水生植物对石佛寺人工湿地营养物质含量影响研究

发布时间：2018-06-09 16:22

本文选题：水生植物 + 石佛寺人工湿地　；参考：《沈阳农业大学》2017年硕士论文

【摘要】：本文以石佛寺人工湿地中几种代表性水生植物为研究对象,围绕湿地中的几种水生植物对于湿地营养物质含量变化的影响展开研究,分别研究了几种水生植物对于湿地整体水质中、底泥中各类营养物质含量变化的影响,并通过室内模拟实验,分析并讨论了四种生活型水生植物在死亡腐解阶段对水体与底泥中几种营养物质含量变化的影响,归纳总结出水生植物对于整个湿地营养物质含量变化的影响,并提出相应的湿地治理措施,防止湿地发生水体富营养化现象,更好的保护该湿地的生态环境。主要研究内容及成果如下:(1)采集2011-2015年石佛寺人工湿地进出水口的每月水质数据,对水生植物划分为4个生长阶段。根据植物生长的四个阶段对水体环境指标、含氧类指标、无机盐类指标的变化趋势进行分析,讨论水生植物净化水质的机理和在不同植物生长阶段对三类水体指标的影响。结果表明:水生植物在快速生长期和平稳生长期,对于水质的净化效果相对较好;养分蓄积期对于水质的净化效果最为平稳;植物的死亡腐解期,净化效果波动较大;对水质的净化机理主要有同化吸收作用、根际效应、拦截吸附作用、生化作用;对水体的净化效果与植物量有一定的关系。在养分蓄积期、快速生长期和平稳生长期阶段对水体中无机盐类具有一定的去除效果,在植物的死亡枯萎期,水生植物会增加水体中无机盐类的含量。(2)采集石佛寺人工湿地五种不同植物区域中指定点域的湿地底泥,测出底泥中OM、TN、TP三种营养物质的含量并分析。结果表明:影响湿地底泥中营养物质含量的因素有微生物因素、外源污染因素和水生植物因素。三种因素对于底泥中营养物质含量的影响在不同的植物生长期内各不相同。在植物快速生长期:底泥中营养物质受到植物生长吸收的影响最大;在植物平稳生长期:底泥中营养物质受到外界因素影响最大;在植物死亡腐解期:底泥中营养物质受到植物腐解因素的影响最大。不同的温度,对于微生物的影响不同,进而影响底泥中营养物质含量的变化。(3)对室内模拟四种生活型水生植物腐解过程进行观察,并分析腐解过程对于水质和底泥的影响及底泥对腐解产生的影响。结果表明:水生植物腐解过程中底泥对于其上覆水体中PH、DO、COD、TN、TP的变化趋势影响较小,在不同的腐解阶段,对水体中不同的指标值变化量影响不同。实验中四种生活型水生植物腐解程度与腐解速度相似,不同生活型水生植物腐解过程对于水环境的影响程度不同,会使水体中PH值、TN和TP含量升高;对水体中DO和COD含量的影响不相同,但水体中两者的初末含量变化呈负相关性变化。腐解过程促进了底泥对C和TN的向外释放,降低底泥底泥中C和TN的含量,起到防止底泥中营养物质沉积的作用,而对于TP的作用相反。
[Abstract]:In this paper, several representative aquatic plants in Shifosi constructed wetland were taken as the research object, and the effects of several aquatic plants on the changes of nutrient content in the wetland were studied. The effects of several aquatic plants on the changes of nutrient contents in the sediment and water quality of the wetland were studied, and the indoor simulation experiments were carried out. The effects of four living aquatic plants on the changes of nutrient contents in water and sediment were analyzed and discussed, and the effects of aquatic plants on the changes of nutrient contents in the whole wetland were summarized. In order to prevent the eutrophication of the wetland and protect the ecological environment of the wetland, the corresponding wetland treatment measures are put forward. The main research contents and results are as follows: (1) the monthly water quality data of the inlet and outlet of Shifosi constructed wetland from 2011-2015 are collected, and the aquatic plants are divided into four growth stages. According to the four stages of plant growth, the change trend of water environment index, oxygen content index and inorganic salt index is analyzed, and the mechanism of aquatic plants purifying water quality and the influence of different plant growth stages on three kinds of water body indexes are discussed. The results showed that the purification effect of aquatic plants on water quality was relatively good in the rapid growth period and steady growth period, the purification effect was most stable in nutrient accumulation period, and the purification effect fluctuated greatly in the decaying stage of plants. The purification mechanism of water quality mainly includes assimilation and absorption, rhizosphere effect, interception adsorption, biochemical action, and the purification effect of water body has certain relationship with plant quantity. In nutrient accumulation period, rapid growth period and steady growth stage, inorganic salts in water were removed to a certain extent, and plants died and withered. Aquatic plants can increase the content of inorganic salt in water body. (2) collect wetland sediment from five different plant areas of Shifosi constructed wetland, measure the content of three nutrients of OMTNN TP in sediment and analyze them. The results showed that the factors affecting the content of nutrients in wetland sediment were microorganism factor, exogenous pollution factor and aquatic plant factor. The effects of three factors on the nutrient content in sediment were different in different plant growth periods. In the period of rapid growth of plants, nutrients in sediment are most affected by plant growth and absorption, and in stable growth of plants, nutrients in sediment are most affected by external factors. In the stage of plant death, nutrients in sediment were most affected by the factors of plant decay. The effects of different temperature on microorganism and the change of nutrient content in sediment were observed. The influence of the degradation process on the water quality and sediment and the influence of the sediment on the degradation are analyzed. The results showed that the sediment had little effect on the change trend of PHDOD TNTP in the overlying water during the decomposition of aquatic plants, and had different influence on the change of the index value in the different stages of decomposition. In the experiment, the degree of decomposition of four kinds of living aquatic plants is similar to the speed of decomposition. The degradation process of different types of aquatic plants has different influence on the water environment, which will increase the contents of PH, TN and TP in water. The effects on the contents of do and COD in water were different, but the changes of initial and final contents of do and COD in water showed negative correlation. The decomposing process can promote the release of C and TN, decrease the contents of C and TN, and prevent the deposition of nutrients in the sediment, but the effect on TP is opposite.
【学位授予单位】：沈阳农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X173;X52

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