大豆、龙葵单作和间作对镉、芘污染土壤的修复

发布时间：2019-03-22 12:49

【摘要】：目前,污水灌溉已成为我国最主要的废水利用方式之一,但不合理污水灌溉会导致土壤受到重金属和多环芳烃等污染物的污染,这已成为我国面临的重要环境问题,农田重金属和多环芳烃污染已经成为制约我国粮食生产和经济发展的重要因素。因此,开展重金属、多环芳烃单一及复合污染土壤的修复研究具有十分重要的意义。本文采用室内盆栽试验,选择PAHs中具有代表性的四环化合物芘(Pyrene)作为研究对象,研究了大豆、龙葵单作和间作对不同浓度镉(1、5、25 mg?kg-1)、芘(10、50、250 mg?kg-1)单一及复合污染土壤的修复特征,同时研究了修复过程污染物对大豆籽粒品质的影响。结果表明:(1)对单一镉污染土壤的修复过程中,污染物镉抑制了大豆的生长,而对龙葵的生长影响不明显;间作处理在一定程度上促进了大豆和龙葵的生长;镉在大豆中的分布情况是:地下部分地上部分,而在龙葵中的分布情况是:地上部分地下部分;大豆与龙葵间作在一定程度上促进了龙葵对镉的吸收,间作条件下龙葵地上部分的镉含量分别比单作条件下分别高出17%、19.93%和8.98%;大豆-龙葵间作的镉去除率在10.68%~19.07%之间,各种植模式下镉去除率的情况为:大豆-龙葵间作龙葵单作大豆单作;当土壤中镉浓度为1 mg?kg-1时,单作和间作条件下大豆籽粒中的镉含量便超过了食品中污染物限量标准,但可以考虑通过收获其油分来达到一定的经济效益。因此,大豆-龙葵间作是一种既能有效修复镉污染土壤,又充分利用污染土地资源的修复模式。(2)对单一芘污染土壤的修复的过程中,低浓度的芘(10 mg?kg-1)在一定程度上促进了大豆的生长,而高浓度的芘(250 mg?kg-1)则对大豆的生长有抑制作用;龙葵的生长没有受到芘污染(10~250 mg?kg-1)的影响;间作对大豆、龙葵的生长均有不同程度的促进作用。污染物芘在大豆和龙葵(成熟期)中的分布情况是:地下部分地上部分;间作并未对大豆、龙葵中的芘含量造成显著影响。同一污染水平下,不同种植模式的修复效果为:大豆-龙葵间作大豆单作龙葵单作无植物对照。(3)对镉-芘复合污染土壤的修复过程中,大豆的生长受到了明显的抑制,龙葵的生物量并未受到镉-芘污染的显著影响;间作对大豆的生长有明显的促进作用,而对龙葵的生长促进不明显。镉-芘的相互作用可能增强了污染物对大豆的毒性,而龙葵对镉-芘复合污染有着较好的耐性。与单一镉污染相比,复合污染情况下大豆中镉的含量明显较低,龙葵中的镉含量明显较高,说明多环芳烃芘的存在对大豆、龙葵对镉的吸收特征有着不同的影响;复合污染情况下土壤中镉的去除率明显低于单一污染土壤镉的去除率;复合污染土壤的芘去除率明显低于单一污染土壤芘的去除率。(4)同一污染水平下,镉在大豆各部位中的分布情况是:根部茎叶籽粒;单作间作;本试验中各个处理大豆籽粒中的镉含量均超过了食品中污染物限量标准,不能直接食用,其利用方式尚待进一步研究。
[Abstract]:At present, the sewage irrigation has become one of the most important wastewater utilization methods in China, but the unreasonable sewage irrigation can lead to the pollution of the heavy metal and the polycyclic aromatic hydrocarbon, which has become an important environmental problem in our country. Heavy metal and polycyclic aromatic hydrocarbon pollution have become an important factor in the food production and economic development in China. Therefore, it is of great significance to carry out the research on the single and composite polluted soil of heavy metal, polycyclic aromatic hydrocarbon and compound pollution. In this paper, a representative four-ring compound (Pyrene) in PAHs was selected as the research object, and the repair characteristics of single and composite contaminated soil of soybean and Solanum nigrum were studied. The effect of the pollutant on the grain quality of the soybean was also studied. The results showed that: (1) The growth of the soybean was inhibited by the pollutants, and the growth of the solanum nigrum was not obvious. The distribution of the soybean in the soybean was as follows: (1) The growth of the soybean was inhibited by the pollutant, and the growth of the solanum nigrum was not obvious. The underground part of the underground part, and the distribution of the underground part of the ground part: the underground part of the ground part; the intercropping of the soybean and the nightshade to a certain extent promoted the absorption of the solanum nigrum, and the content of the ground part of the solanum nigrum under the intercropping condition is 17%, 19.93% and 8.98% higher than that under the single-cropping condition respectively; The removal rate of soybean-solanum intercropping was between 10.68% and 19.07%, and the removal rate of soybean-Solanum nigrum was 1 mg 路 kg-1. In that condition of single cropping and intercropping, the content of the oil in the grain of the soybean exceed the limit of the pollutant in the food, but it can be considered to achieve a certain economic benefit by harvesting the oil. Therefore, the soybean-sunflower intercropping is a kind of repair mode which not only can effectively repair the soil polluted by the soil, but also makes full use of the pollution land resources. (2) In the course of the repair of a single contaminated soil, the low concentration of yeast (10 mg? kg-1) promoted the growth of the soybean to a certain extent, while the high concentration of yeast (250 mg? kg-1) had an inhibitory effect on the growth of the soybean; the growth of the Solanum nigrum was not affected by the soil pollution (10-250 mg? kg-1); The intercropping has a different effect on the growth of the soybean and the solanum nigrum. The distribution of the pollutants in the soybean and the solanum nigrum (the mature stage) is the above-ground part of the underground part, and the intercropping does not have a significant effect on the content of the soil in the soybean and the solanum nigrum. Under the same level of pollution, the effects of different planting patterns were as follows: the soybean-Solanum nigrum intercropping soybean was used as a non-plant control. (3) The growth of the soybean was obviously inhibited in the process of the restoration of the soil from the compound contaminated soil, and the biomass of the solanum nigrum was not affected by the pollution of the soil. The intercropping of the soybean had a significant effect on the growth of the soybean, and the growth of the solanum nigrum was not obvious. The interaction of HCO3-1 may enhance the toxicity of the pollutants to the soybean, while the Solanum nigrum has a good resistance to the compound pollution of the soybean. Compared with the single-chain pollution, the content of the soybean in the soybean is obviously lower, and the content of the sulfur in the solanum nigrum is obviously higher, which indicates that the existence of the polycyclic aromatic hydrocarbon is different to the absorption characteristics of the soybean and the solanum nigrum to the soybean. The removal rate of the soil in the soil is lower than that of the single-polluted soil, and the removal rate of the soil is lower than that of the single-polluted soil. (4) In the same level of pollution, the distribution of the root of the soybean in the parts of the soybean is as follows: the root and leaf grains; the single cropping and the intercropping; in the test, the content of the selenium in each of the treated soybean grains exceeds the limit standard of the pollutant in the food, can not be eaten directly, and the utilization mode of the soybean is to be further researched.
【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X53;X173

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