Cu、Zn污染对土壤和植物生境的影响及金属形态的研究

发布时间：2018-02-11 12:28

本文关键词： 土壤重金属污染土壤酶活性植物修复形态分布　出处：《河南师范大学》2016年硕士论文　论文类型：学位论文

【摘要】：首先,本文选取香叶天竺葵和舞草作为修复植物,采用露天盆栽的方法,研究Cu、Zn单一及复合污染对土壤过氧化氢酶、脲酶和蔗糖酶的影响。研究结果表明,在Cu、Zn单一及复合污染条件下,对两组植物的酶活性抑制程度依次为脲酶、蔗糖酶和过氧化氢酶,其中土壤脲酶的酶抑制率最大,敏感程度最强,因此可以使用土壤脲酶作为土壤Cu、Zn污染的监测指标。对比在Cu、Zn单一及复合污染下香叶天竺葵组和舞草组三种酶活性,香叶天竺葵对土壤过氧化氢酶、脲酶和蔗糖酶酶活性的改善作用大于舞草,说明香叶天竺葵对Cu、Zn污染有较强时耐受性和适应性,可以一定程度的减轻Cu、Zn重金属造成的土壤污染,具有修复土壤Cu、Zn污染的潜能。Cu、Zn复合污染条件下,处理浓度为Cu100 mg·kg~(-1)+Zn200 mg·kg~(-1)时,香叶天竺葵和舞草的三种酶均表现较弱程度的拮抗作用,其他组均表现协同作用。同时,Cu、Zn对土壤酶活性的抑制效果为CuZn。其次,本文选取香叶天竺葵作为修复植物,研究不同浓度的Cu、Zn处理时对香叶天竺葵的株高、主根长、生物量、叶绿素和植物各部分重金属含量的影响。研究结果表明,不同浓度的Cu处理下对香叶天竺葵的株高、主根长、生物量和叶绿素含量都有一定的抑制作用;低浓度的Zn(浓度小于200 mg·kg~(-1))对香叶天竺葵的株高、主根长和生物量有一定的促进作用,同时可以促进叶绿素的合成,高浓度的Zn(浓度大于500mg·kg~(-1))对香叶天竺葵的株高、主根长、生物量和叶绿素含量都有一定的抑制作用,此外Cu、Zn对香叶天竺葵茎的影响大于对根的影响,对比两种重金属,Zn对香叶天竺葵的毒害作用小于Cu对香叶天竺葵的毒害作用。香叶天竺葵对Zn的转运系数和富集系数略高于Cu,但是对Cu、Zn两种重金属的转运系数和富集系数均不高,因此香叶天竺葵不能作为Cu、Zn超富集植物。然后,采用盆栽试验研究土壤中外源重金属Cu、Zn随时间变化的形态分布。研究结果表明不同浓度的Cu、Zn进入土壤后主要以残渣态存在于土壤中,其中不同浓度的Cu进入土壤后其形态分布均为残渣态有机结合态铁锰氧化态碳酸盐态交换态,不同浓度的Zn进入土壤后其形态分布均为残渣态铁锰氧化态有机结合态碳酸盐态交换态。随着时间的增加,不同浓度的Cu在土壤中存在形态在20d后达到动态平衡,zn200mg·kg~(-1)和zn1000mg·kg~(-1)处理时土壤中zn各形态在20d后达到动态平衡,但是zn2000mg·kg~(-1)处理时较长时间未达到动态平衡。说明高浓度的zn在土壤中存在形态需要较长时间才能达到动态平衡。
[Abstract]:First of all, the effects of single and complex pollution of Cu Zn on catalase, urease and sucrase in soil were studied by using geranium and chrysanthemum as restoration plants. The inhibition degree of enzyme activity to the two groups of plants was urease, sucrase and catalase under the condition of single and complex pollution of Cu and Zn, among which the enzyme inhibition rate of soil urease was the largest and the sensitivity was the highest. Therefore, soil urease can be used as the monitoring index of soil Cu + Zn pollution. The improvement of urease and sucrase activity was greater than that of Cuccinia chinensis, which indicated that geranium had stronger tolerance and adaptability to Cu Zn pollution, and could alleviate the soil pollution caused by Cu + Zn heavy metals to some extent. Under the condition of compound pollution of Cu100 mg 路kg ~ (-1) Zn200 路kg ~ (-1) Zn200 路kg ~ (-1), the three kinds of enzymes of geranium and Cupulina showed weak antagonism under the condition of potential of remediation of soil Cu ~ (2 +) Zn pollution 路Cu ~ (2 +) Zn compound pollution, and the concentration of treatment was Cu100 mg 路kg ~ (-1) 路kg ~ (-1) Zn200 路kg ~ (-1). Other groups showed synergistic effect, and CuZnZn inhibited soil enzyme activity. Secondly, geranium was selected as repair plant. The plant height, main root length and biomass of geranium were studied under different concentration of Cu-Zn treatment. The effects of different concentrations of Cu on the plant height, main root length, biomass and chlorophyll content of geranium were studied. The low concentration of Zn (< 200mg 路kg ~ (-1)) promoted the plant height, main root length and biomass of geranium, and promoted the synthesis of chlorophyll. High concentration of Zn (> 500 mg 路kg ~ (-1) ~ (-1)) could promote the plant height and root length of geranium. The biomass and chlorophyll content were inhibited to some extent, and the effect of Cu-Zn on the stem of geranium was greater than that on root. The toxicity of Zn to geranium was less than that of Cu to geranium. The transport coefficient and enrichment coefficient of Zn in geranium were higher than that of Cu, but the transport coefficient and enrichment coefficient of Zn were higher than that of Cu. The enrichment coefficient is not high, So geranium leaves can't be used as Cu Zn superrich plants. Then, Pot experiment was used to study the morphological distribution of Cu ~ (2 +) Zn in soil with time. The results showed that different concentrations of Cu ~ (2 +) Zn mainly existed in the soil as residue after entering the soil. When Cu at different concentrations entered the soil, the speciation distribution of Cu was all in the form of residual organic bound ferromanganese oxidized carbonate exchange state. When Zn at different concentrations enters the soil, the speciation distribution of Zn is the organic bound carbonate exchange state of the residual ferromanganese oxidation state, which increases with the increase of time. The forms of Cu in soils with different concentrations reached dynamic equilibrium after 20 days, and reached dynamic equilibrium after 20 days under the conditions of zn1000mg 路kg ~ (-1) and ZN ~ (200 mg 路kg ~ (-1) ~ (-1)). But the zn2000mg 路kg ~ (-1)) treatment did not reach the dynamic equilibrium for a long time, which indicated that it took a long time for the form of zn to exist in the soil to reach the dynamic equilibrium.
【学位授予单位】：河南师范大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X53;X173

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