芝麻与蓖麻对土壤重金属的吸收积累特性、修复潜力及提油后粕饼的脱毒研究
发布时间：2018-10-15 16:17
【摘要】：在湖南郴州尾矿区污染严重的废弃农田,选取三种油料作物油菜、芝麻和蓖麻为研究对象,对比三种油料作物对土壤中重金属(Cu、Zn、Pb、Cd、As和Hg)的吸收积累能力,计算油菜-芝麻轮作模式对重金属污染土壤的修复潜力；研究五种有机溶剂(正己烷、石油醚、丙酮、异丙醇和氯仿)对蓖麻籽的提油效果,分析确定一种最优的提油溶剂；分析三种有机盐溶液(柠檬酸钾、酒石酸钾、EDTA铵盐)对提油后蓖麻粕中重金属的去除效果。研究结果如下：(1)各重金属在作物各组织部位中的积累分别存在明显的差异。其中,Cu、Zn、Cd和Hg主要积累在油菜的叶中,而Pb和As主要积累在地下部分的根中。芝麻中Zn、 Pb和Cd主要集中在根中,其次是叶；而Cu、As和Hg则刚好相反,主要积累在叶中,其次是根。几种重金属和As在蓖麻中的积累分布都表现为地下部分根中的含量远高于地上部分,其次是叶。油菜除了对地上部分叶对Hg的富集能力最强,对其他重金属的富集能力都较弱；芝麻和蓖麻对Cu和Cd都表现出很好的富集能力,尤其是芝麻地上部分叶和地下部分根对Cu和Cd的富集系数都大于1。(2)本研究利用油菜-芝麻轮作模式,虽然两种油料作物各部分中重金属的浓度远不如超富集植物那么高,但是其总的干物质量能够达到800-1000kg/亩,远远大于超富集植物的生物量,从而使得它们能够有效的提取土壤中的重金属。油菜和芝麻对各种重金属的富集能力又不一样,这样两者轮作可以起到一个互补的作用,使得这样的轮作模式非常适用于重金属复合污染的农田土壤。(3)五种不同的有机溶剂所提取出的蓖麻油,提油率最高的是氯仿,高达33.74%,其次是丙酮31.05%。并且从安全角度来考虑,选择氯仿对蓖麻油进行提取是最好的选择。由于在蓖麻油中未检测出Cd和Hg,且能检测出的重金属中,重金属的含量远远小于蓖麻果皮中的浓度,因此认为大量的重金属任然存在于蓖麻粕中。(4)对比三种萃取剂对蓖麻粕的脱毒,在只浸提一次的情况下,整体脱毒效果最好的是EDTA铵盐,且随着萃取剂浓度的提高,脱毒效果越好。在30 mmol/L时,EDTA铵盐对Zn的去除率达到了77.480%,同时Cu的去除率达到了76.212%,Pb的去除率达到了58.581%,Cd的去除率达到了60.217%,相对于柠檬酸钾和酒石酸钾来说,其脱毒效果是比较好的。但是酒石酸钾对Cd的脱毒效果是三种萃取剂中最高的,只去除Cd时,酒石酸钾是很好的选择。柠檬酸钾在各个方面相对于这两个萃取剂都没有特别明显的优势。(5)在连续三次浸取30mmol/L的萃取剂的情况下,对蓖麻粕的综合脱毒效果最好的是EDTA铵盐,EDTA铵盐对Zn的去除率达到了97.720%,同时Cu的去除率达到了90.206%,Pb的去除率达到了80.553%,Cd的去除率达到了85.478%,As的去除率达到了63.990%,相较于柠檬酸钾和酒石酸钾,综合脱毒效果最好。其次是酒石酸钾对Cd的脱毒效果达到了最高的94.282%,如果只是单独的对Cd的进行脱毒,可以优先考虑酒石酸钾。
[Abstract]:In order to study the absorption and accumulation of heavy metals (Cu, Zn, Pb, Cd, As and Hg) in soil, three types of oilseed rape, sesame and rape were selected as the research object. To evaluate the effect of five organic solvents (n-hexane, petroleum ether, acetone, isopropanol and chloroform) on the recovery potential of heavy metal contaminated soil, and to determine an optimal extraction solvent. The effect of three kinds of organic salt solution (potassium citrate, potassium tartrate, EDTA disodium hydrogen phosphate) on the removal of heavy metals in rapeseed meal after extraction was analyzed. The results are as follows: (1) The accumulation of heavy metals in each tissue site of crops has obvious difference. Among them, Cu, Zn, Cd and Hg are mainly accumulated in the leaves of rape, while Pb and As are mainly accumulated in the roots of the underground part. Zn, Pb and Cd in sesame are mainly concentrated in roots, followed by leaves; while Cu, As and Hg are just opposite, mainly in leaves, followed by roots. The accumulation and distribution of several heavy metals and As in the soil is much higher than that in the upper part of the ground, followed by the leaves. In addition to the strongest enrichment ability of the leaves on the ground, the enrichment ability of the other heavy metals is weak; both the sesame and the Cd show good enrichment ability for Cu and Cd, especially the enrichment coefficient of Cu and Cd is greater than 1 on the upper part of the sesame and the root of the underground part. (2) Although the concentration of heavy metals in each part of the two oil crops is not as high as that of super-enriched plants, the total dry yield can reach 800-1000kg/ mu, which is much larger than that of super-enriched plants. so that they can effectively extract heavy metals from the soil. The enrichment ability of rape and sesame to various heavy metals is different, so that the rotation of both can play a complementary role, so that the rotation mode is very suitable for farmland soil with heavy metal composite pollution. (3) Five different organic solvents extracted from the organic solvent, the highest oil extraction rate was chloroform, high to 33. 74%, followed by acetone 31. 05%. and it is the best choice to select chloroform for extraction from a safety standpoint. Since Cd and Hg are not detected in the cottonseed oil, and the content of heavy metals in the detected heavy metals is much smaller than the concentration in the citrus peel, a large amount of heavy metals are considered to be present in the sunflower meal. (4) Compared with the three extraction agents, the detoxication of three kinds of extraction agents is the best in the case of leaching only once, and the better the detoxification effect with the increase of the concentration of the extractant. When 30mmol/ L, the removal rate of Zn was 77. 480%, and the removal rate of Cu reached 76. 212%, the removal rate of Pb reached 58. 581%, the removal rate of Cd reached 60. 217%, and the detoxification effect was better for potassium citrate and potassium tartrate. However, the detoxification effect of potassium tartrate on Cd is the highest in three extractants, and the potassium tartrate is a good choice when Cd is removed. Potassium citrate has no particular advantage over all aspects with respect to both extractants. (5) In the case of three consecutive leaching of 30mmol/ L extractant, the removal rate of Zn was 97.0%, and the removal rate of Cu reached 90. 206%, and the removal rate of Pb was up to 85.3%, and the removal rate of Cd reached 85. 478%. As the removal rate of As was 63. 990%, the phase was better than potassium citrate and potassium tartrate. Second, the detoxification effect of potassium tartrate on Cd reached the highest 94. 282%, and if it was only a separate detoxification of Cd, potassium tartrate was preferentially taken into account.
