锰矿污染区植物群落模式修复效应研究

发布时间：2018-01-11 12:42

  本文关键词：锰矿污染区植物群落模式修复效应研究　出处：《中南林业科技大学》2017年博士论文　论文类型：学位论文

  更多相关文章： 锰矿污染区 生态修复工程 泡桐 栾树 植物群落 有机菌肥 热力学方程

【摘要】：本文以湘潭锰矿污染区治理为研究对象,致力于探索重金属污染场地生态修复涉及的理论与工程技术问题。通过野外调查和样品采集,分析了锰矿渣堆积区基质的理化性质与重金属污染程度,统计了区内分布的本土植物种类,分析了其重金属耐受和积累特性,选出了 16种生态-经济型修复植物。采用矿渣作为基质开展了盆栽试验,测试分析了筛选植物耐受复合重金属污染的机理,检验了专用有机菌肥改良根际土壤的效果。结合盆栽试验,构建了中试模拟场地试验装置,对比了复合与单一植物模式的修复效应。基于上述研究,以泡桐和栾树为建群植物,采用专用有机菌肥改良根际土壤微生态环境来代替常规的覆土方法,成功地在湘潭锰矿污染区建立了面积为4 hm2的生态修复示范区。示范区建成后5年里,通过采样、监测,比较了泡桐和栾树5年生长量和重金属积累特性,分析了逐步形成的植物群落结构和其重金属吸收的季节变化效应。结合运用物理化学与生态学原理,建立了用以描述重金属污染修复区状态的生态系统热力学方程,测试分析了不同植物群落模式的Gibbs自由能和不同物种的化学势。本研究为指导生态修复工程实践和评价污染区生态修复效果提出了新的理论依据与实用参数。主要研究结果如下:(1)湘潭锰矿渣基质保水性差,氮、磷含量低,不利于植物生长。基质中最高Mn含量可达24727.73 mg/kg,Pb、Cd、Cu、Zn的平均含量也远超过湖南省和全国的背景值。污染指数、地累积指数和潜在生态风险指数评价结果表明,试验点属多重金属重度污染区,存在极大的潜在生态风险。矿区本土植物共63种29科,多为草本植物。盆栽筛选试验中,泡桐、乌桕、蓖麻、栾树、小叶女贞、红麻、夹竹桃成活率均达100%,7种植物中,泡桐和栾树生长速度最快,泡桐、栾树、红麻、夹竹桃的Mn、Pb积累量大,专用有机菌肥显著增大了植物生物量和锰吸收量,含20%有机菌肥基质处理的成本效益最高。(2)中试模拟试验中,复合植物模式的生物量、Mn积累量、持水量分别是单一植物模式的1.6、7.5、1.5倍,有机菌肥能增大群落重金属吸收量,提高基质保水能力,降低重金属污染扩散量。模拟降雨淋失试验中,有机菌肥处理提高了土壤水溶性Mn含量,但降低了其络合性重金属含量,系统水土流失和随其带走的重金属量随模拟降雨强度增大而增大。要控制污染扩散,必须拦截阻隔降雨时期污染区的水土流失。复合植物-有机菌肥处理的植物覆盖度、生物量、重金属积累量最大,生态修复效果最好,形成的乔-灌-草空间结构具有生物多样性丰富,保水力强和水土流失量低的综合特点。(3)生态修复示范区中,专用有机菌肥处理区栽种的泡桐和栾树的成活率大于83%,利用其速生特点,能快速恢复污染区植被景观。3至5年树龄的泡桐平均树高、胸径、生物量、重金属积累量均大于栾树。两种植物重金属积累量随树龄显著增大,在植体内的分布规律为茎根叶。两种植物的Mn、Pb含量随树龄的变化不大,在植体内的分布规律为叶根儢。复合植物群落的密度、盖度、丰富度、多样性指数的季节变化显著,规律为夏秋与春冬。由于落叶和草本植物的消亡,植物群落地上部生物量和重金属吸收量随季节变化的规律为秋夏冬≈春。处理区根际土壤Mn水溶性季节规律为夏、秋和冬大于春季,土壤微生物数量和种类数为秋和夏大于春和冬季。植物的生长量和锰积累量与土壤重金属有效性和工程区植物多样性呈正相关。(4)监测的植物修复模式中,复合植物群落模式的覆盖度、丰富度、多样性指数、均匀度最大。不同模式植物的平均年生物量增长率为:复合植物-有机菌肥单一草坪-覆土单一栾树-覆土对照;植物锰吸收量为:复合植物-有机菌肥单一栾树-覆土对照单一草坪-覆土。复合植物-有机菌肥模式的群落层次丰富度和多彩美景度最高,景观效果最好。(5)本研究定义的转运量系数TQ和积累量系数BQF可定量描述植物的重金属转运和去除能力,而建立的生态系统Gibbs自由能方程可用以确定工程区生态系统的状态和评价修复的效果。植物群落自由能和化学势描述的生态修复效应与相关生态学指标反映的基本趋势一致,复合植物-有机菌肥模式的锰吸收量的Gibbs自由能值最高、富集锰元素的势能最强。自由能G包含了系统生产力和生物多样性信息,化学势μ能反映植物生长势、元素吸收能力及其相关的生态学特性。与传统指标相比,G和μ可从热力学角度分析生态系统与立地环境的相关性,因此,建立的热力学方程在指导生态修复工程实践和评价修复效果中具有一定的应用价值。本文主要的创新点为:(1)采用用材树种为建群物种,发展了新的用以修复重金属污染场地的植物群落模式技术。(2)应用了具有解毒和供肥功能的含有耐性菌株的有机菌肥。(3)建立了用以确定生态修复工程区植物群落自由能和化学势的热力学方程。
[Abstract]:Based on the governance of Xiangtan manganese polluted area as the research object, aims to explore the ecological restoration of heavy metal contaminated sites involved in theory and engineering technology. Through field investigation and sample collection, analysis of the manganese slag accumulation area of matrix and the physicochemical properties of heavy metal pollution in the area, the distribution of native plant species and its analysis heavy metal tolerance and accumulation characteristics, selected 16 kinds of eco economic type repair plants. Using slag as substrate in the pot experiment carried out, test analysis of the mechanism of screening of complex heavy metal pollution tolerance in plants, the special inspection of rhizosphere soil organic fertilizer improved effect. With the pot experiment, establishes the simulation test site test equipment repair effect of composite and single plant model. Based on the above research, with Paulownia edificatos and Koelreuteria plants, using special fertilizer improved rhizosphere soil micro organic Instead of the conventional method of soil ecological environment, successfully in Xiangtan manganese polluted area was established as the demonstration zone of ecological restoration area of 4 hm2. 