恢复湿地中磷的空间分布格局与垂向迁移转化机制研究

发布时间：2018-05-12 00:37

本文选题：七星湖湿地 + 水生植物　；参考：《华北电力大学(北京)》2017年硕士论文

【摘要】：探索磷在恢复湿地中的迁移转化及内源磷的释放风险对研究湿地系统磷去除机理具有重要意义。本文以山东滕州市七星湖湿地为研究区域,采集了湿地表层水体、大型水生植物、沉积物及其上覆水体样品,分析了磷的沿程分布规律,研究了环境因素对磷空间分布格局的影响。在此基础上,探讨了磷的垂向迁移转化机制,计算了沉积物-上覆水体扩散通量,并分析了底泥沉积物磷的释放风险。研究结果表明,(1)在湿地中,各形态磷的污染负荷存在沿程下降的趋势。1)表层水体溶解性活性反应磷(SRP)浓度沿程降低,磷污染负荷在明水区域削减80%,在芦苇群落削减94%,在香蒲群落削减91%,水生植被有显著的SRP去除效果;在中游区段,表层水体的磷形态主要是颗粒磷(PP),植物群落PP百分比低于明水区域。对表层水体各形态磷影响最大的理化性质是酸碱度(pH)和溶解氧(DO)。2)上覆水体SRP浓度沿程降低,磷污染负荷在芦苇群落削减91%,在香蒲群落削减94%,削减幅度高于明水区域(81%);PP百分比在入口处较低,随后在中游区段增大。对上覆水体各形态磷影响最大的理化性质是pH。3)在沿程多数断面,间隙水各形态磷浓度在明水区域中比植物群落中高,间隙水主要以SRP为主,占总磷(TP)的46%~91%。对间隙水各形态磷影响最大的理化性质是pH和电导率(C)。4)在湿地入口处,明水区域的沉积物TP含量较高,达到1234.7 mg/kg,高于同一断面的芦苇群落和香蒲群落。在湿地出水口,明水区域沉积物TP含量降低,而植物群落沉积物TP含量仍处于较高水平。有机质含量与沉积物TP含量有显著正相关关系。碱性磷酸酶活性与有机磷含量有显著负相关关系。5)芦苇在L1断面株高较高,但磷吸收量却不高。而在X3断面香蒲茎粗最小(20.18 cm),体内磷含量却高达2.74g/kg。(2)明水区域和植物群落存在不同的垂向迁移转化机制。1)明水区域、芦苇群落和香蒲群落垂向断面中,TP、TDP、SRP主要分布在上覆水体和间隙水中。TP、TDP、SRP在植物群落进水口处主要存在于上覆水体中,间隙水所占比例较低。2)湿地磷主要富集在沉积物中,在水体-植物-沉积物中所占比例为95%以上,其次是植物,最低是水体。3)明水区域间隙水各形态磷与沉积物NaOH-P具有显著相关关系;芦苇群落表层水体和上覆水体、间隙水和沉积物有机磷有显著相关关系;香蒲群落表层水体和上覆水体、上覆水体和间隙水有显著相关性。4)湿地磷素由沉积物向上覆水体扩散。湿地表层沉积物吸附指数(PSI)在湿地中整体表现出前段低后段高的分布特征,说明湿地前段沉积物磷最大吸附量相对较小。植物群落表层沉积物吸附饱和度(DPS)高于明水区域,PSI低于明水区域,表明植物群落表层沉积物磷更容易进入上覆水体。利用磷释放风险指数(ERI)对湿地表层沉积物中的磷的潜在释放风险进行评估,结果表明湿地表层沉积物中磷释放风险处于高度风险范围,其中香蒲群落磷释放风险最高。在恢复湿地中,磷素由沉积物向上覆水体扩散,具有高度的磷释放风险;植物群落中水体各形态磷浓度和沉积物富集磷素均比明水区域低,植物可以降低区域磷污染负荷。本研究进一步正确认识和评估湿地水质净化功能,为科学规划恢复湿地污水处理生态工程提供依据。
[Abstract]:Exploring the migration and transformation of phosphorus in the restoration wetland and the risk of releasing endogenous phosphorus is of great significance to the study of the mechanism of phosphorus removal in the wetland system. This paper took the Seven Star Lake Wetland in Tengzhou, Shandong as the research area, and collected the surface water body of the wetland, the large aquatic plants, the sediments and the overlying water samples, and analyzed the distribution regularity of the phosphorus in the process. The influence of environmental factors on the spatial distribution pattern of phosphorus was investigated. On this basis, the vertical migration and transformation mechanism of phosphorus was discussed, the diffusion flux of sediment and overlying water was calculated, and the release risk of phosphorus in sediment sediment was analyzed. The results showed that (1) in wetland, the pollution load of various forms of phosphorus existed along the downward trend of.1) surface water. The concentration of phosphorus (SRP) decreased by 80%. The phosphorus pollution load was reduced by 80% in the clear water area, 94% in the reed community, 91% in the cattail community and the SRP removal effect in the aquatic vegetation. In the middle reaches, the phosphorus form in the surface water body was mainly particulate phosphorus (PP), and the percentage of PP in the plant community was lower than that in the clear water area. The maximum physical and chemical properties of various forms of phosphorus are the decrease of SRP concentration along the acidity and alkalinity (pH) and dissolved oxygen (DO).2. The phosphorus pollution load is reduced by 91% in the reed community and 94% in the cattail community, and the reduction is higher than that in the clear water region (81%); the percentage of PP is lower at the entrance and then in the middle reaches. The most important physical and chemical properties are pH.3). In most sections along the path, the concentration of phosphorus in the interstitial water is higher than that of the plant community in the clear water area, and the interstitial water is mainly SRP, and the most important physical and chemical properties of the total phosphorus (TP) 46%~91%. are pH and conductivity (C).4 at the entrance of the wetland, and the sediment of the clear water region