【学位授予单位】：湖南农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X53
本文编号：2273085
[Abstract]:In order to study the absorption and accumulation of heavy metals (Cu, Zn, Pb, Cd, As and Hg) in soil, three types of oilseed rape, sesame and rape were selected as the research object. To evaluate the effect of five organic solvents (n-hexane, petroleum ether, acetone, isopropanol and chloroform) on the recovery potential of heavy metal contaminated soil, and to determine an optimal extraction solvent. The effect of three kinds of organic salt solution (potassium citrate, potassium tartrate, EDTA disodium hydrogen phosphate) on the removal of heavy metals in rapeseed meal after extraction was analyzed. The results are as follows: (1) The accumulation of heavy metals in each tissue site of crops has obvious difference. Among them, Cu, Zn, Cd and Hg are mainly accumulated in the leaves of rape, while Pb and As are mainly accumulated in the roots of the underground part. Zn, Pb and Cd in sesame are mainly concentrated in roots, followed by leaves; while Cu, As and Hg are just opposite, mainly in leaves, followed by roots. The accumulation and distribution of several heavy metals and As in the soil is much higher than that in the upper part of the ground, followed by the leaves. In addition to the strongest enrichment ability of the leaves on the ground, the enrichment ability of the other heavy metals is weak; both the sesame and the Cd show good enrichment ability for Cu and Cd, especially the enrichment coefficient of Cu and Cd is greater than 1 on the upper part of the sesame and the root of the underground part. (2) Although the concentration of heavy metals in each part of the two oil crops is not as high as that of super-enriched plants, the total dry yield can reach 800-1000kg/ mu, which is much larger than that of super-enriched plants. so that they can effectively extract heavy metals from the soil. The enrichment ability of rape and sesame to various heavy metals is different, so that the rotation of both can play a complementary role, so that the rotation mode is very suitable for farmland soil with heavy metal composite pollution. (3) Five different organic solvents extracted from the organic solvent, the highest oil extraction rate was chloroform, high to 33. 74%, followed by acetone 31. 05%. and it is the best choice to select chloroform for extraction from a safety standpoint. Since Cd and Hg are not detected in the cottonseed oil, and the content of heavy metals in the detected heavy metals is much smaller than the concentration in the citrus peel, a large amount of heavy metals are considered to be present in the sunflower meal. (4) Compared with the three extraction agents, the detoxication of three kinds of extraction agents is the best in the case of leaching only once, and the better the detoxification effect with the increase of the concentration of the extractant. When 30mmol/ L, the removal rate of Zn was 77. 480%, and the removal rate of Cu reached 76. 212%, the removal rate of Pb reached 58. 581%, the removal rate of Cd reached 60. 217%, and the detoxification effect was better for potassium citrate and potassium tartrate. However, the detoxification effect of potassium tartrate on Cd is the highest in three extractants, and the potassium tartrate is a good choice when Cd is removed. Potassium citrate has no particular advantage over all aspects with respect to both extractants. (5) In the case of three consecutive leaching of 30mmol/ L extractant, the removal rate of Zn was 97.0%, and the removal rate of Cu reached 90. 206%, and the removal rate of Pb was up to 85.3%, and the removal rate of Cd reached 85. 478%. As the removal rate of As was 63. 990%, the phase was better than potassium citrate and potassium tartrate. Second, the detoxification effect of potassium tartrate on Cd reached the highest 94. 282%, and if it was only a separate detoxification of Cd, potassium tartrate was preferentially taken into account.
【学位授予单位】：湖南农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X53
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1 彭歆琼;芝麻与蓖麻对土壤重金属的吸收积累特性、修复潜力及提油后粕饼的脱毒研究[D];湖南农业大学;2015年
，本文编号：2273085
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