施用木炭和硫酸亚铁对铅锌矿区农田水稻吸收重金属影响

发布时间：2018-03-25 09:59

本文选题：铅锌矿区　切入点：重金属污染　出处：《安徽农业大学》2017年硕士论文

【摘要】：采矿活动是土壤重金属污染的一个重要污染源头,在采矿过程中产生的污染物,通过各种途径进入周边土壤,对周边农田土壤产生不同程度的重金属污染。对周边污染程度较低的农田,我们可以通过改变耕作制度的方法,减少农作物对重金属的吸收,使低污染农田生产出符合食品标准的农作物。本文选择安徽某铅锌矿周边农田为研究对象,采集测定铅锌矿周边农田以及农田生产出的农作物,对周边农田及其生产的农作物进行调查,以矿区污染土壤为供试土壤,研究多种品种水稻对矿区污染土壤吸收累积重金属特性,并且通过室内和田间添加改良剂试验,研究了施加木炭和硫酸亚铁对水稻重金属积累的影响,深入研究了硫酸亚铁诱导水稻根表铁膜产生及其对水稻吸收铜锌的影响。为该地区的水稻安全生产提供理论和实践帮助。主要研究结果如下:(1)通过对安徽某铅锌矿周边农田及农作物采样测定,结果显示铅锌矿周边农田Zn含量范围为162.49-488.03 mg/kg,变异系数为26.7%;As的含量范围为39.95-100.73mg/kg,变异系数为23.96%;Cd的含量范围为0.35-1.88 mg/kg,变异系数为37.84%。Zn、As和Cd的平均含量均超过了国家土壤环境质量二级标准。周边农田的水稻糙米和小麦籽粒As平均含量为0.48 mg/kg和0.49 mg/kg,均超过了国家食品安全标准。(2)通过盆栽实验的方式,以矿区周边农田污染土壤为试供土壤,研究不同品种水稻重金属积累差异。结果显示,水稻糙米Cd含量为0.03-0.13 mg/kg,最高值和最低值相差4倍;Zn含量为22.41-39.59 mg/kg,最高值和最低值相差不到1倍;Pb含量为0.05-0.17 mg/kg,最高值和最低值相差3倍;As含量为0.25-0.41 mg/kg,最高值和最低值相差不到1倍。(3)通过水培条件下添加硫酸亚铁诱导水稻根表铁膜的形成,利用DCB(连二亚硫酸钠-碳酸氢钠-柠檬酸钠)溶液、扫描电镜、能谱仪和X射线衍射对硫酸亚铁诱导产生的根表铁膜进行表征,研究根表铁膜对水稻吸收铜锌的影响,结果显示通过添加硫酸亚铁可以诱导大量的根表铁膜在水稻根系表面产生,通过DCB(连二亚硫酸钠-碳酸氢钠-柠檬酸钠)溶液和扫描电镜等手段可以发现,未处理的水稻根表DCB提取液Fe含量为731 mg/kg,80 mg/kgFe2+处理下水稻根表DCB提取液Fe含量为53562mg/kg。培养根表铁膜的水稻相比未处理水稻,根表铁膜Cu含量最高增加了73.16%,Zn含量最高增加了112.10%;根部Cu含量最高降低了31.15%,Zn含量最高降低了13.02%;茎叶Cu含量最高降低了19.50%,Zn含量最高降低了25.56%。(4)通过盆栽和田间试验研究矿区污染土壤添加木炭和硫酸亚铁对水稻吸收砷锌镉的影响,对不同处理组下土壤pH,土壤重金属形态、水稻产量和水稻各部分重金属含量测定。实验结果表明,施加木炭和硫酸亚铁可以促进水稻的生长发育,增加水稻产量和生物量,发现添加木炭可以提高土壤的pH,添加木炭可以显著降低土壤中Cd和Zn的弱酸提取态,其最大降低幅度达36.17%和23.61%。添加木炭处理的水稻糙米Cd和Zn相较CK下降了67.91%和27.19%;叶面喷施硫酸亚铁的水稻糙米Cd和As相较CK下降了54.84%和33.33%;土壤添加硫酸亚铁的水稻糙米Cd和As相较CK下降了22.58%和66.67%。
[Abstract]:The mining activity is an important source of pollution of soil heavy metal pollution, pollutants produced during the mining process, into the surrounding soil through various channels to produce different degrees of heavy metal pollution on the surrounding soil. The pollution surrounding the low degree of farmland, we can through the change of farming system, reduce the uptake of heavy metals by crops. The low pollution of agricultural production to meet the standards of food crops. This paper chooses a lead-zinc mine in Anhui surrounding farmland as the research object, collecting and determining farmland around the lead-zinc mine and farmland produce crops, crop production and the surrounding farmland were investigated to mine contaminated soil as tested soil, heavy metal accumulation on several rice varieties the characteristics of mine contaminated soil, and through indoor and field test of adding modifier, charcoal and sulfur on ferrous acid Effect of the accumulation of heavy metals in rice, in-depth study of ferrous sulfate induced iron film produced by rice roots and the absorption effect of copper and zinc on rice. To provide theory and Practice for the area of safe production of rice. The main results are as follows: (1) by means of a lead-zinc mine in Anhui surrounding farmland and crop sampling and determination, results showed that zinc mine farmland around the Zn content is in the range of 162.49-488.03 mg/kg, the coefficient of variation was 26.7%; the range of As content was 39.95-100.73mg/kg, the