原位修复技术抑制城市河道污染底泥氮磷释放

发布时间：2018-03-06 13:10

本文选题：城市河道　切入点：氮磷　出处：《安徽理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：城市河道是一个城市的标志之一,它们不仅仅具有供应水源、提供绿地、保护环境和开展旅游等生态功能,也是市民创造文体娱乐与亲近自然的空间。随着城市人口基数的不断膨胀,工业化进程不断加快,大量的生活污水排入河道,水体污染严重,其主要污染物是氮和磷。河道治理是一项复杂的工程,传统的河道修复技术多以底泥疏浚、清水冲淤等异位修复方式为主,这些技术工程周期长、成本高,而且对河道生态系统破坏大,二次污染严重。为了避免传统技术存在的缺陷,本文在前人研究的基础上,利用人工模拟污染河道装置,开展城市河道底泥修复工作的研究,其内容主要包括以下几点:(1)对嘉兴市内16条不同污染水质的河道进行定期取样检测,构建部分河道上覆水体和底泥中主要污染物指标数据库,为后期河道底泥修复工作提供理论支撑。(2)研究污染河道水体和底泥中各污染物浓度季节性变化规律及各指标间相关性,挖掘超标污染物之间隐藏的内含关系。(3)基于以废弃砖块为主的组合覆盖材料开展不同覆盖厚度的原位覆盖技术对污染底泥修复效果研究。(4)基于以金鱼藻、苦草等沉水植物为优势植物群种开展不同种植密度的原位植物修复技术对污染底泥生态修复效果研究。通过以上研究,结果表明:(1)水体和底泥中污染物浓度变化呈现明显的季节性特,而且各污染物间的变化相互影响,具有一定的相关性;(2)原位覆盖修复可有效去除水体和底泥中的氮磷。水体中的TP、TN的净化率分别为85.71%、85.71%,对底泥中TP、TN和NH3-N的净化率分别为83.33%、28.3%、42.4%。覆盖材料的铺设厚度与抑制氮磷释放作用大小成正比,铺设厚度越大,抑制氮磷释放的效果越显著。本次实验已铺设5cm覆盖材料的修复效果最好;(3)以金鱼藻、苦草为材料的原位植物修复技术对水体中TN、TP和NH3-N的净化率分别为74.62%、85.95%、87.5%,水生植物种植密度过大或过小都不利于对氮磷的去除,合理的种植密度既可以有效降解氮磷浓度,也可以实现资源利用最大化。相比传统的异位修复技术,原位修复技术对河体生态系统破坏性更小、成本更低、净化氮磷效率更快。通过此次对原位修复技术的研究,可以为后期城市河道治理和方案制定提供理论依据。
[Abstract]:Urban watercourses are one of the symbols of a city. They have not only the ecological functions of supplying water, providing green space, protecting the environment and developing tourism. It is also a space for citizens to create recreation and to be close to nature. With the continuous expansion of the urban population base and the accelerating process of industrialization, a large amount of domestic sewage is discharged into the river, resulting in serious water pollution. The main pollutants are nitrogen and phosphorus. River management is a complex project. The traditional river restoration technology is mainly composed of sediment dredging, clear water scouring and silting and other ectopic restoration methods. These technologies have a long period of time and high cost. In order to avoid the defects of the traditional technology, this paper, based on the previous research, uses artificial simulation to pollute the river channel device, and carry out the research on the restoration of urban river channel sediment, in order to avoid the defects of the traditional technology. The contents mainly include the following points: 1) sampling and testing regularly on 16 river channels with different polluted water quality in Jiaxing City, and constructing a database of main pollutant indexes in the overlying water and sediment of some river courses. To provide theoretical support for the restoration of river sediment in the late stage.) to study the seasonal variation of pollutant concentration in polluted river water and sediment and the correlation between each index. Research on the effect of In-situ covering Technology with different thickness on the remediation effect of contaminated sediment based on the combination of waste bricks and Brick, based on goldfish algae. Studies on the effects of in-situ phytoremediation techniques with different planting densities on the ecological restoration of polluted sediment were carried out by submerged plants such as Acanthopsis chinensis as dominant plant species. The results show that the variation of pollutant concentration in water and sediment is seasonal, and the change of pollutants affects each other. In situ coverage and restoration can effectively remove nitrogen and phosphorus from water and sediment. The purification rate of TPN TN in water is 85.71and the purification rate of NH3-N is 83.3328.3% 42.4.The laying thickness and inhibition of the covering material are 85.71and 85.71respectively. The effect of nitrogen and phosphorus release is proportional to that of nitrogen and phosphorus. The greater the laying thickness, the more significant the inhibition effect of nitrogen and phosphorus release. The in situ phytoremediation rate of TNF- TP and NH3-N in water was 74.62 and 85.95%, respectively. The high or too small planting density of aquatic plants was not conducive to the removal of nitrogen and phosphorus, and the reasonable planting density could effectively degrade the nitrogen and phosphorus concentration. It can also maximize the utilization of resources. Compared with the traditional ectopic restoration technology, in situ restoration technology is less destructive to the river ecosystem, lower cost, and faster to purify nitrogen and phosphorus. It can provide theoretical basis for urban river regulation and scheme formulation in the later period.
【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X52

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