不同種植密度對(duì)春小麥積累土壤重金屬的影響研究及人體健康風(fēng)險(xiǎn)評(píng)價(jià)
發(fā)布時(shí)間：2018-10-21 20:28
【摘要】：白銀地區(qū)是我國(guó)重要的重金屬采礦與冶煉基地,悠久的采礦歷史和過(guò)度的工農(nóng)業(yè)活動(dòng)使得該地區(qū)農(nóng)田土壤系統(tǒng)受到了嚴(yán)重的污染,其中以重金屬污染最為嚴(yán)重。土壤重金屬可通過(guò)土壤-植物系統(tǒng)在作物中積累,進(jìn)而通過(guò)食物鏈進(jìn)入到人體并對(duì)人體健康造成危害。雖然當(dāng)?shù)氐耐寥牢廴拘迯?fù)工作已在開(kāi)展中,但收效甚微。作為主要糧食作物的春小麥(Triticum aestivum)在當(dāng)?shù)乇粡V泛種植,但污染環(huán)境條件下,春小麥對(duì)土壤中重金屬的積累情況如何仍不清楚,長(zhǎng)期食用對(duì)當(dāng)?shù)鼐用窠】涤泻螡撛陲L(fēng)險(xiǎn)也未見(jiàn)詳細(xì)報(bào)道。因此,開(kāi)展污染環(huán)境條件下春小麥對(duì)土壤重金屬的積累效應(yīng)及其影響因素的研究,對(duì)當(dāng)?shù)剞r(nóng)作物安全生產(chǎn)和盡可能降低當(dāng)?shù)鼐用窠】碉L(fēng)險(xiǎn)具有重要意義。本研究選擇白銀四龍鎮(zhèn)東大溝沿岸農(nóng)田為研究地點(diǎn),以不同種植密度的春小麥為研究對(duì)象,通過(guò)測(cè)定研究地常見(jiàn)的重金屬銅(Cu)、鋅(Zn)、鉛(Pb)、鎘(Cd)的濃度以及土壤速效氮、速效磷和pH等因子,以及通過(guò)采集和測(cè)定春小麥各期(三葉期、分蘗期、拔節(jié)期、抽穗期、開(kāi)花期、灌漿期和成熟期)不同組織(根、莖、葉、穎殼和籽粒)中重金屬的濃度,旨在闡明當(dāng)?shù)卮盒←湶煌M織對(duì)重金屬的積累效應(yīng)及其影響因素、揭示春小麥不同組織對(duì)重金屬的積累隨生長(zhǎng)時(shí)期的變化規(guī)律、探尋通過(guò)增加種植密度來(lái)降低春小麥籽粒重金屬濃度和居民所受健康風(fēng)險(xiǎn)的可行性。研究結(jié)果顯示：1.白銀東大溝排污溝沿岸農(nóng)田土壤中Cu、Zn、Cd污染嚴(yán)重,遠(yuǎn)超過(guò)國(guó)家土壤安全標(biāo)準(zhǔn)限值(Cu 100 mg kg-1, Zn 300 mg kg-1, Cd 1 mg kg-1),而Pb濃度在上游土壤中超過(guò)安全標(biāo)準(zhǔn)限值(300 mg kg-1),下游相應(yīng)濃度則在安全濃度以?xún)?nèi)。白銀當(dāng)?shù)卮盒←溄M織中的重金屬濃度與土壤速效氮濃度呈顯著正相關(guān)(p0.05),與土壤速效磷濃度相關(guān)性不顯著(p0.05)。土壤重金屬的可交換態(tài)和碳酸鹽結(jié)合態(tài)處于較高水平,促進(jìn)了春小麥各組織尤其是籽粒中的重金屬濃度。2.在春小麥生長(zhǎng)的三葉期到分蘗期,小麥根、莖、葉中的重金屬濃度達(dá)到了峰值,然后逐漸下降。單株春小麥積累重金屬的量隨生長(zhǎng)時(shí)間增加而增加。春小麥各個(gè)組織積累重金屬的能力分別為：對(duì)Cu,根穎殼葉莖籽粒；對(duì)Zn,根籽粒葉穎殼莖；對(duì)Pb,根葉穎殼籽粒莖；對(duì)Cd,根葉莖穎殼籽粒。3.增加種植密度可以在一定程度上降低重金屬在春小麥組織尤其是Pb和Cd在籽粒中的積累,從而降低重金屬對(duì)當(dāng)?shù)鼐用窨赡茉斐傻慕】碉L(fēng)險(xiǎn),說(shuō)明增加種植密度可以作為當(dāng)?shù)卮盒←湼鼮榘踩纳a(chǎn)方式。4.隨著種植密度的增加,單位面積內(nèi)春小麥所積累的重金屬量有所下降,在種植密度最大時(shí)具有顯著降低,顯示在使用植物進(jìn)行土壤重金屬原位修復(fù)時(shí),植物或作物的種植密度是影響移除效果的關(guān)鍵因素之一綜上所述,白銀東大溝沿岸農(nóng)業(yè)區(qū)土壤受重金屬污染嚴(yán)重,生長(zhǎng)于其上的春小麥各組織中的重金屬濃度主要與土壤速效氮、土壤重金屬可交換態(tài)及碳酸鹽結(jié)合態(tài)的濃度相關(guān),且都呈正相關(guān)關(guān)系(p0.01)；春小麥對(duì)重金屬的積累能力具有組織差異性,并且會(huì)隨著春小麥的種植密度的增加和生長(zhǎng)期的延長(zhǎng)而降低；春小麥籽粒中重金屬積累濃度對(duì)當(dāng)?shù)鼐用窠】稻哂袧撛陲L(fēng)險(xiǎn),但是,可在不顯著降低產(chǎn)量的前提下,通過(guò)提高種植密度的方式降低這種風(fēng)險(xiǎn)。總之,本研究結(jié)果對(duì)長(zhǎng)期受重金屬污染的白銀農(nóng)業(yè)區(qū)春小麥安全生產(chǎn)及降低當(dāng)?shù)鼐用窠】碉L(fēng)險(xiǎn)具有參考意義。
[Abstract]:Baiyin region is an important heavy metal mining and smelting base in China. The long mining history and excessive industrial and agricultural activities have caused serious pollution to farmland soil system in this area, among which heavy metal pollution is the most serious. Soil heavy metals can accumulate in crops through soil-plant systems, and then enter the human body through the food chain and pose a hazard to human health. Although local soil pollution remediation efforts have been carried out, little success has been achieved. Spring wheat (spring wheat), which is the main food crop, has been widely cultivated locally, but the accumulation of heavy metals in soil under the condition of environmental pollution is still unclear, and the potential risks of long-term consumption to the health of local residents have not been reported in detail. Therefore, the research on the accumulation effect of spring wheat on soil heavy metals and its influencing factors under the condition of environmental pollution is of great significance to the safe production of local crops and to reduce the health risk of local residents as much as possible. In this study, we select the farmland as the research site in