草本植物根际多环芳烃降解对氮沉降增加的短期响应
发布时间：2018-07-13 10:32
【摘要】：植物根际降解土壤中污染物是植物修复技术中非常重要的一部分,是土壤学、植物学、毒理生态学及环境科学等学科重要研究前沿之一。尤其是在氮沉降日益增加的大环境下,少量的氮沉降会在短期内提高生态系统生产力,积累更多生物量,而过量的氮沉降会导致植物营养过剩、土壤酸化,影响生态系统稳定性等危害。那么,在干旱区,氮沉降的增加是否会影响石化工厂周边草场植被对多环芳烃(Polycyclic Aromatic Hydrocarbons,PAHs)的降解能力,若有降解,那么其降解机制和随氮沉降增加所发生的变化又是什么,都还有待研究。这对土壤污染修复和生态环境管理与建设都具有一定的参考价值。研究通过在新疆独山子区石化工厂周边模拟氮沉降增加试验,经分析当地博乐蒿、旱麦草、四齿芥三种优势草本植物,筛选出根际土壤环境状况、酶活性以及微生物功能多样性较好的博乐蒿为主要研究对象,设置CK(无任何处理)、N0(0 kg N/hm~2·a)、N1(10 kg N/hm~2·a)、N2(30 kg N/hm~2·a)、N3(90 kg N/hm~2·a)共五个处理,每隔一个月进行一次氮添加,于2016年5月25日始至2016年8月19日终,对施氮前后的土壤样品进行分析和比较。得到如下结果:(1)不同植物根际与非根际土微生物代谢强度不同,博乐蒿根际土具有较好的微生物代谢活性(AWCD);各植物根际土壤微生物AWCD、优势度指数(Simpson)、丰富度指数(Shannon)、均匀度指数(McIntosh)均大于非根际土;且根际土壤微生物对糖类、脂类、酸类和胺类碳源物质比较敏感,非根际土壤微生物敏感于酸类、氨基酸类以及糖类碳源物质,根际土壤微生物的碳源利用宽度更大。研究表明,植被的存在能够促进土壤酶活性、提高土壤微生物代谢活性和功能多样性,土壤状况越好,越有利于适应环境变化。三种植物根际与非根际土壤的脱氢酶、过氧化氢酶和脲酶活性的分析中,博乐蒿根际与非根际土壤的三种酶活性均最高,且三种植物根际土壤酶活性均大于非根际土。与土壤化学性质的相关分析发现,影响土壤微生物功能多样性的主要因子有pH、土壤有机质(SOM)、速效磷(AP)和硝态氮(NO_3~--N);根际土壤中PAHs与土壤EC、土壤含水量和pH具有正效应;非根际土壤中,铵态氮(NH_4~+-N)和AP的增加能够加强PAHs的去除效果。(2)氮沉降增加在短期内(3个月)增强了博乐蒿根际土壤中脱氢酶、过氧化氢酶与脲酶活性;提高了根际土壤中的AWCD、Shannon和McIntosh,同时避免了根际微生物绝对优势种的出现;能够较好的减少土壤中2环(萘)与4环(屈)多环芳烃的含量,在总多环芳烃的去除效果中也存在一定的正效应。短期不同水平氮添加处理中,30 kg N/hm~2·a的添加量对博乐蒿根际土壤中酶活性与微生物功能多样性都具有较好的促进作用,尤其是在PAHs的去除中,2~5环多环芳烃(分别为萘、菲、屈、苯并[a]芘)以及总多环芳烃的含量在此氮水平下均有显著减少(P0.05)。博乐蒿根际土壤微生物在30 kg N/hm~2·a的氮添加处理中对六种碳源物质的利用强度均最大,CK、N1、N2和N3处理主要利用的碳源物质为脂类,对酸类物质利用强度最小;无氮添加和无水处理组的根际土壤微生物对碳源的利用能力较弱,表明氮沉降的增加能够明显改变土壤微生物功能多样性;基于主成分分析,酸类、糖类、氨基酸类以及脂类是博乐蒿根际土壤微生物群落在不同氮沉降量环境中发生变化的主要敏感碳源。(3)模拟氮沉降增加后,博乐蒿根际与非根际土壤环境因子与酶类、微生物和PAHs之间相关分析表明,根际土壤中土壤含水量、SOM、AP、pH、NH_4~+-N和NO_3~--N含量的增多对土壤中多环芳烃的含量有消减作用,与施氮前相比,养分物质的添加对根际降解PAHs具有一定促进作用;非根际土壤中AP、NH_4~+-N与NO_3~--N对PAHs去除有一定的帮助,与氮添加处理前相比,NO_3~--N的加入同样能够促进PAHs的去除。总体来看,大气中NH_4~+-N和NO_3~--N的沉降能够在短期内有效促进植物根际和非根际土壤中PAHs的去除。
[Abstract]:The degradation of pollutants in the rhizosphere of plants is a very important part of phytoremediation. It is one of the important research frontiers in soil science, botany, toxicology and environmental science. Especially in the environment of increasing nitrogen deposition, a small amount of nitrogen deposition will improve the productivity of the ecosystem and accumulate more life in the short term. The excess nitrogen deposition can lead to the excess plant nutrition, soil acidification, and the impact of the ecosystem stability. In the arid area, whether the increase of nitrogen deposition affects the degradation ability of the Polycyclic Aromatic Hydrocarbons (PAHs) in the perimeter of the petrochemical plant and the degradation mechanism and the following degradation mechanism It has a certain reference value for the remediation of soil pollution and the management and construction of the ecological environment. Through the experiment on the simulated nitrogen deposition in the vicinity of the petrochemical plant in Dushanzi District of Xinjiang, three dominant herbaceous plants of Artemisia Artemisia, dry wheat straw and four tooth mustard are analyzed. CK (no treatment), N0 (0 kg N/hm~2. A), N1 (10 kg N/hm~2. A), N2 (30 kg N/hm~2. A), five treatments (90 kg N/hm~2. A), a nitrogen addition every other month, starting from May 25, 2016 to 2016, were selected as the main research object. At the end of August 19th, the soil samples before and after nitrogen application were analyzed and compared. The results were as follows: (1) the microbial metabolic intensity of rhizosphere and non