is TP containing. The amount of TP was higher than that of the reed community and cattail community in the same section. The content of sediment in the sediments of the plant community was still at a high level, while the content of the sediment in the plant community was still at a high level. The content of organic matter was significantly positively correlated with the content of TP in the sediments. The activity of alkaline phosphatase and the content of organophosphorus were significantly negative in the water outlet of the wetland. The content of the sediment was significantly negative. The content of the organic matter and the content of the sediment were significantly negative. The content of the organic matter and the content of the sediments were significantly positive. The activity of alkaline phosphatase and the content of organic phosphorus were significantly negative. Correlation.5) Reed was high in L1 cross-section height, but phosphorus absorption was not high, but at X3 section, the stem of cattail was the smallest (20.18 cm), and phosphorus content in the body was as high as 2.74g/kg. (2) clear water area and plant community with different vertical migration and transformation mechanism.1), the vertical section of reed community and cattail community, TP, TDP, SRP were mainly distributed in the vertical section. The.TP, TDP, SRP in the overlying water and interstitial water are mainly in the overlying water of the plant community, the proportion of interstitial water is lower.2), the phosphorus is mainly concentrated in the sediments, the proportion of the water in the water body and the sediment is more than 95%, the next is the plant, the lowest is the water body.3) and the interstitial water in the clear water area of the sediments is NaO and the sediment NaO H-P has a significant correlation; the surface water and overlying water body of the reed community have significant correlation with the organic phosphorus in the sediment; the surface water and overlying water of the cattail community, the overlying water and the interstitial water have a significant correlation of.4). The phosphorus in the wetland is diffused from the sediments to the overlying water. The surface sediment adsorption index (PSI) of the wetland surface is in the wetland. The distribution of low posterior segment height in the front segment shows that the maximum phosphorus adsorption of the sediments in the front of the wetland is relatively small. The adsorption saturation (DPS) of the surface sediments in the plant community is higher than that in the clear water area, and the PSI is lower than that in the clear water area, indicating that the phosphorus in the surface sediments of the plant community is easier to enter the overlying water. The phosphorus release risk index (ERI) is used. The potential release risk of phosphorus in the surface sediments of the wetland was evaluated. The results showed that the risk of phosphorus release in the surface sediments of the wetland was at a high risk, and the phosphorus release risk was the highest in the cattail community. In the restoration wetland, the phosphorus was spread from the sediments to the overlying water body and had a high risk of phosphorus release. The concentration of phosphorus and the accumulation of phosphorus in the sediments are lower than those in the clear water area. The plant can reduce the phosphorus pollution load in the region. This study further understands and evaluated the purification function of the water quality of the wetland, which provides the scientific basis for the scientific planning of the restoration of the ecological engineering of the wetland sewage treatment.

【学位授予单位】：华北电力大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X52

【参考文献】