铁尾矿土壤化利用过程中重金属污染的植物修复和土壤改良技术

发布时间：2018-04-14 05:31

本文选题：铁尾矿 + 重金属污染　；参考：《山东大学》2017年硕士论文

【摘要】：我国铁矿采选业的快速发展,造成铁尾矿和废石的产排放量急剧增加,由于其综合利用率低,导致铁尾矿和废石堆存量不断增加,环境污染和生态破坏风险显著增高。因此,铁尾矿的大规模资源化利用以及污染控制对于突破行业技术瓶颈具有重要的意义。植物修复技术具有修复成本低、修复效果好、现场扰动少、易与其它修复技术相结合等诸多优点,是一项发展前景广阔的修复技术。本研究在全面查阅和系统分析国内外相关研究的基础上,以鞍山矿业集团有限公司大孤山尾矿库的选矿尾渣(铁尾矿)和采矿废石(废石)为研究对象,通过植物盆栽实验和现场应用等手段,开展了铁尾矿土壤化利用过程中的植物修复技术研究,一方面是改良铁尾矿的理化性质,破解其透气保水性差、有机质含量低、盐碱度高等技术难题,另一方面是控制消除铁尾矿土壤化过程中的重金属污染风险,实现工程化应用。研究结果如下:(1)通过全面调查鞍山地区植物资源的分布,结合国内外植物修复的相关研究基础,确定了紫花苜蓿(Medicag sativa L.),地肤(Kochia scoparia(L.)Schrad.)和碱蓬(Suaeda glauca)作为本次植物修复技术研究的典型实验植物。(2)在系统调查和现场监测的基础上,确定了 Cd、Pb、Mn作为本次研究的目标金属元素。利用铁尾矿(或废石),通过添加重金属配置一系列浓度梯度的Cd、Pb、Mn模拟污染土壤,采用盆栽实验方法,通过测定植物成熟后的地上生物量、叶绿素含量和叶片内过氧化氢酶的活性等指标,研究不同植物对铁尾矿土壤化利用过程中特殊环境的适应性,结果表明:少量的Cd、Mn会刺激紫花苜蓿的生长,而高浓度的重金属则产生明显的抑制作用;碱蓬和地肤的地上生物量随着重金属浓度的增加而递减。三种植物的叶绿素含量均随着重金属浓度的增加而减少;而三种植物叶片内过氧化氢酶活性则均呈先升高后降低的趋势,而且均高于对照。(3)采用盆栽植物实验室模拟方法,研究了不同植物对铁尾矿土壤化利用的理化性质改良效果,结果表明:三种植物均显现出明显的改良效果,其中紫花苜蓿、地肤和碱蓬改良的土壤有机质含量最大增长率分别为48.9%、44.8%和38.7%;土壤过氧化氢酶的最大增长率分别为66.7%,85.4%和72.7%。地肤和碱蓬改良的土壤pH值降低了 0.4个单位,紫花苜蓿改良土壤降低0.2个单位,对尾矿土壤的碱性有明显改善作用。土壤含水率均提高了 2.0%左右,紫花苜蓿、地肤和碱蓬土壤最大含水率分别达到9.4%、9.5%和9.1%,达到了种植土壤的要求。(4)通过测定植株体内以及土壤中Cd、Pb和Mn含量,评价三种植物对重金属的耐受性、富集能力以及土壤重金属污染修复能力。结果表明:三种植物对重金属Cd的富集修复能力依次为:碱蓬紫花苜蓿地肤,且碱蓬和紫花苜蓿可作为高浓度Cd污染土壤的修复植物;对Pb的富集能力依次为:地肤碱蓬紫花苜蓿;对Mn的富集修复能力依次为:碱蓬地肤紫花苜蓿。三种植物对Cd、Pb、Mn的耐受性和富集吸收能力各不相同,分别表现为紫花苜蓿和碱蓬对Mn富集效果较好,其次是Cd和Pb,而地肤对Pb富集效果较好,其次是Mn和Cd。(5)根据实验室研究结果,结合课题组其它研究成果,采用地肤、经济作物大豆和五彩石竹三种植物进行工程化现场应用,通过定期监测植物生长情况和相关指标,验证植物修复技术对土壤改良和重金属污染的修复效果。实验室内以及第三方监测结果表明:尾矿综合理化性质得到明显改善,pH值降低0.6个单位左右,含水率提升约50%,有机质提高70%～109%,地肤、大豆株高达98cm、82cm,五彩石竹覆盖率达100%。同时尾矿中主要重金属污染也得到有效控制。Cd、Pb、Mn、Zn 和 Cu 去除率达到 13%～49%。
[Abstract]:The rapid development of China's iron ore mining industry, producing emissions caused by iron tailings and Fei Shi increased sharply, because of its comprehensive utilization rate is low, resulting in iron tailings and waste rock stock increased significantly increased the risk of environmental pollution and ecological destruction. Therefore, large-scale resource utilization of iron tailings and pollution control for breakthrough technology industry the bottleneck is of great significance. With plant repair technique of low cost, good repair effect, less disturbance, and other advantages of easy repair technology combination, repair a broad prospects for development. Based on the comprehensive analysis and inspection system related research at home and abroad, the ore dressing tailings tailings Anshan Mining Group Co. Ltd. (Dagushan iron tailings) and mining (Fei Shi Fei Shi) as the research object, through the potted plant experiment and field application of means to carry out iron tailing soil Study on phytoremediation technology utilization in the process, one is the physical and chemical properties of modified iron tailings, crack the permeability of bad water retention, low organic matter content, salinity and higher technical problems, on the other hand is to control the elimination of iron tailings soil in the process of the risk of heavy metal pollution, realize the engineering application of the results. Are as follows: (1) the distribution of comprehensive investigation of plant resources in Anshan area, based on the related research at home and abroad of phytoremediation, the alfalfa (Medicag sativa L.), broomsedge (Kochia scoparia (L.) Schrad. (Suaeda) and Suaeda glauca) as a typical experimental plant research the phytoremediation technology. (2) based on system investigation