Donggugou, Baiyin, and study the concentration of heavy metal copper (Cu), zinc (Zn), lead (Pb), Cd (Cd) and quick-acting nitrogen in soil by measuring the common heavy metal copper (Cu), zinc (Zn), lead (Pb), Cd (Cd). The concentrations of heavy metals in different tissues (roots, stems, leaves, glumes and seeds) of spring wheat (root, stem, leaf, glume and kernel) are determined by collecting and measuring the factors such as phosphorus and pH, The effects of different tissues of spring wheat on the accumulation of heavy metals and their influencing factors are expounded, and the changes of the accumulation of heavy metals in different tissues of spring wheat with the growth period are revealed. To explore the feasibility of reducing the heavy metal concentration and health risk of spring wheat grains by increasing planting density. The results showed that: 1. The pollution of Cu, Zn and Cd in farmland soil along the Daogou sewage ditch of Baiyin is serious, far exceeding the national soil safety standard limit (Cu 100 mg kg-1, Zn 300 mg kg-1, Cd 1 mg kg-1), while the Pb concentration exceeds the safety standard limit value (300 mg kg-1) in the upstream soil. The downstream corresponding concentration is within the safe concentration. The concentration of heavy metals in the local spring wheat tissues of Baiyin was positively correlated with the soil available nitrogen concentration (P0.05). The exchangeable state of heavy metals in soil and the state of carbonate leaching are at a higher level, which promotes the concentration of heavy metals in the tissues of spring wheat, especially in grains. The concentrations of heavy metals in wheat roots, stems and leaves reached the peak value during the three-leaf period of spring wheat growth and then gradually decreased. The amount of heavy metal accumulated in spring wheat increased with increasing growth time. The ability to accumulate heavy metals in various tissues of spring wheat was: for Cu, root and leaf stem grains, Zn, root, glutin stem, Pb, root, glutin seed stem, Cd, root stem glum kernel. Increasing the planting density can reduce the accumulation of heavy metals in the grain of spring wheat, especially Pb and Cd, so as to reduce the possible health risks of heavy metals to local residents, and indicate that increasing planting density can be used as a safer production mode for local spring wheat. As the planting density increases, the amount of heavy metal accumulated in the spring wheat in the unit area is reduced, The planting density of plants or crops is one of the key factors that affect the effect of removal. In conclusion, the heavy metal concentration in the soil is heavily polluted by heavy metal, and the heavy metal concentration in the tissues of the spring wheat growing on it is mainly related to soil available nitrogen. The exchangeable state of heavy metal in soil and the concentration of carbonate salt state were positively correlated (P0.01); the accumulation ability of spring wheat to heavy metals had organizational difference, and decreased with the increase of planting density of spring wheat and the extension of growth phase; The accumulation concentration of heavy metals in grain of spring wheat has potential risk to the health of local residents. However, this risk can be reduced by raising the planting density without significantly reducing the yield. In conclusion, the result of this study is of reference to safe production of spring wheat and reduce the health risk of local residents.
