微曝气强化生态浮床对污水中COD的去除效果研究

发布时间：2018-03-29 10:10

本文选题：生态浮床　切入点：COD_(Cr)　出处：《西南交通大学》2015年硕士论文

【摘要】：防治水体污染,保护和改善水体环境,保障饮用水安全,对促进经济社会全面协调可持续发展和实现“中国梦”具有重要意义。有机污染物是衡量水环境污染程度和国家控制削减的重要指标。水体中有机污染物过高时表现为水体发黑、发臭、破坏水体平衡,不仅危害水体生态系统,还能通过食物链进入顶端,危害人类健康。因此,控制和削减有机污染物是治理水体环境的重要目标之一。生态浮床作为一种有效的生物-生态原位修复工程技术,利用植物吸收和根系微生物作用,以人工浮床的形式固定高等水生植物到污染水体中,以达到削减有机物和氮磷、净化水质的目的。具有可造作性强、成本低、易维护、景观效果好、二次污染小等优点,近年来已在水库、湖泊等治理中取得了较为显著的效果。本论文在传统生态浮床的基础上,通过引进微曝气系统和人工介质,构建“曝气单元(微孔曝气系统)+微生物处理单元(人工介质)+水生植物单元(紫鸢尾植物浮床)”的微曝气强化生态浮床,探讨分析该浮床在不同运行条件下,对水中有机物去除效果研究,了解微曝气强化生态浮床系统中有机物的变化规律和去除机理,确定最佳运行条件,为微曝气强化生态浮床技术的水体污染防治控制理论和实际工程应用应用提供理论依据和设计支撑,并得出如下主要结论：(1)在相同实验条件下,微曝气强化生态浮床中C ODcr、TN禾口TP的去除率分别59.2%、76.8%、和62.7%,高于强化生态浮床和传统生态浮CODcr、TN和TP的去除率。结果表明采用微孔曝气、人工介质、紫鸢尾植物浮床构成的微曝气强化生态浮床能显著提高水中微生物的生物量和生物活性,人工介质和曝气单元的引入强化了浮床系统对水中有机负荷的去除效率和脱氮除磷的效果。同时,紫鸢尾可作为一种良好的浮床植物。(2)在相同实验条件下,不同曝气量的微曝气强化生态浮床去除BOD5和CODcr的效率表现为：7.5Lmin-110Lmin-15Lmin-12.5Lmin-10Lmin-1。水体中DO值和微生物量是影响生态浮床去除CODcr和BOD5效果的重要因素。过高的曝气量对提高水体中有机物的去除效率并不明显,因此,综合考虑效率及成本,应合理设计曝气量。(3)不同人工介质对微曝气强化生态浮床去除水中有机物的效果不同,其对BOD5和CODcr的去除效率表现为：组合填料组合+立体填料立体弹性填料。相比立体弹性填料放射状结构,组合填料的涤纶纤维结构更有利于截留水中有机物和适合微生物生长,单纯提高填料表面积并不能有效提高填料的水质净化运行效果,需要综合考虑填料材质、截留水中有机物和易于微生物附着生长等因素。(4)不同曝气量、不同人工介质条件下微曝气强化生态浮床BOD5/CODcr比值随时间呈现两边高、中间低、后期比初期低的走势。微曝气强化生态浮床处理后的污染水体中B/C值有所下降。
[Abstract]:To prevent and control water pollution, to protect and improve the water environment, and to ensure the safety of drinking water, It is of great significance to promote the overall coordinated and sustainable development of economy and society and to realize "Chinese Dream". Organic pollutants are an important index to measure the pollution degree of water environment and to be controlled and reduced by the state. When the organic pollutants in water body are too high, the organic pollutants in water are too high. It is manifested in the blackening of the water body, Smelling, disrupting water balance, not only endangering the aquatic ecosystem, but also reaching the top through the food chain, endangering human health. The control and reduction of organic pollutants is one of the important objectives of water environment control. As an effective in situ biological-ecological remediation technology, ecological floating bed utilizes plant absorption and root microorganism. In order to reduce organic matter and nitrogen and phosphorus and purify water quality, high aquatic plants were fixed in the form of artificial floating bed. It has the advantages of strong craftability, low cost, easy maintenance, good landscape effect and little secondary pollution, etc. In recent years, more remarkable results have been obtained in the treatment of reservoirs and lakes. Based on the traditional ecological floating bed, the microaeration system and artificial medium are introduced in this paper. The micro-aeration enhanced ecological floating bed of "microorganism treatment unit (artificial medium) aquatic plant unit (purple iris floatation bed)" was constructed, and the floating bed was analyzed under different operating conditions. In this paper, the removal effect of organic matter in water was studied, and the change law and removal mechanism of organic matter in micro-aeration enhanced ecological floating bed system were understood, and the optimum operating conditions were determined. It provides theoretical basis and design support for water pollution prevention and control theory and practical engineering application of micro-aeration enhanced ecological floating bed technology, and draws the following main conclusions: 1) under the same experimental conditions, The removal rates of TP in the inlet of C ODcrcrTN in the ecological floating bed enhanced by micro-aeration were 59.2 and 62.7, respectively, which were higher than those in the enhanced ecological floatation bed and the traditional ecological floating bed. The results showed that microporous aeration and artificial medium were used in the removal of TN and TP. The micro-aeration enhanced ecological floating bed can significantly improve the biomass and biological activity of microorganisms in water. The introduction of artificial medium and aeration unit strengthened the removal efficiency of organic load and nitrogen and phosphorus removal in water by floating bed system. At the same time, Iris purpurea could be used as a good floating bed plant. The removal efficiency of BOD5 and CODcr by micro-aeration enhanced ecological floating bed with different aeration rates is as follows: 7.5Lmin-110Lmin-15Lmin-12.5 Lmin-10Lmin-1. Do and microbial biomass in water are important factors affecting the removal of CODcr and BOD5 by ecological floating bed. The removal efficiency is not obvious. Therefore, considering the efficiency and cost, the aeration volume should be reasonably designed. 3) the effect of different artificial media on the removal of organic matter in water by micro-aeration enhanced ecological floating bed is different. The removal efficiency of BOD5 and CODcr is as follows: combined packing and stereoscopic elastic packing. Compared with the radial structure of stereoscopic elastic packing, the structure of polyester fiber with combined packing is more favorable for intercepting organic matter in water and suitable for microbial growth. Simply increasing the surface area of fillers can not effectively improve the performance of water quality purification of fillers. It is necessary to consider comprehensively the factors such as packing material, interception of organic matter in water and easy growth of microorganism, etc.) different aeration rates should be taken into account. The BOD5/CODcr ratio of micro-aeration enhanced ecological floating bed in different artificial medium showed the trend of high on both sides, low in the middle, and lower in the later period than in the early stage. The B / C value of polluted water decreased after micro-aeration enhanced ecological floating bed treatment.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703

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