石灰类钝化剂对土壤镉修复机理及油麦菜吸收镉的影响

发布时间：2017-12-28 08:21

本文关键词：石灰类钝化剂对土壤镉修复机理及油麦菜吸收镉的影响　出处：《沈阳农业大学》2017年硕士论文　论文类型：学位论文

【摘要】：针对目前我国土壤环境状况质量下降,土壤重金属污染日益严重的现状,开展对镉污染农田修复与治理对保证农产品质量安全具有重要现实意义。本研究通过盆栽实验,研究了施用方解石粉、赤泥、碳酸钙粉等石灰物质对污染土壤镉形态变化和降低油麦菜吸收镉的影响。获得的主要研究结果如下:(1)所有处理较对照pH值均有显著上升,其中添加赤泥处理对提高土壤pH值作用最大,使其上升了 0.82～1.50个单位;其次是方解石,土壤pH值上升了 0.84～1.23;添加碳酸钙处理与方解石效果相近,使土壤pH值上升0.89～1.01个单位。(2)三种钝化剂均能有效降低土壤有效态镉含量。施用赤泥处理使土壤有效态镉含量降低了 2.7%～33.3%,碳酸钙处理使土壤有效态镉含量降低了 6.7%～27.9%,方解石处理对土壤有效态镉含量降低了 14.3%～33.2%。将三种钝化剂处理的pH与有效态做相关分析表明,赤泥处理的pH值与有效态呈极显著负相关,碳酸钙的处理发现二者呈极显著负相关关系,方解石处理的pH值与有效态无显著相关关系。(3)对土壤中镉赋存形态影响研究发现,施用三种钝化剂分别使土壤中镉形态发生了一系列变化。其中,土壤可交换态镉含量和铁锰氧化物结合态镉含量有一定程度的降低,且呈现随施用剂量增加降幅增大的趋势。三种钝化剂对土壤可交换态镉的转化效率影响大小顺序为:方解石粉赤泥碳酸钙粉;施用三种钝化剂都使土壤碳酸盐结合态镉含量和残渣态镉含量有了很大的升高;对土壤有机结合态镉的影响较小,且规律性不强。(4)施用供试的三种钝化剂后,均能显著降低油麦菜对土壤镉的吸收,植株地上和地下部分的镉含量降幅分别为12.57%～48.01%和12.63%～58.72%。其中,三种钝化剂对油麦菜地上茎叶部分镉含量降低幅度顺序为:方解石赤泥碳酸钙,对地下部分镉含量影响为:方解石碳酸钙赤泥;另外,同一种钝化剂,剂量越大,钝化效果越好,5%剂量的效果与其他剂量有显著差异;施用低剂量时,同计量条件下,赤泥和方解石粉的钝化效果明显好于碳酸钙的,而在高剂量下,三者则无显著差异。(5)土壤镉污染能够影响油麦菜的正常生长,在本供试土壤镉污染条件下,油麦菜的鲜重和株高比清洁土壤处理(CK0)的分别降低了 44.18%和34.46%。适量施加钝化剂可以减轻镉污染对油麦菜生长的影响。添加赤泥处理的表现为随施用剂量的增加使油麦菜鲜重和株高先升后降,1%剂量为最大生物量,3%和5%剂量的处理使鲜重减产;碳酸钙处理的油麦菜生物量随剂量增加持续上升,方解石处理的对油麦菜生物量影响的趋势是随方解石粉剂量增加先升后略微下降达到稳定,3%剂量的方解石粉处理使生物量达到最大值,也是所有处理中生物量最大的处理。
[Abstract]:Aiming at the deterioration of soil environmental quality and the increasingly serious pollution of heavy metals in soil in China, it is of great practical significance to carry out remediation and remediation of Cadmium Contaminated Farmland to ensure the quality and safety of agricultural products. This study through the pot experiment, the effects of red mud, calcite powder, calcium carbonate powder lime material cadmium fractions in contaminated soil changes and reduce the influence of cadmium absorption of lettuce. The main results are as follows: (1) all treatments compared with the control values of pH have increased significantly, the addition of red mud treatment had the biggest effect on improving soil pH value, which rose 0.82 to 1.50 units; followed by calcite, soil pH value increased by 0.84 ~ 1.23; adding calcium carbonate and calcite have similar effects. The soil pH value increased from 0.89 to 1.01 units. (2) all three kinds of passivating agents can effectively reduce the content of available cadmium in soil. The application of red mud reduced soil available cadmium content by 2.7% to 33.3%. Calcium carbonate treatment reduced soil available cadmium content by 6.7% to 27.9%. Calcite treatment reduced soil available cadmium content by 14.3% to 33.2%. Correlation analysis between pH and available state treated with three passivating agents showed that pH value of red mud treatment had a very significant negative correlation with available state. Calcium carbonate treatment showed a significant negative correlation between the two, and calcite treated pH value had no significant correlation with the available state. (3) the study on the influence of cadmium in soil found that the application of three kinds of passivating agents, respectively, made a series of changes in the form of cadmium in the soil. The content of exchangeable cadmium in soil and the cadmium content of ferromanganese oxide bound state decreased to a certain extent, and showed a tendency to increase with the increase of application dose. Three kinds of Passivator on conversion efficiency of soil exchangeable cadmium affects the order of the red mud calcite powder calcium carbonate powder; application of three kinds of passivating agent made the soil carbonate bound cadmium content and residual cadmium content has been greatly increased; the effect of soil organic bound cadmium is small, and no regularity strong. (4) the application of three kinds of test passivation agent, can significantly reduce the absorption of cadmium in soil by cadmium content in lettuce, plant aboveground and underground parts were 12.57% ~ 48.01% and 12.63% ~ 58.72%. Among them, three kinds of Passivator on lettuce stem and leaf cadmium content reduced order: red mud calcite calcium carbonate, effects on the underground part of the cadmium content: calcite calcium carbonate mud; in addition, the same kind of passivation, the higher the dose, the better passivation effect, there was significant difference between the 5% dose effect with other dosage; the application of low dose, with the measuring conditions, the passivation effect of red mud and calcite powder was better than calcium carbonate, while at high doses, there is no significant difference between the three. (5) soil cadmium pollution can affect the normal growth of lettuce, the test conditions of cadmium contaminated soil, lettuce fresh weight and plant height of clean soil treatment (CK0) were reduced by 44.18% and 34.46%. The amount of amendments can reduce the cadmium pollution effects on lettuce growth. Add the red mud treatment was increased with the application dosage of the lettuce fresh weight and plant height after the 1% dose of Mr. fall, the maximum biomass, 3% and 5% doses of the fresh cut lettuce; the amount of biological calcium carbonate treatment continued to increase along with the increase of the dose, the effect of treatment on calcite dish biomass oil wheat trend is first increased and then decreased slightly with increasing stable calcite powder, calcite powder processing to 3% doses of the maximum of biomass and biomass in all treatments is the biggest deal.
【学位授予单位】：沈阳农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X53

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