬼針草反枝莧;反枝莧根際土壤磷酸酶酶活值最高,其余三種植物根際土壤磷酸酶變化不顯著;土壤蔗糖酶活性:黃秋葵印度芥菜反枝莧鬼針草;土壤脫氫酶活性:鬼針草印度芥菜反枝莧黃秋葵。(3)在單一及復合重金屬處理下,鬼針草對不同土壤酶的提升作用為:磷酸酶脫氫酶蔗糖酶脲酶。鈾及伴生重金屬復合處理下,根際酶活更高,蔗糖酶可以用作U、Cd、Pb、As復合污染的重要指示酶。(4)鈾及伴生重金屬處理下顯著抑制鬼針草株高和地上部分干重,隨著濃度的增加抑制作用增強。而低濃度處理對鬼針草地下部分生物量的抑制作用比高濃度顯著;U、Cd、Pb、As對鬼針草地下部分的最大抑制率分別是51.12%、31.58%、29.62%、31.17%。U、Cd、Pb、As等在一定濃度范圍內(nèi)對鬼針草光合作用強度、葉綠素熒光參數(shù)和葉綠素的影響不顯著,但鈾和鎘對植物光合性能的毒害作用大于鉛和砷。
[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.
【學位授予單位】：西南科技大學
【學位級別】：碩士
【學位授予年份】：2016
【分類號】：X173;X53
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本文編號：2275960