石灰、硅酸钠和羟基磷灰石对烟草吸收镉、铅的影响

发布时间：2018-06-26 01:01

本文选题：重金属 + 烟草　；参考：《福建农林大学》2017年硕士论文

【摘要】：为了探讨施用不同钝化剂对烟草吸收富集镉、铅的效果,采用盆栽试验研究了消石灰、硅酸钠和羟基磷灰石对镉、铅复合污染土壤上的烟草镉、铅吸收富集的影响。结果表明:(1)土壤pH值均随三种钝化剂用量的增大而升高,土壤有效镉、铅(DTPA-提取)含量则随之降低。土壤有效镉降幅最大的处理是 32g·kg-1 羟基磷灰石(52.4%)6g·kg-1 石灰(37%)2.5g·kg-1硅酸钠(14.1%)。土壤有效铅降幅最大的处理是32 g·kg-1羟基磷灰石(58.5%)16 g·kg-1 石灰(35.7%)12.5 g·kg-1 硅酸钠(18.1%)。(2)三种钝化剂都促进了烟草的生长,在增加烟草叶片数和增大叶面积方面的效果大小为:羟基磷灰石石灰硅酸钠;在提升烟株生长高度方面的效果大小为:石灰羟基磷灰石硅酸钠;对烟株不同部位干重增加的效果依次为:石灰羟基磷灰石硅酸钠,对不同部位生物量的增加效果依次为:茎叶根。(3)除了施用2.5 g·kg-1硅酸钠处理外,三种钝化剂均抑制了烟草各部位对Cd的吸收富集,抑制程度随钝化剂用量的增加呈增大趋势。在镉和铅严重污染的土壤上、高施用量处理(8～16 g·kg-1石灰或7.5～12.5 g·kg-1硅酸钠或8～32 g·kg-1羟基磷灰石)条件下,3种钝化剂对烟叶镉含量的降低效果依次为:石灰羟基磷灰石硅酸钠。(4)低施用量(2、4g·kg-1)石灰或低施用量(2、4g·kg-1)羟基磷灰石略微提高了烟叶中的铅含量,而高施用量(12、16 g·kg-1)的石灰或高施用量(16、32 g·kg-1)的羟基磷灰石则表现出了对烟叶富集铅的显著抑制作用,施用16 g·kg-1石灰处理和施用32 g·kg-1羟基磷灰石处理的烟叶铅含量均降至铅限量标准(15mg·kg-1)以下。施用硅酸钠没有对烟叶中铅含量产生影响。(5)镉从根系向茎部的转移是镉在地上部累积的限制环节。石灰和羟基磷灰石对镉从根到茎之间的转移无显著影响,而硅酸钠则降低了镉从根到茎之间的转移。石灰、高施用量(7.5、10、12.5g·kg-1)硅酸钠和羟基磷灰石可以有效抑制根部从土壤中吸收铅和铅从根部向地上部的转移,但施用三种钝化剂都促进了铅从烟株茎向烟叶的转移。(6)施用石灰和羟基磷灰石对土壤有效镉和有效铅的降低是引起烟草根部镉和铅含量降低的主要原因。施用石灰和羟基磷灰石对土壤有效镉的降低是抑制烟叶富集镉的重要原因,而硅酸钠的效果较复杂。施用石灰和羟基磷灰石抑制烟叶富集铅的植物体内的机制主要是抑制烟株根系对铅的吸收。
[Abstract]:In order to study the effect of different passivating agents on the absorption and enrichment of cadmium and lead in tobacco, pot experiments were conducted to study the effects of lime, sodium silicate and hydroxyapatite on the absorption and enrichment of cadmium and lead in tobacco on the soil polluted by cadmium and lead. The results showed that: (1) the pH value of soil increased with the increase of the amount of three passivating agents, and the contents of available cadmium and lead (DTPA-extract) decreased with the increase of the amount of three passivators. The treatment with the largest decrease in available cadmium was 32g kg-1 hydroxyapatite (52.4%), 6g kg-1 lime (37%) and 2.5g kg-1 sodium silicate (14.1%). The most significant reduction of available lead in soil was that 32 g kg-1 hydroxyapatite (58.5%), 16 g kg-1 lime (35.7%) and 12.5 g kg-1 sodium silicate (18.1%). (2) promoted the growth of tobacco. The effects of increasing tobacco leaf number and leaf area were as follows: sodium hydroxyapatite lime silicate and lime hydroxyapatite sodium silicate in raising the height of tobacco plant. The effect of increasing dry weight of different parts of tobacco plant was: lime hydroxyapatite sodium silicate, biomass of different parts in turn: stem and leaf root. (3) except for the treatment of 2.5 g sodium silicate, The absorption and enrichment of CD in different parts of tobacco were inhibited by the three passivators, and the inhibition degree increased with the increase of the amount of passivator. In the soil heavily polluted by cadmium and lead, The decreasing effects of three passivators on cadmium content in tobacco leaves under high application conditions (8g kg-1 lime or 7.5 g kg-1 sodium silicate or 832 g kg-1 hydroxyapatite) were as follows: lime hydroxyapatite sodium silicate. (4) low dosage (2g kg-1). Lime or low dosage (2g kg-1) hydroxyapatite slightly increased the lead content in tobacco leaves. The lime with high application rate (12g / kg-1) or hydroxyapatite with high application rate (163g / kg-1) showed significant inhibitory effect on Pb enrichment in tobacco leaves. The lead content of tobacco leaves treated with 16 g kg-1 lime and 32 g kg-1 hydroxyapatite decreased below the lead limit standard (15mg kg-1). The application of sodium silicate had no effect on the content of lead in tobacco leaves. (5) the transfer of cadmium from root to stem was the limitation of cadmium accumulation in shoot. Lime and hydroxyapatite had no significant effect on the transfer of cadmium from root to stem, while sodium silicate decreased the transfer of cadmium from root to stem. Lime, sodium silicate and hydroxyapatite at high application rate (7.5 ~ 10g kg-1) could effectively inhibit the transfer of lead and lead from the root to the ground. However, the application of three passivating agents promoted the transfer of lead from stem to leaf. (6) the decrease of available cadmium and available lead in soil by applying lime and hydroxyapatite was the main reason for the decrease of cadmium and lead content in tobacco roots. The decrease of available cadmium in soil by applying lime and hydroxyapatite is an important reason to inhibit the accumulation of cadmium in tobacco leaves, but the effect of sodium silicate is more complex. The mechanism of applying lime and hydroxyapatite to inhibit Pb accumulation in tobacco leaves is to inhibit the absorption of Pb by tobacco roots.
【学位授予单位】：福建农林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X53

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