湿地植物对磷与重金属去除的根际效应及机理研究

发布时间：2018-04-21 14:17

本文选题：湿地植物 + 根表铁膜　；参考：《浙江大学》2017年博士论文

【摘要】：人工湿地是一种生态治理污水的新技术,在我国被广泛应用于处理生活污水、工业废水及矿山废水等。湿地植物作为人工湿地的重要组成部分对污染物的去除起了重要的作用。在以往的研为究中,为了生产的需要,对于湿地植物根际的研究主要集中在水稻上;一些有关湿地植物的根际研究也集中在根表铁膜形成与养分吸收的关系上,而对于湿地植物根际环境与除污功能的系统研究较少,因此,研究湿地植物根际效应与污染物去除的关系,在实践上可为湿地植物种类的选择、优化湿地环境条件、提高湿地除污效率与稳定性、延长湿地运行寿命等提供理论依据;在理论上,可以探明湿地植物去除磷与重金属的途径,丰富人工湿地的除污机理。本研究根据植物的易得性和易栽培性,收集了杭州地区常见的15种湿地植物,通过对这些湿地植物的根系氧化力、根形态、营养元素吸收能力等特征的研究,筛选出在除污能力、生理生化性状差异大的植物,以此为材料,研究湿地植物根表铁膜的形成机理及其对磷与重金属元素的吸附、吸收及转运的作用,并研究了湿地植物的根际生物、微生物学特性,主要研究结果如下:1.湿地植物生长与生理特性及氮磷吸收能力根据植物的易得性和易栽培性,选取了杭州地区常见的15种湿地植物,研究这些湿地植物的根系氧化力、根形态、营养元素吸收能力等特征,结果发现:15种湿地植物的生物量差异较大,美人蕉(Canna generalisL.)、宽叶香蒲(Typha latifolia 1L.)、再力花(Thalia dealbata F.)和千屈菜(Lythrum salicaria L.)4 种植物的生物量较大。15种湿地植物在水培条件下对N、P的吸收和积累上表现出显著的差异,植物体内的N、P含量与植物的生物量、根系表面积、根系氧化力等呈显著相关。美人蕉、宽叶香蒲、再力花对溶液中NH4+-N、NO3--N和P的去除率较高,且对N、P在体内的积累量也较高,对污染水体中营养物的净化效果明显。2.湿地植物根表铁膜的形成动态及特性通过对15种湿地植物进行添加200 mg·L-1 Fe 2+(FeS04·7H20)培养4 d和8 d,结果发现,美人蕉、宽叶香蒲和再力花都有较大的根表面积(1400cm2),15种湿地植物形成的根表铁膜数量与根表面积、根尖数成显著正相关,而与根系氧化力相关关系不显著。在添加外源亚铁处理4d时,植物根表铁膜上的Ca,Cu,Zn和P的量与铁膜数量显著相关,处理8 d后则呈极显著相关。植株根系吸收的Ca,Cu,Zn和P的量与铁膜数量无论是培养4 d还是8 d都显著相关,而地上部则无相关性。3.湿地植物根表铁膜与磷、重金属吸收的关系通过前期实验,选取美人蕉和垂穗莎草(Cyperus.nutans V.)两种湿地植物为研究对象,通过添加不同浓度外源亚铁诱导根表铁膜的形成,研究了溶液中的铁对根表铁膜的形成的影响及铁膜对P,Cu,Cd,Zn和Pb的吸附及在植物体内转运的影响。结果发现,湿地植物根表铁膜数量的形成受溶液中的亚铁离子浓度和植物种类的影响,美人蕉与垂穗莎草的根表铁膜数量与外源亚铁浓度呈非线性相关,当溶液中的亚铁离子浓度为50-80 mg·L-1时形成的铁膜的数量最多,两种植物中美人蕉形成的铁膜数量较多。采用差速离心技术分离美人蕉和垂穗莎草各部分细胞器,检测不同处理时间下各细胞器中Pb的含量,通过Pb在组织、细胞中的分布状态研究植物根表铁膜对美人蕉和垂穗莎草等湿地植物体内Pb的积累和转运的影响,结果发现,Pb在这两种植物的各器官中的含量细胞壁所占的比重最高,细胞器所占的比重最低。根表铁膜抑制了两种湿地植物地下部对Pb的吸收,而促进了地上部对它们的转运。4.模拟人工湿地条件下湿地植物根际特性以美人蕉、香蒲(Typha orientalis L.)、垂穗莎草、玉带草(Reineckia carnea L.)为材料,研究了在模拟人工湿地条件下湿地植物根际与非根际土壤中的微生物数量、种群、土壤酶活性。结果表明,4种湿地植物的根际微生物生物量均显著大于非根际环境,根际效应显著。不同湿地植物根际酶活性显著高于非根际环境,说明湿地植物根际效应加速了 N、P的转化。4种湿地植物根际土壤有效态磷、锰、铜、锌的含量都高于非根际土壤,表明了植物根系对这些元素的活化效应。
[Abstract]:Constructed wetland is a new technology for ecological treatment of sewage. It is widely used in the treatment of domestic sewage, industrial wastewater and mine waste water in China. Wetland plants play an important role in the removal of pollutants as an important part of the constructed wetland. In the past research, for the needs of production, the rhizosphere of wetland plants The research is mainly concentrated on rice, and some studies on the rhizosphere of wetland plants also focus on the relationship between the formation of iron membrane and nutrient absorption of the root surface, but the systematic research on the rhizosphere environment and the decontamination function of the wetland plants is less. Therefore, the study of the relationship between the rhizosphere effect and the removal of pollutants in the wetland plants can be used in practice for the species of wetland plants. Selection, optimizing the environmental conditions of wetland, improving the efficiency and stability of wetland, and prolonging the operating life of the wetland. In theory, we can find out the ways to remove the phosphorus and heavy metals by the wetland plants and enrich the mechanism of the pollution removal in the artificial wetland. This study collects the common in Hangzhou area according to the availability and the easy cultivation of the plants. The 15 kinds of wetland plants, through the study of the characteristics of root oxidation, root morphology and nutrient absorption capacity of these wetland plants, screened out the plants that have the ability to remove pollution and have large differences in physiological and biochemical characters. This is the material to study the formation mechanism of the iron membrane in the root surface of wetland plants and the adsorption, absorption and transport of phosphorus and heavy metals. The results are as follows: 1. the main results are as follows: 1. the growth and physiological characteristics of the wetland plants and the ability to absorb nitrogen and phosphorus, according to the availability and the easy cultivation of plants, select 15 kinds of common wetland plants in Hangzhou area, and study the root oxidation, root morphology and nutrient element of these wetland plants. The results showed that the biomass of the 15 kinds