建筑泥浆高效综合脱水技术研究

发布时间：2018-01-14 14:03

本文关键词：建筑泥浆高效综合脱水技术研究　出处：《东南大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着城市建筑日趋密集化,建筑泥浆量越来越大,其处理处置问题已逐渐成为经济社会发展中的突出问题。本课题根据南京现场桩基泥浆的实际情况,通过实验室试验,研究了建筑泥浆高效快速脱水技术。利用数据处理软件对试验结果进行处理分析,得出了建筑泥浆脱水性能影响因素与其脱水效果之间的关系,为实际工程应用提供必要的理论基础和技术支持。本文主要成果如下：(1)全面研究了建筑泥浆性质。利用Prodigy全谱直读ICP发射光谱仪—高色散大阵列固态检测器、硅酸盐化学成分快速分析测得建筑泥浆以无机物为主；借助Mastersize 2000激光衍射粒度分析仪湿法分析,泥浆由粘土、粉砂及砂组成,其中粘土含量为35%左右,打桩深度越深,出来的泥浆的含砂量越大；用pH计测得建筑泥浆的pH约为9.93。采用对比试验法研究了泥浆性质对其絮凝脱水性能影响,结果显示：含粘土量越大,含固量越高,所需絮凝剂量越大,同时添加絮凝剂能够去除10%左右自然沉淀无法去除的细小颗粒。(2)采用对比试验法及均匀试验法,确定了最佳絮凝剂、最佳分子量、浓度及投加量,研究了最佳絮凝剂的性质及水力条件对泥浆絮凝脱水性能的影响,同时采用扫描电子显微镜研究了最佳絮凝剂的脱水机理。试验结果显示：阴离子型聚丙烯酰胺(APAM)絮凝脱水效果最佳,分子量在1400万～1600万,每250mL泥浆投加25mL-27mL APAM溶液,浓度为0.25%～0.27%时,效果较佳；未处理的泥浆结构疏松,加入APAM后絮体结构变得较为密实紧凑,且有明显的固体大颗粒出现,APAM的絮凝机理以吸附架桥作用为主：分子量、浓度、溶解水质及长时间放置对APAM溶液粘度及絮凝效果影响较大；常温范围内温度的变化对APAM溶液粘度及絮凝效果影响不明显：稳定剂甘油(丙三醇)、乙二醇及尿素对APAM溶液具有良好的稳定效果；长时间放置后,APAM分子上部分酰胺基会发生反应,并造成了其结构的变化；搅拌速度随絮体尺寸增大而逐渐减小,搅拌时间控制在2min左右。(3)研究了重力自然沉降、离心脱水、滤袋脱水对泥浆分离效果的影响,确定了合适的固液分离设备。机械脱水效率高,但能耗大。滤袋脱水效果好,安全且节能。(4)对建筑泥浆上清液进行水质指标测定,在APAM最佳分子量、浓度及添加量范围内,COD、TP、NH3-N均能达到《城镇污水处理厂污染物排放标准》一级A标准,TN、SS能满足一级B标准,清液pH符合规范要求,重金属及无机非金属有害物含量均小于最高允许排放浓度,可以直接排放。
[Abstract]:With the increasing density of urban buildings and the increasing amount of building mud, the treatment and disposal of the mud has gradually become a prominent problem in the economic and social development. This subject is based on the actual situation of pile foundation mud in Nanjing. In this paper, the efficient and rapid dehydration technology of building mud is studied by laboratory test, and the data processing software is used to process and analyze the test results. The relationship between the factors affecting the dehydration performance of building mud and its dehydration effect is obtained. To provide the necessary theoretical basis and technical support for practical engineering application. The main results of this paper are as follows: 1). In this paper, the properties of building mud were studied. The Prodigy full-spectrum direct reading ICP emission spectrometer, high dispersive large array solid-state detector, was used. The rapid analysis of silicate chemical composition shows that the building mud is mainly inorganic. With the help of Mastersize 2000 laser diffraction particle size analyzer, the mud is composed of clay, silt and sand, in which the clay content is about 35%, and the piling depth is deeper. The greater the sand content of the mud out; The pH value of building mud measured by pH was about 9.93. The effect of slurry properties on flocculation and dehydration performance was studied by contrast test. The results showed that the higher the clay content, the higher the solid content. The larger the amount of flocculant is, the better flocculant can be removed by adding flocculant about 10% or so which can not be removed by natural precipitation. The best flocculant is determined by contrast test method and uniform test method. The optimum molecular weight, concentration and dosage were studied. The effects of the optimum flocculant properties and hydraulic conditions on the flocculation and dehydration properties of mud were studied. At the same time, the dewatering mechanism of the best flocculant was studied by scanning electron microscope. The experimental results showed that the flocculation and dehydration effect of anionic polyacrylamide (APAM) was the best. When the molecular weight is 14 million ~ 16 million, 25ml ~ 27ml APAM solution is added per 250ml mud, the effect is better when the concentration is 0.25 ~ 0.27ml. The structure of untreated mud is loose, the flocculation structure becomes more compact after adding APAM, and the flocculation mechanism of APAM is mainly adsorption bridging: molecular weight and concentration. The solution viscosity and flocculation effect of APAM solution were greatly affected by dissolved water quality and long-term storage. The effect of temperature on viscosity and flocculation of APAM solution was not obvious: glycerol (glycerol), ethylene glycol and urea had good stabilization effect on APAM solution. After a long period of storage, some amide groups on the APAM molecule will react and the structure of APAM will change. The effect of natural gravity sedimentation, centrifugal dehydration and filter bag dehydration on slurry separation was studied. The suitable solid-liquid separation equipment is determined. The mechanical dehydration efficiency is high, but the energy consumption is high. The filter bag dehydration effect is good, safety and energy saving. 4) the water quality index of the supernatant of the building mud is determined. In the range of the optimum molecular weight, concentration and addition amount of APAM, the NH3-N of APAM can reach the first class A standard (TN) of pollutant discharge standard of municipal wastewater treatment plant. SS can meet the first B standard, pH of the liquid meets the standard requirements, and the contents of heavy metals and inorganic nonmetallic harmful substances are lower than the maximum allowable emission concentration, and can be discharged directly.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU753.3;X799.1

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