高浊度原水磁加载混凝应急饮用水处理试验研究及工艺设计

发布时间：2018-08-02 10:51

【摘要】：当地震、泥石流、山洪等突发性自然灾害发生时,强降雨对松散的物质源产生强烈的冲刷作用,导致水体浊度在极短时间内大幅度升高,从而使饮用水源地受到严重污染,居民的饮用水安全受到严重威胁。高浊度水处理最有效的方法是化学混凝沉淀法,但传统混凝沉淀技术无法满足应急水处理的要求。磁加载混凝技术具有处理能力大、效率高、出水水质安全可靠等优势,在应急饮用水处理领域拥有广阔的应用前景。本文在对突发性自然灾害水源地水质调研分析基础上,拟通过磁加载混凝小试及中试试验研究,考察混凝剂、助凝剂及磁粉投加量等因素对浊度去除率的影响,并开发一套移动式磁加载混凝应急水处理设备,为磁加载混凝设备的工程化设计提供理论依据。具体研究成果如下:(1)对地震、洪涝、台风等典型突发性自然灾害情况下水源地水质进行调研分析。分析结果表明,自然灾害情况下的水流湍急、降水明显,会将大量地面的颗粒污染物裹挟带入水中,浊度急剧升高,可达200～500 NTU以上,是突发性自然灾害中最主要的污染指标。(2)常规混凝沉淀和磁加载混凝沉淀对比小试试验研究。考察了混凝剂、助凝剂以及磁粉投加量对浊度去除效率的影响,研究结果表明,磁加载混凝工艺对高浊度水处理效果最好,当原水浊度在200 NTU以下时,磁加载混凝反应聚合氯化铝(PAC)、聚丙烯酰胺(PAM)和磁粉最佳投加量分别为10 mg/L、0.2 mg/L和75 mg/L,磁粉最佳粒径为500目,浊度去除率大于97%,出水浊度小于3 NTU,PAC的投加量与常规混凝相比减少50%以上;当原水浊度在200～500 NTU时,磁粉最佳投加量提高到为150 mg/L。通过测定反应体系的Zeta电位、观察絮体结构特征初步探究了磁粉影响混凝反应的机理,磁粉可以通过降低混凝反应体系中的Zeta电位促进混凝反应的进行,磁加载混凝形成的磁絮体结构紧密,沉降速率是常规絮体的16倍。(3)设计5m3/h磁加载混凝沉淀中试装置并进行中试试验研究。研究结果表明,磁加载混凝在沉淀池表面负荷10 m3/(m2·h),原水浊度在0～100 NTU、100～200NTU、200～500NTU三种范围时,出水浊度均小于3 NTU,去除率分别达到95%、98%、99.4%,出水浊度达到《生活饮用水卫生标准》(GB5749-2006)(水源受限制条件下浊度限值)。磁粉分离回收系统选择磁力旋流分离技术,当控制电压为36V、电源脉动控制器的工作方式为开10s断1 s时磁力旋流装置分离回收磁粉效率最高,可达93%左右。(4)移动式磁加载混凝应急水处理系统方案的初步设计。在试验室小试及中试试验确定的磁加载混凝工艺参数基础上,结合工程实际情况,完成了 360 m3/d移动式磁加载混凝应急水处理系统方案的初步设计,设备具有体积小、重量轻的特点,适用于高浊度原水的应急饮用水处理。本研究为磁加载混凝应急饮用水设备设计及工程实践提供了一定的参考和设计依据。
[Abstract]:When sudden natural disasters such as earthquakes, debris flows and flash floods occur, strong rainfall has a strong scouring effect on loose material sources, resulting in a large increase in water turbidity in a very short period of time, thus causing serious pollution to the drinking water sources. The safety of drinking water for the population is seriously threatened. Chemical coagulation precipitation is the most effective method for high turbidity water treatment, but the traditional coagulation sedimentation technology can not meet the requirements of emergency water treatment. Magnetic loading coagulation technology has the advantages of large treatment capacity, high efficiency, safe and reliable effluent quality, and has a broad application prospect in the field of emergency drinking water treatment. Based on the investigation and analysis of the water quality in the source area of sudden natural disasters, this paper intends to investigate the effect of coagulant, coagulant and magnetic powder on turbidity removal rate by magnetic loading coagulation test and pilot test. A set of mobile magnetic loading coagulation emergency water treatment equipment is developed to provide theoretical basis for the engineering design of magnetic loading coagulation equipment. The specific research results are as follows: (1) the water quality of water source under typical sudden natural disasters, such as earthquakes, floods, typhoons and so on, is investigated and analyzed. The results show that under natural disasters, the flow of water is swift and the precipitation is obvious, and a large number of surface particulate pollutants will be carried into the water, and the turbidity will rise sharply, reaching more than 200 ~ 500 NTU. It is the most important pollution index in sudden natural disasters. (2) A comparative experimental study of conventional coagulation precipitation and magnetic loading coagulation precipitation. The effects of coagulant, coagulant aid and magnetic powder on turbidity removal efficiency were investigated. The results showed that magnetic loading coagulation process had the best effect on the treatment of high turbidity water, when the turbidity of raw water was below 200 NTU. The optimum dosages of poly-aluminum chloride (PAC), polyacrylamide (PAM) and magnetic powder were 10 mg / L, 0.2 mg/L and 75 mg / L, respectively, and the optimum particle size of magnetic powder was 500 mesh. The turbidity removal rate is greater than 97 and the dosage of effluent turbidity is less than 3 NTU PAC by more than 50% compared with conventional coagulation, and when the turbidity of raw water is 200 ~ 500 NTU, the optimum dosage of magnetic powder is increased to 150 mg / L. By measuring the Zeta potential of the reaction system and observing the structural characteristics of the flocs, the mechanism of the effect of magnetic powder on the coagulation reaction was preliminarily explored. The magnetic powder could promote the coagulation reaction by reducing the Zeta potential in the coagulation reaction system. The structure of magnetic flocs formed by magnetic loading coagulation is close, and the settling rate is 16 times that of conventional flocs. (3) the pilot-scale test device of 5m3/h magnetically loaded coagulation and sedimentation is designed and studied in pilot-scale tests. The results show that when the surface load of the sedimentation tank is 10 m3 / (m ~ 2 h), the turbidity of the raw water is in the range of 0 ~ 100 NTU ~ (100) ~ (100) NTU ~ (200) NT ~ (200) ~ (500) NTU. The turbidity of the effluent was less than 3 NTU, and the removal rate was 95 ~ 98 ~ 99.4, respectively. The turbidity of the effluent reached GB5749-2006 (turbidity limit under the limited water source condition). The magnetic particle separation and recovery system selects the magnetic swirl separation technology. When the control voltage is 36V and the mode of the power pulsation controller is on 10s and 1s, the magnetic particle separation and recovery efficiency of the magnetic swirl device is the highest. It can reach about 93%. (4) preliminary design of mobile magnetic loading coagulation emergency water treatment system. On the basis of the technical parameters of magnetic loading coagulation determined in laboratory and pilot test, the preliminary design of 360m 3 / d mobile magnetic loading coagulation emergency water treatment system has been completed in combination with the actual engineering conditions. The equipment has a small size. Light weight features, suitable for high turbidity raw water emergency drinking water treatment. This study provides a reference and design basis for the design and engineering practice of magnetic loading coagulation emergency drinking water equipment.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU991.2

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