5 years after the completion of the demonstration area, through sampling, monitoring, comparison of the 5 annual growth of Paulownia and Koelreuteria and heavy metals accumulation characteristics, analyzes the effect of seasonal variation of plant community structure step by step and the formation of the heavy metal absorption. Combined with the use of physical chemistry and ecology principle, ecological system is established to describe the state of thermodynamic equation for remediation of heavy metal contaminated area, test analysis of different plant community patterns of Gibbs free energy and chemical potential of different species is proposed. The theoretical basis and practical parameters of the new study the guidance of ecological restoration engineering practice and assessment of pollution of ecological restoration. The main results are as follows: (1) Xiangtan manganese slag matrix of bad water retention, low nitrogen, phosphorus content, unfavorable to plant growth. The matrix can reach the highest content of Mn 24727.73 mg/kg, Pb, Cd, Cu, the average content of Zn is far better than the Hunan province and the national background value. The pollution index, geoaccumulation index and potential ecological risk evaluation index showed that the test point is more severe heavy metal pollution area, there is great potential ecological risk. Mining of native plants a total of 63 species of 29 families, mostly herbaceous plants. Pot tests, Paulownia, Sapium, castor, Koelreuteria paniculata, Ligustrum quihoui, kenaf, the survival rate of oleander reaches 100%, 7 kinds of plants, and for the fastest growth of Paulownia, Paulownia, Luan tree, kenaf, oleander Mn, Pb accumulation special, manure fertilizer significantly increased the plant biomass and Mn uptake, containing 20% organic bacterial manure treatments cost-effective. (2) in the simulation experiment, the biomass composite plant model, the accumulation of Mn, the water holding capacity were 1.6,7.5,1.5 times higher than that of single plant model, Organic fertilizer can increase the uptake of heavy metals to improve community, matrix water retention capacity, reduce the heavy metal pollution diffusion amount. The simulated rainfall leaching test, manure fertilizer treatment increased soil water soluble Mn content, but reduced its complexing heavy metal content, soil erosion and the system with taking heavy metals increases with rainfall intensity increased. To control the spread of pollution to soil erosion rainfall interception barrier area. The organic pollution in fertilizer plant compound plant coverage, biomass, accumulation of heavy metals in the largest amount, the best effect of ecological restoration, the formation of Joe irrigation grass spatial structure with abundant biodiversity and comprehensive characteristics of soil and water conservation is strong low loss. (3) ecological restoration demonstration area, special organic fertilizer and planting area of Paulownia Koelreuteria survival rate more than 83%, with its fast-growing characteristics, can be quickly restored polluted area Paulownia tree vegetation landscape average.3 