不同盐度、底泥及扰动条件下再生水补水景观水体水质变化

发布时间：2018-05-05 01:05

本文选题：再生水 + 盐度　；参考：《西安建筑科技大学》2017年硕士论文

【摘要】：景观水体富营养化控制一直是景观水体研究的热门领域,景观水体富营养化主要受水体中营养盐浓度的影响很大,同时各种环境因素如光照、水温等都对水体富营养化有着重要的影响。特别是目前很多城市人工景观水体水源采用再生水,使得这部分景观水体更容易发生水体富营养化,开展在不同控制条件下再生水补给景观水体水质变化规律的研究已成为当前景观水体研究的热点问题。通过构建人工水族箱试验装置,对以再生水做为水源的景观水体为研究对象,选取影响景观水体富营养化的水体盐度、垂直方向扰动以及底泥沉积物等几个重要外界因素,考察了不同水体盐度,垂向扰动对水体感官指标、营养盐浓度、藻类生长及藻类种群变化的影响,并通过烧杯试验模拟了不同底泥不同上覆水对底泥中污染物的释放与富集以及上覆水的水质变化的影响。研究结果表明:(1)景观水体在最适盐度(3g/L)条件下,水体中的藻类繁殖速度最快,水体富营养化程度较高;过高的盐度可以显著抑制藻类的生长繁殖,且盐度的改变会引起水中藻类优势种群的变化。盐度通过影响水体中藻类的生长繁殖,进而影响景观水体的水质。(2)低流速扰动条件下(0~4.6m/h),垂向扰动流速越大藻类生长越容易受到抑制。在高扰动强度下(7.5~30m/h),22.5m/h试验组对水体中藻类生长的影响抑制最为显著,大于或小于该扰动强度时均会促进藻类的生长繁殖。相比于垂直扰动试验组,推流试验组叶绿素a浓度增长较快,表明垂直方向扰动更能有效抑制藻类生长。且流速的变化能够导致水体中藻类优势种群的变化。(3)上覆水与沉积物之间营养元素之间的污染物质交换是一个动态平衡的关系,底泥存在吸附-释放临界浓度,上覆水中营养元素浓度高则表现为在底泥中累积。扰动是影响营养物释放的重要因素,扰动使吸附-释放临界浓度提高且加速了底泥中的营养物的释放。沣河沉积物中氮的吸附-释放临界浓度为0.7~1.09mg/L,有扰(4)动时上升为0.8~1.32mg/L,磷的吸附-释放临界浓度在0.07~0.08mg/L之间,有扰动时上升为0.08~0.12mg/L。思源湖沉积物中氮的吸附-释放临界浓度为.57~3.24mg/L,有扰动时为2.23~4.34mg/L。磷的吸附-释放临界浓度在0.36~0.53mg/L之间,有扰动时上升为0.40~0.82mg/L。
[Abstract]:Eutrophication control of landscape water is always a hot field in landscape water research. Eutrophication of landscape water is mainly affected by nutrient concentration in water body and various environmental factors such as illumination. Water temperature has an important effect on water eutrophication. In particular, at present, many urban artificial landscape water sources use recycled water, which makes this part of the landscape water more prone to eutrophication. It has become a hot issue to study the changing law of water quality of reclaimed water in landscape water body under different control conditions. By constructing an artificial aquarium test device, several important external factors, such as salinity, vertical disturbance and sediment, which affect eutrophication of landscape water body, are selected for landscape water body with reclaimed water as its water source. The effects of salinity and vertical disturbance on sensory index, nutrient concentration, algae growth and algae population were investigated. The effects of different overlying water on the release and enrichment of pollutants and the change of water quality of overlying water were simulated by beaker test. The results showed that under the optimum salinity of 3 g / L, the algae propagation rate in the landscape water was the fastest and the eutrophication degree of the water was higher, and too high salinity could significantly inhibit the growth and reproduction of algae. And the change of salinity will lead to the change of dominant population of algae in water. Salinity affects the growth and reproduction of algae in water, and then affects the water quality of landscape water. (2) under the condition of low velocity disturbance, algae growth is easily inhibited with the increase of vertical disturbance velocity. Under the high disturbance intensity, the effect of 7.5m / h 30 m / h and 22.5m / h on algae growth in water was the most significant. When the disturbance intensity was greater than or less than the disturbance intensity, the algae growth and reproduction would be promoted. Compared with the vertical disturbance test group, the chlorophyll a concentration increased faster in the push flow test group, which indicated that the vertical disturbance could inhibit algae growth more effectively. And the change of velocity can lead to the change of dominant algal population in water body. The pollution material exchange between overlying water and sediment is a dynamic equilibrium relationship, and there is a critical concentration of adsorption-release in sediment. The high concentration of nutrient elements in the overlying water is the accumulation of nutrients in the sediment. Disturbance is an important factor affecting nutrient release. Disturbance increases the critical concentration of adsorption-release and accelerates the release of nutrients from sediment. The critical concentration of nitrogen adsorption-release in sediment is 0.7 ~ 1.09 mg / L, with disturbance 4). The critical concentration of adsorption-release of phosphorus is between 0.07~0.08mg/L and 0.08 ~ 0.12 mg 路L ~ (-1) 路L ~ (-1) ~ (-1) ~ (-1) mg 路L ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1) 路L ~ (-1) ~ (-1) ~ (-1) ~ (-1). The critical concentration of nitrogen adsorption-release in Siyuan Lake sediments is. 57 ~ 3.24 mg / L, and 2.23 ~ 4.34 mg / L when disturbed. The critical concentration of phosphorus adsorption-release is between 0.36~0.53mg/L and increases to 0.400.82 mg / L when disturbed.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X52

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