本文選題：鋅鎘污染土壤 + 田間試驗　； 參考：《貴州大學(xué)》2015年碩士論文

【摘要】：重金屬污染土壤植物修復(fù)技術(shù)因其固有的優(yōu)越性而具有廣泛的應(yīng)用潛力,但該技術(shù)應(yīng)用往往需要多次種植植物進行連續(xù)修復(fù)。修復(fù)過程中土壤重金屬和植物吸收重金屬變化將顯著影響修復(fù)效率,且較長修復(fù)時間與農(nóng)田土壤利用相矛盾。本論文以有色金屬冶煉以及污泥有機肥長期農(nóng)用導(dǎo)致的重金屬污染土壤為對象,利用鋅鎘超積累植物伴礦景天(Sedum plumbizincicol a)及農(nóng)作物開展田間連續(xù)修復(fù)和水分模擬試驗,探討長期田間連續(xù)修復(fù)下污染土壤鋅鎘和植物鋅鎘變化特征;探索適宜的生產(chǎn)和修復(fù)同時進行的種植模式和水分調(diào)控措施,為鋅鎘污染土壤進行安全生產(chǎn)的同時實現(xiàn)高效吸取修復(fù)提供理論依據(jù)。主要研究結(jié)果如下:1.連續(xù)八年開展伴礦景天與玉米(或高粱)套作田間試驗,探討長期修復(fù)下植物及土壤中鋅鎘變化。結(jié)果表明,田間長期原位修復(fù)能顯著降低農(nóng)田土壤的鋅鎘濃度,其中套作處理下土壤鎘濃度從3.50±0.49 mg kg-1降低到0.55±0.44 mg kg-1,從而使土壤中鎘低于國家土壤環(huán)境質(zhì)量(GB15618-1995)三級標(biāo)準(zhǔn)。與2006年未修復(fù)土壤相比,玉米(高粱)單作、伴礦景天單作、玉米與伴礦景天間作處理,對污染土壤中鋅鎘的總?cè)コ迯?fù)效率分別達(dá)7.2,13.7,18.8%;40.9,71.9和85.4%,即伴礦景天與玉米間作可提高植物吸取修復(fù)效率,且玉米籽粒中鎘濃度符合國家食品安全標(biāo)準(zhǔn),可實現(xiàn)污染土壤的“邊生產(chǎn)邊修復(fù)”。2.在污泥有機肥長期農(nóng)用土壤上種植伴礦景天,與常規(guī)的玉米-小麥-胡蘿卜輪作處理比較,田間試驗探討了污泥有機肥長期施用導(dǎo)致的重金屬污染土壤上農(nóng)產(chǎn)品的污染風(fēng)險和連續(xù)植物修復(fù)效率。結(jié)果表明,長期污泥農(nóng)用土壤上農(nóng)作物和超積累植物生長良好。與對照相比,“玉米-小麥-胡蘿卜輪作”處理作物中鋅鎘濃度有所上升,且小麥、胡蘿卜中鎘濃度超過國家食品安全標(biāo)準(zhǔn)。伴礦景天處理下土壤中重金屬顯著降低,修復(fù)效率達(dá)到56.0%,而繼續(xù)施用污泥情況下超積累植物的修復(fù)效率仍可達(dá)48.0%。證明在施用污泥條件下,種植伴礦景天和玉米,能夠?qū)崿F(xiàn)污泥安全處理、促進農(nóng)作物生長和超積累植物高效修復(fù)的三重目標(biāo)。3.土壤水分變化可顯著改變土壤性質(zhì)進而影響土壤重金屬有效性。本試驗通過測定土壤溶液和采用薄層凝膠梯度法(DGT)表征的水分變化過程中土壤重金屬有效性的變化特征。結(jié)果表明,土壤干燥可顯著降低DGT表征的重金屬有效性。在農(nóng)業(yè)生產(chǎn)中可通過適當(dāng)水分管理措施改變土壤重金屬的有效性,從而調(diào)節(jié)農(nóng)作物和超積累植物對重金屬吸收。
[Abstract]:The phytoremediation technology of heavy metal contaminated soil has wide application potential because of its inherent advantages, but the application of this technique often requires the continuous remediation of plants planted many times. The changes of heavy metals uptake by soil and plants during remediation will significantly affect the remediation efficiency, and the longer remediation time is contradictory to the utilization of farmland soil. In this paper, the heavy metal contaminated soil caused by non-ferrous metal smelting and sludge organic fertilizer for a long time was used to carry out continuous remediation and water simulation experiments in the field by using Zn and CD superaccumulative plant plumbizincicol a and crops. To explore the variation characteristics of Zn and CD in contaminated soil and plants under long-term continuous remediation in the field, and to explore the suitable planting mode and water control measures at the same time of production and remediation. It provides a theoretical basis for the safe production of zinc and cadmium contaminated soil and the realization of high efficiency absorption and remediation at the same time. The main results are as follows: 1. For eight consecutive years, a field experiment was carried out to study the changes of Zn and CD in plant and soil under long-term remediation with maize (or sorghum). The results showed that long-term in situ remediation could significantly reduce the concentration of Zn and CD in farmland soil. The soil cadmium concentration decreased from 3.50 鹵0.49 mg kg-1 to 0.55 鹵0.44 mg kg-1 under intercropping treatment, which resulted in the cadmium in soil lower than the third grade standard of National soil Environmental quality (GB15618-1995). Compared with the unrepaired soil in 2006, the maize (sorghum) monoculture, the intercropping of maize and the intercropping of the mined-linked Jingtian were treated. The total removal and remediation efficiency of Zn and CD in contaminated soil were 7.2 ~ 13.718.8% ~ 40.9 ~ 71.9 and 85.4, respectively. That is, the intercropping of Jingtian and corn could improve the recovery efficiency of plant absorption, and the cadmium concentration in corn grain was in line with the national food safety standard, and the total remediation efficiency of Zn ~ (2 +) and CD ~ (2 +) in maize grain was in accordance with the national food safety standard. Can achieve contaminated soil "production while remediation". 2. Compared with the conventional maize, wheat and carrot rotation treatment, the soil planted with sludge organic fertilizer for a long period of time in agriculture was compared with the conventional maize, wheat and carrot rotation treatment. Field experiments were conducted to investigate the risk of agricultural products pollution and the efficiency of continuous phytoremediation of heavy metal contaminated soil caused by long-term application of sludge organic fertilizer. The results showed that the crops and super-accumulative plants grew well on the soil of long-term sludge. Compared with the control, the concentration of Zn and CD in the maize, wheat and carrot rotation increased, and the cadmium concentration in wheat and carrot exceeded the national food safety standard. The heavy metals in the soil decreased significantly and the remediation efficiency reached 56.0 under the treatment of Jingtian mine, but the remediation efficiency of the superaccumulative plants was still 48.0 under the condition of continued application of sludge. It was proved that under the condition of sludge application, the triple target of high efficiency remediation of crops growth and superaccumulation could be achieved by planting Jingtian and maize. The change of soil moisture can significantly change the properties of soil and then affect the availability of heavy metals in soil. In this experiment, the characteristics of the availability of heavy metals in soil were determined by means of soil solution and TLC Gel gradient method (TGG). The results showed that soil drying could significantly reduce the availability of heavy metals characterized by DGT. In agricultural production, the availability of heavy metals in soil can be changed by appropriate water management measures, thus regulating the absorption of heavy metals by crops and superaccumulative plants.
【學(xué)位授予單位】：貴州大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：X53;X173
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本文編號：1868372