rhizosphere soil of different plants was different, and the rhizosphere soil of Artemisia Artemisia had better microbial metabolic activity (AWCD), AWCD, Simpson, and Shannon in rhizosphere soil of each plant. The evenness index (McIntosh) is greater than that of non rhizosphere soil, and the rhizosphere soil microorganism is more sensitive to carbohydrate, lipid, acid and amine carbon source, and the non rhizosphere soil microorganism is sensitive to acid, amino acid and carbohydrate source material, and the carbon source of rhizosphere soil microorganism is wider. The study shows that the existence of vegetation can promote soil. Soil enzyme activity and functional diversity improve soil microbial metabolism and functional diversity, the better the soil conditions, the more conducive to the adaptation to environmental changes. In the analysis of dehydrogenase, catalase and urease activity in the rhizosphere and non rhizosphere soils of three plants, the activities of three enzymes in the rhizosphere and non rhizosphere soil of the Artemisia Artemisia were the highest, and three kinds of plant rhizosphere soil enzymes. The correlation analysis between the soil chemical properties and the soil chemical properties showed that the main factors affecting the microbial functional diversity were pH, soil organic matter (SOM), available phosphorus (AP) and nitrate nitrogen (NO_3~--N), PAHs and EC in the rhizosphere soil, soil water content and pH, and ammonium nitrogen (NH_4~+-N) and AP in non rhizosphere soil. Increasing the removal efficiency of PAHs. (2) the increase of nitrogen deposition in the short term (3 months) enhanced dehydrogenase, catalase and urease activity in the rhizosphere soil of Artemisia Artemisia, increased AWCD, Shannon and McIntosh in rhizosphere soil, and avoided the emergence of absolute dominant species in rhizosphere microorganisms, and could better reduce the 2 ring (naphthalene) in soil. The content of 4 ring (flexion) polycyclic aromatic hydrocarbons also has a positive effect in the removal of total polycyclic aromatic hydrocarbons. In the short-term nitrogen addition treatment, the addition of 30 kg N/hm~2. A has a good promotion effect on the enzyme activity and microbial functional diversity in the rhizosphere soil of Artemisia Artemisia, especially in the removal of PAHs. The 2~5 ring is polycyclic aromatic. The content of hydrocarbons (naphthalene, phenanthrene, flexion, benzo [a] pyrene) and total polycyclic aromatic hydrocarbons (BAP) and total polycyclic aromatic hydrocarbons were significantly reduced at this nitrogen level (P0.05). The maximum utilization of six carbon source materials in the nitrogen addition treatment of 30 kg N/hm~2. A in the rhizosphere soil of Artemisia Artemisia was the most important carbon source material used in CK, N1, N2 and N3 treatment. The utilization of the rhizosphere soil microorganisms in the nitrogen free and anhydrous treatment groups was weak, indicating that the increase of nitrogen deposition could significantly change the microbial functional diversity of soil. Based on the principal component analysis, acids, carbohydrates, amino acids and lipids were different nitrogen settlements in the rhizosphere soil microbial communities of Artemisia bloomer. The main sensitive carbon sources in the environment were changed. (3) after the increase of simulated nitrogen deposition, the correlation