coefficient of variation was 23.96%; in the range of Cd to 0.35-1.88 mg/kg, the coefficient of variation was 37.84%.Zn, the average content of As and Cd were more than two national standards of soil environment quality. The average content of rice and wheat As surrounding farmland is 0.48 mg/kg and 0.49 mg/kg, exceeded the national food safety standards. (2) by pot experiment, the mining area surrounding farmland soil Test for soil, study on different varieties of rice heavy metal accumulation difference. The results showed that Cd content in brown rice was 0.03-0.13 mg/kg, the maximum and minimum value is 4 times; the content of Zn is 22.41-39.59 mg/kg, the maximum and minimum value is less than 1 times; the content of Pb is 0.05-0.17 mg/kg, the highest and the lowest value is 3 times the content of As is 0.25-0.41; mg/kg maximum and minimum value is less than 1 times. (3) through the formation of hydroponics adding ferrous sulfate induced rice root iron film, using DCB (with two of sodium bicarbonate and sodium citrate solution), scanning electron microscopy, iron plaque spectrometer and X the X-ray diffraction of ferrous sulfate induced characterized iron membrane absorption effect of copper and zinc on the surface of rice root, the results showed that by adding ferrous sulfate can induce root iron film produced in rice root surface by DCB (with two of sodium hydrogen carbonate Sodium citrate solution) and scanning electron microscopy can be found in the untreated rice root extract DCB content of Fe was 731 mg/kg, 80 mg/kgFe2+ DCB water extract Fe content for 53562mg/kg. culture of iron plaque on root surface of rice compared to untreated rice table rice root, root Cu content of the highest increase in iron film 73.16%, the highest content of Zn increased by 112.10%; the highest Cu content in roots decreased by 31.15%, the highest content of Zn was reduced by 13.02%; the content of Cu in stem and leaf is reduced up to 19.50%, the highest content of Zn was reduced by 25.56%. (4) by pot and field experiment of mine contaminated soil with charcoal and ferrous sulfate of zinc and cadmium on the absorption effect of arsenic rice, soil pH in different treatment groups, the forms of heavy metals in soil and rice yield determination, each part of the content of heavy metals. The experimental results show that the application of charcoal and ferrous sulfate can promote rice growth, increased rice The yield and biomass, found that adding charcoal can improve soil pH, adding charcoal can significantly reduce Cd and Zn in soil, acid extractable state, the largest decrease up to 36.17% 23.61%. and add wood charcoal treated rice Cd and Zn in CK decreased by 67.91% and 27.19%; foliar application of ferrous sulfate in brown rice Cd and As compared with CK decreased by 54.84% and 33.33%; soil adding ferrous sulfate rice Cd and As compared with CK decreased by 22.58% and 66.67%.

【学位授予单位】：安徽农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X53;X503.231

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