城市硬质化可道水体复氧技术研究

发布时间：2018-02-09 03:57

本文关键词： 硬质化河道水生植物光合作用微孔曝气技术水力跌水复氧技术协同复氧技术　出处：《郑州大学》2015年硕士论文　论文类型：学位论文

【摘要】：城市硬质化河道存在水体自净能力弱、耗氧有机污染物浓度高、水体黑臭等问题,这些问题与水体缺氧密切相关,针对这些问题,本文通过研究水生植物光合作用、微孔曝气技术、水力跌水三种复氧技术的影响因素、复氧效果及对硬质化河道水体中污染物的去除效果,合理安排微孔曝气、水力跌水、水生植物光合作用三种复氧技术的不同布设方式,提出微孔曝气/水力跌水/水生植物光合作用协同复氧技术。在此基础上,通过比较微孔曝气/水力跌水/水生植物光合作用协同复氧技术不同布设方式的经济性,为硬质化河道水体复氧技术在实际工程中不同条件下采用的布设方式提出建议,为硬质化河道的水污染净化提供技术支持。本文的主要结论有:(1)四种本土沉水植物轮叶黑藻、金鱼藻、苦草、狐尾藻在自然光照条件下通过光合作用对水体具有复氧效果,对水体的复氧效果顺序依次为轮叶黑藻苦草金鱼藻狐尾藻;轮叶黑藻、金鱼藻、苦草、狐尾藻对水体氨氮具有较好去除率,轮叶黑藻去除水体氨氮效果最好;这四种水生植物对水体COD的去除效果不明显,水生植物的生长状况影响着水生植物对水体污染物的去除效果。(2)通过微孔曝气复氧实验室对比试验,得出水体中DO含量达到稳定值所需曝气时间与曝气强度呈负相关,与曝气水深呈正相关;曝气点处水体DO均能在4h内达到6mg/L以上;微孔曝气对水体的复氧效果在纵向上不存在分层现象,在横向上对水体复氧效果逐渐递减,对水体COD、氨氮去除效果在纵向上不存在分层现象;微孔曝气对硬质化河道水体中COD、氨氮去除率较低;在水深为0.3m-0.7m范围内,曝气强度为200L/(m2·h)时,微孔曝气在连续运行及间歇曝气(曝气40 min,静止20min,交替进行)运行条件下,能够在3h内将水体DO提升到6mg/L以上,满足复氧目标需求;微孔曝气在最不利水深0.7m条件下间歇运行时,停止曝气后水体DO随时间逐渐降低,降低速率为0.0249mg/(L·min)。(3)不同跌水高度(0.2m、0.4m、0.6m)、跌水流量(50L/h、100L/h、150L/h)、跌水深度(0.2m、0.4m)条件下,经过一级水力跌水复氧后溢流面下游0.25m和溢流面下游0.75m处水体的DO增加量整体较小,缺氧水体经过一级水力跌水复氧后水体中DO不能达到6mg/L的目标,复氧效果不理想,为提高其复氧效果,需考虑设置多级水力跌水。水力跌水措施对硬质化河道水体的复氧效果整体上与跌水高度、跌水流量、跌水深度呈正相关,与进水DO浓度呈负相关。水力跌水复氧措施对氨氮、COD去除效果较差。(4)在微孔曝气、水力跌水、水生植物光合作用复氧效果研究的基础上,得出使水体DO达到6mg/L以上的五种复氧布设方式:微孔曝气复氧技术(方式A)、水力跌水复氧技术(方式B)、水力跌水-微孔曝气-水生植物组合方式(方式C)、微孔曝气-水力跌水-水生植物组合方式(方式D)、水力跌水-水生植物组合方式(方式E)。并从微孔曝气时间长短上比较各种布设方式的经济性,为硬质化河道水体复氧技术在实际工程应用中的运行方式提出建议。
[Abstract]:City hard river water self purification ability are weak, the concentration of oxygen consumption of high organic pollutants, water black odor problems, these problems are closely related to hypoxia and water, in order to solve these problems, this paper research on Photosynthesis of aquatic plants, aeration technology, hydraulic drop three effects of reoxygenation technology factors, the effect of reaeration and removal of hard of pollutants in the river water body, reasonable arrangement of aeration, water drop, the photosynthesis of aquatic plants and three kinds of reoxygenation, different arrangement mode, put forward the micropore aeration / hydraulic water / aquatic plant photosynthesis synergistic reoxygenation. On this basis, through economic comparison of microporous aeration / hydraulic / drop of photosynthesis of aquatic plants co reoxygenation, different arrangement mode, put forward suggestion for hard River reaeration technique used in practical engineering under different conditions, as hard Water pollution matter of river purification to provide technical support. The main conclusions of this paper are: (1) four native submerged plant Hydrilla verticillata, hornwort, Vallisneria, Myriophyllum under natural light conditions through photosynthesis with oxygen effect of water, the water reaeration effect order of Hydrilla Ceratophyllaceae Myriophyllum Vallisneria; Hydrilla verticillata, Ceratophyllum demersum, Vallisneria spiralis, Myriophyllum had a good removal rate of ammonia nitrogen in water, Hydrilla removal ammonia water had the best effect; effect on removing COD in the water of the four kinds of aquatic plants is not obvious, the growth status of aquatic plants affects the removal effect of pollutants of the aquatic plants. (2) by aeration reoxygenation laboratory tests, the content of DO in water reached a stable value required aeration time was negatively correlated with aeration intensity and aeration depth was positively correlated with aeration; point of water DO can reach 6mg in 4H /L; effect of oxygen complex on water aeration does not exist in the vertical stratification, the lateral of reaeration effect decreases gradually, on the water COD, ammonia nitrogen removal does not exist in the vertical stratification; aeration of hard river water COD, ammonia nitrogen removal rate is low; in depth was in the range of 0.3m-0.7m, aeration rate of 200L/ (M2 - H), aeration in the continuous operation and intermittent aeration (aeration 40 min, static 20min, alternating) operating conditions, can be in 3H water DO to more than 6mg/L, to meet the target of oxygen demand; aeration in the most unfavorable water depth 0.7m under the condition of intermittent operation, stop aeration after water DO decreases with time, reduce the rate of 0.0249mg/ (L - min). (3) different waterfall height (0.2m, 0.4m, 0.6m), water flow (50L/h, 100L/h, 150L/h), water depth (0.2m, 0.4m) under the condition of a class hydraulic drop Water after reoxygenation spillway downstream 0.25m and 0.75m downstream of the overflow surface water DO increase the overall small, anoxic water through a water drop after reoxygenation DO in water can not reach the goal of 6mg/L, reoxygenation effect is not ideal, in order to improve the effect of reaeration, should be considered to set up multi-level water drop reaeration. The effect of hydraulic drop measures of river water to hard on the whole and the falling height, water flow, water depth was positively correlated, negatively correlated with the concentration of DO. The hydraulic water drop reaeration measures of ammonia nitrogen, the removal efficiency of COD is poor. (4) in aeration, hydraulic drop, basis of aquatic vegetation photosynthesis reaeration effect research on the water DO 6mg/L reached above five reoxygen layout: microporous aeration technology (A), hydraulic waterfall reoxygenation (B), hydraulic drop - aeration - aquatic plant combinations (C), microporous aeration Gas - hydraulic drop - aquatic plant combination (D), water drop - aquatic plant combinations (E). And the length of time from aeration economic comparison of various layout methods, put forward suggestions for the operation of hard River reaeration technology in the practical application.

【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X52

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