and monitoring on the determination of Cd, Pb, Mn as the target of metal elements in this study. Using iron tailings (or rock), by adding a series of configuration heavy metal concentrations of Cd, Pb, Mn pollution simulation The soil by pot experiment method, through the determination of mature plants aboveground biomass, chlorophyll content and leaf catalase activity index, using special environment in the process of adaptation of different plants to iron tailings soil showed that a small amount of Cd, Mn will stimulate the growth of alfalfa, and high heavy metals the concentration is obviously inhibit; Suaeda salsa and Kochia scoparia aboveground biomass decreased with the increase of heavy metal concentration. The chlorophyll content of the three plants were decreased with the increase of heavy metal concentration; catalase activity in leaves of three species were first increased and then decreased, but were higher than the control. (3) simulation method using potted plants of different plants showed that the laboratory utilization of iron tailings soil physicochemical properties improvement, results: three plants are showing obvious change In effect, the maximum growth of alfalfa, the content of soil organic matter and improved Suaeda Kochia scoparia rate were 48.9%, 44.8% and 38.7%; the maximum growth rate of soil catalase were 66.7%, 85.4% and 72.7%. and soil pH value improved Suaeda Kochia scoparia was decreased by 0.4 units, alfalfa soil decreased 0.2 units. The alkaline tailings soil is improved obviously. The soil water content was increased by about 2%, alfalfa, Kochia scoparia and Suaeda salsa maximum soil moisture content reached 9.4%, 9.5% and 9.1%, reached the soil requirements. (4) through the determination of plant and soil Cd, Pb and Mn content, tolerance three evaluation of heavy metals in plants, and the enrichment ability of heavy metal contaminated soil. The results showed that the three species of heavy metal enrichment of Cd repair capacity is as follows: alfalfa and Suaeda salsa broomsedge, and m. Alfalfa can be used as a repairing plant with high concentration of Cd contaminated soil; the enrichment ability of Pb is as follows: the ability of Suaeda Kochia scoparia alfalfa; enrichment Mn repair is as follows: three. Alfalfa broomsedge Suaeda plants to Cd, Pb, Mn tolerance and accumulation abilities vary, respectively for the performance of good alfalfa and Suaeda salsa on Mn enrichment effect, followed by Cd and Pb, and broomsedge enrichment to Pb good effect, followed by Mn and Cd. (5) according to the results of laboratory research, in combination with other research results, the engineering application of broomsedge, three species of crop soybean and Caryophyllaceae, through regular monitoring of the plant the growth situation and related indicators, verify the repairing effect of phytoremediation of soil and heavy metal pollution. In the lab and third party monitoring results show that the physical and chemical properties of tailings has been significantly improved, pH value decreased 0.6 Unit about water content increased by approximately 50%, organic matter increased by 70% ~ 109%, Kochia scoparia, soybean plant height was 98cm, 82cm, Caryophyllin coverage of 100%. and the main pollution of heavy metals in tailings can be controlled effectively in.Cd, Pb, Mn, Zn and Cu removal rate reached 13% ~ 49%.

【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S156;X53

【参考文献】