【學(xué)位授予單位】：蘭州大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類(lèi)號(hào)】：X53;S512.12
本文編號(hào)：2286281
[Abstract]:Baiyin region is an important heavy metal mining and smelting base in China. The long mining history and excessive industrial and agricultural activities have caused serious pollution to farmland soil system in this area, among which heavy metal pollution is the most serious. Soil heavy metals can accumulate in crops through soil-plant systems, and then enter the human body through the food chain and pose a hazard to human health. Although local soil pollution remediation efforts have been carried out, little success has been achieved. Spring wheat (spring wheat), which is the main food crop, has been widely cultivated locally, but the accumulation of heavy metals in soil under the condition of environmental pollution is still unclear, and the potential risks of long-term consumption to the health of local residents have not been reported in detail. Therefore, the research on the accumulation effect of spring wheat on soil heavy metals and its influencing factors under the condition of environmental pollution is of great significance to the safe production of local crops and to reduce the health risk of local residents as much as possible. In this study, we select the farmland as the research site in Donggugou, Baiyin, and study the concentration of heavy metal copper (Cu), zinc (Zn), lead (Pb), Cd (Cd) and quick-acting nitrogen in soil by measuring the common heavy metal copper (Cu), zinc (Zn), lead (Pb), Cd (Cd). The concentrations of heavy metals in different tissues (roots, stems, leaves, glumes and seeds) of spring wheat (root, stem, leaf, glume and kernel) are determined by collecting and measuring the factors such as phosphorus and pH, The effects of different tissues of spring wheat on the accumulation of heavy metals and their influencing factors are expounded, and the changes of the accumulation of heavy metals in different tissues of spring wheat with the growth period are revealed. To explore the feasibility of reducing the heavy metal concentration and health risk of spring wheat grains by increasing planting density. The results showed that: 1. The pollution of Cu, Zn and Cd in farmland soil along the Daogou sewage ditch of Baiyin is serious, far exceeding the national soil safety standard limit (Cu 100 mg kg-1, Zn 300 mg kg-1, Cd 1 mg kg-1), while the Pb concentration exceeds the safety standard limit value (300 mg kg-1) in the upstream soil. The downstream corresponding concentration is within the safe concentration. The concentration of heavy metals in the local spring wheat tissues of Baiyin was positively correlated with the soil available nitrogen concentration (P0.05). The exchangeable state of heavy metals in soil and the state of carbonate leaching are at a higher level, which promotes the concentration of heavy metals in the tissues of spring wheat, especially in grains. The concentrations of heavy metals in wheat roots, stems and leaves reached the peak value during the three-leaf period of spring wheat growth and then gradually decreased. The amount of heavy metal accumulated in spring wheat increased with increasing growth time. The ability to accumulate heavy metals in various tissues of spring wheat was: for Cu, root and leaf stem grains, Zn, root, glutin stem, Pb, root, glutin seed stem, Cd, root stem glum kernel. Increasing the planting density can reduce the accumulation of heavy metals in the grain of spring wheat, especially Pb and Cd, so as to reduce the possible health risks of heavy metals to local residents, and indicate that increasing planting density can be used as a safer production mode for local spring wheat. As the planting density increases, the amount of heavy metal accumulated in the spring wheat in the unit area is reduced, The planting density of plants or crops is one of the key factors that affect the effect of removal. In conclusion, the heavy metal concentration in the soil is heavily polluted by heavy metal, and the heavy metal concentration in the tissues of the spring wheat growing on it is mainly related to soil available nitrogen. The exchangeable state of heavy metal in soil and the concentration of carbonate salt state were positively correlated (P0.01); the accumulation ability of spring wheat to heavy metals had organizational difference, and decreased with the increase of planting density of spring wheat and the extension of growth phase; The accumulation concentration of heavy metals in grain of spring wheat has potential risk to the health of local residents. However, this risk can be reduced by raising the planting density without significantly reducing the yield. In conclusion, the result of this study is of reference to safe production of spring wheat and reduce the health risk of local residents.
【學(xué)位授予單位】：蘭州大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類(lèi)號(hào)】：X53;S512.12
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，本文編號(hào)：2286281
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