analysis between the rhizosphere and the non rhizosphere soil environmental factors and enzymes, microorganisms and PAHs showed that the content of soil water content in rhizosphere soil, SOM, AP, pH, NH_4~+-N and NO_3~--N content increased to the content of polycyclic aromatic hydrocarbons in soil, and it was applied to the soil. Compared with nitrogen, the addition of nutrients can promote the degradation of PAHs in rhizosphere; AP, NH_4~+-N and NO_3~--N in non rhizosphere soil have some help to PAHs removal. Compared with the addition of nitrogen, NO_3~--N addition can also promote the removal of PAHs. Overall, the settlement of NH_4~+-N and NO_3~--N in large gas can be in the short term. PAHs removal in rhizosphere and non rhizosphere soil was promoted.
【学位授予单位】：新疆大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X173;X53
[Abstract]:The degradation of pollutants in the rhizosphere of plants is a very important part of phytoremediation. It is one of the important research frontiers in soil science, botany, toxicology and environmental science. Especially in the environment of increasing nitrogen deposition, a small amount of nitrogen deposition will improve the productivity of the ecosystem and accumulate more life in the short term. The excess nitrogen deposition can lead to the excess plant nutrition, soil acidification, and the impact of the ecosystem stability. In the arid area, whether the increase of nitrogen deposition affects the degradation ability of the Polycyclic Aromatic Hydrocarbons (PAHs) in the perimeter of the petrochemical plant and the degradation mechanism and the following degradation mechanism It has a certain reference value for the remediation of soil pollution and the management and construction of the ecological environment. Through the experiment on the simulated nitrogen deposition in the vicinity of the petrochemical plant in Dushanzi District of Xinjiang, three dominant herbaceous plants of Artemisia Artemisia, dry wheat straw and four tooth mustard are analyzed. CK (no treatment), N0 (0 kg N/hm~2. A), N1 (10 kg N/hm~2. A), N2 (30 kg N/hm~2. A), five treatments (90 kg N/hm~2. A), a nitrogen addition every other month, starting from May 25, 2016 to 2016, were selected as the main research object. At the end of August 19th, the soil samples before and after nitrogen application were analyzed and compared. The results were as follows: (1) the microbial metabolic intensity of rhizosphere and non rhizosphere soil of different plants was different, and the rhizosphere soil of Artemisia Artemisia had better microbial metabolic activity (AWCD), AWCD, Simpson, and Shannon in rhizosphere soil of each plant. The evenness index (McIntosh) is greater than that of non rhizosphere soil, and the rhizosphere soil microorganism is more sensitive to carbohydrate, lipid, acid and amine carbon source, and the non rhizosphere soil microorganism is sensitive to acid, amino acid and carbohydrate source material, and the carbon source of rhizosphere soil microorganism is wider. The study shows that the existence of vegetation can promote soil. Soil enzyme activity and functional diversity improve soil microbial metabolism and functional diversity, the better the soil conditions, the more conducive to the adaptation to environmental changes. In the analysis of dehydrogenase, catalase and urease activity in the rhizosphere and non rhizosphere soils