to 5 years of age, DBH, biomass, heavy metal accumulation was greater than two. Koelreuteria heavy metal accumulation in plants was significantly increased with age, the distribution of planting in order of stem leaf and root. Two species of Mn, Pb content changes little with age, in distribution for the implantation of leaf Genlv. Compound plant density, coverage, abundance, seasonal variation of diversity index is significant, for summer and winter and spring. The law due to the demise of herbaceous plants and deciduous plants, above ground biomass and heavy metal uptake with seasonal variation rules for summer autumn and winter is spring. Root processing area soil water soluble Mn seasonal pattern for the summer, autumn and winter than in spring, soil microbial quantity and species number is greater than the spring and summer autumn and winter. The growth and accumulation of manganese plant diversity and soil heavy metal availability and plant in engineering area Positive correlation. (4) phytoremediation mode monitoring, coverage, compound plant model species richness, diversity index, evenness. Different patterns of the average annual growth rate of biomass: composite plant turf soil organic bacterial manure single single - soil of Koelreuteria paniculata; manganese absorption plant quantity: the compound organic fertilizer plant - soil single Koelreuteria controlled single lawn - soil composite plant community richness. Organic pattern and colorful beauty of fertilizer is the highest, the landscape effect is the best. (5) TQ transportation coefficients of this study and the definition of the accumulation coefficient BQF can quantitatively describe the heavy metal transport in plants and the removal ability, and the establishment of the ecological system of Gibbs free energy equation can be used to determine the effect of state and evaluation of ecosystem engineering area. The plant community restoration of free energy and chemical potential to describe the effect of ecological restoration and ecological indexes The same basic trend reflects the energy value of the maximum amount of Gibbs free composite plant model of manganese absorption of organic fertilizer, the strongest enrichment of manganese. The potential free energy G includes system productivity and biodiversity information, chemical potential can reflect plant growth, absorption capacity and ecological characteristics. Compared with the traditional correlation index, correlation, G and analysis of ecosystem and environment from the view of thermodynamics and thermodynamic equation has certain application value in guiding the practice of ecological restoration projects and to evaluate the repair effect. The main innovation of this paper is: (1) the timber species edificatos species, with the development of new to plant community mode technology remediation of heavy metal polluted sites. (2) applied with the function of detoxification and fertilizer containing organic fertilizer tolerance strains. (3) to establish the ecological restoration areas for The thermodynamic equation of the free energy and chemical potential of a plant community.

【学位授予单位】：中南林业科技大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：X173;X757
，

本文编号：1409593