of wetland plants was different, the Canna generalisL., the wide leaf cattail (Typha latifolia 1L.), the Thalia dealbata F. (Thalia dealbata F.) and the Lythrum salicaria L. (Lythrum salicaria L.) were used to absorb and accumulate in the hydroponic condition. The content of N and P in plants showed significant correlation with plant biomass, root surface area and root oxidation. Canna, broad leaf cattail, and reforce flower had higher removal rate of NH4+-N, NO3--N and P in the solution, and N, P in the body was also higher in the body, and the purification effect of nutrients in polluted water body was.2. wetland. The formation dynamics and characteristics of the plant root surface iron membrane were obtained by adding 200 mg. L-1 Fe 2+ (FeS04. 7H20) to 4 D and 8 d. The results showed that Canna, cattail and reforce flower had large root surface area (1400cm2). The number of iron membrane formed in the 15 species of wetland plants was significantly correlated with the root surface area and the root tip number. When adding exogenous ferrous treatment 4D, the amount of Ca, Cu, Zn and P on the iron membrane of the plant root surface was significantly correlated with the quantity of iron film, and the amount of Ca, Cu, Zn and P absorbed by plant roots was significantly related to the number of iron film in the cultivation of 4 d or 8 D, while the upper part was not in phase. The relationship between the iron membrane of the root surface of the.3. wetland plant and the phosphorus and the absorption of heavy metals was studied by the previous experiments. Two kinds of wetland plants were selected as Canna and Cyperus.nutans V.. The iron film in the root surface of the root surface was studied by adding different concentrations of exogenous ferrous iron to the formation of the iron membrane. The effects of the adsorption of P, Cu, Cd, Zn and Pb on the transport in plants. The results showed that the formation of iron membrane in the root surface of the wetland plants was influenced by the concentration of ferrous ions and the plant species in the solution. The number of iron membrane in the root surface of Canna and panicle was not linearly related to the concentration of exogenous ferrous, when the concentration of ferrous ions in the solution was 50-80 mg. The number of iron film formed at L-1 was the most, the number of iron film formed by the two species of Sino-American plantain was more. The cell organelles of Canna and panicle were separated by differential centrifugation, and the content of Pb in various organelles was detected at different processing times. The iron membrane of plant root surface was used to study Canna and Canna through the distribution of Pb in tissue and cells. The effect of Pb accumulation and transport in marsh plants, such as sedge, showed that Pb had the highest proportion of cell walls in each organ of these two plants, and the proportion of organelles was the lowest. The root surface iron membrane inhibited the absorption of Pb in the subsurface of two species of wetland plants, and promoted the transfer of.4. in the upper part of the ground. Under the conditions of wetland, the rhizosphere characteristics of wetland plants are Canna Canna, Typha orientalis L., panicle sedge, and Reineckia carnea L. as materials. The microbial number, population, and soil enzyme activity in the rhizosphere and non rhizosphere soil of wetland plants were studied under simulated artificial wetland. The results showed that the rhizosphere of 4 wetland plants was microbiological. The rhizosphere effect of different wetland plants was significantly higher than that of non rhizosphere. The rhizosphere enzyme activity of different wetland plants was significantly higher than that of non rhizosphere, which indicated that the rhizosphere effect of wetland plants accelerated N, and the content of available phosphorus, manganese, copper and zinc in the rhizosphere soil of.4 species wetland plants was higher than that of non rhizosphere soil, which showed that plant roots to these elements to these elements. Activation effect.

【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：X173;X703

【相似文献】