of three plants, the activities of three enzymes in the rhizosphere and non rhizosphere soil of the Artemisia Artemisia were the highest, and three kinds of plant rhizosphere soil enzymes. The correlation analysis between the soil chemical properties and the soil chemical properties showed that the main factors affecting the microbial functional diversity were pH, soil organic matter (SOM), available phosphorus (AP) and nitrate nitrogen (NO_3~--N), PAHs and EC in the rhizosphere soil, soil water content and pH, and ammonium nitrogen (NH_4~+-N) and AP in non rhizosphere soil. Increasing the removal efficiency of PAHs. (2) the increase of nitrogen deposition in the short term (3 months) enhanced dehydrogenase, catalase and urease activity in the rhizosphere soil of Artemisia Artemisia, increased AWCD, Shannon and McIntosh in rhizosphere soil, and avoided the emergence of absolute dominant species in rhizosphere microorganisms, and could better reduce the 2 ring (naphthalene) in soil. The content of 4 ring (flexion) polycyclic aromatic hydrocarbons also has a positive effect in the removal of total polycyclic aromatic hydrocarbons. In the short-term nitrogen addition treatment, the addition of 30 kg N/hm~2. A has a good promotion effect on the enzyme activity and microbial functional diversity in the rhizosphere soil of Artemisia Artemisia, especially in the removal of PAHs. The 2~5 ring is polycyclic aromatic. The content of hydrocarbons (naphthalene, phenanthrene, flexion, benzo [a] pyrene) and total polycyclic aromatic hydrocarbons (BAP) and total polycyclic aromatic hydrocarbons were significantly reduced at this nitrogen level (P0.05). The maximum utilization of six carbon source materials in the nitrogen addition treatment of 30 kg N/hm~2. A in the rhizosphere soil of Artemisia Artemisia was the most important carbon source material used in CK, N1, N2 and N3 treatment. The utilization of the rhizosphere soil microorganisms in the nitrogen free and anhydrous treatment groups was weak, indicating that the increase of nitrogen deposition could significantly change the microbial functional diversity of soil. Based on the principal component analysis, acids, carbohydrates, amino acids and lipids were different nitrogen settlements in the rhizosphere soil microbial communities of Artemisia bloomer. The main sensitive carbon sources in the environment were changed. (3) after the increase of simulated nitrogen deposition, the correlation analysis between the rhizosphere and the non rhizosphere soil environmental factors and enzymes, microorganisms and PAHs showed that the content of soil water content in rhizosphere soil, SOM, AP, pH, NH_4~+-N and NO_3~--N content increased to the content of polycyclic aromatic hydrocarbons in soil, and it was applied to the soil. Compared with nitrogen, the addition of nutrients can promote the degradation of PAHs in rhizosphere; AP, NH_4~+-N and NO_3~--N in non rhizosphere soil have some help to PAHs removal. Compared with the addition of nitrogen, NO_3~--N addition can also promote the removal of PAHs. Overall, the settlement of NH_4~+-N and NO_3~--N in large gas can be in the short term. PAHs removal in rhizosphere and non rhizosphere soil was promoted.
【学位授予单位】：新疆大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X173;X53
【参考文献】
相关期刊论文 前10条
1 周嘉聪;刘小飞;郑永;纪宇v，
本文编号：2119053
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