海水淡化预处理技术研究

发布时间：2018-04-21 04:01

本文选题：海水淡化 + 预处理　；参考：《天津大学》2015年硕士论文

【摘要】：随着经济的发展和社会的进步,人类对水资源的需求量越来越大,再加上对水资源的不合理开采和利用,很多国家和地区出现不同程度的缺水问题,水资源短缺成为仅次于全球气候变暖的世界第二大环境问题。因此,合理开发利用海洋资源,发展海水淡化事业将势在必行。近年来,蒸馏法和反渗透法作为海水淡化的主要方法得到了广泛应用,然而,海水水质的差异要求海水在进入蒸发装置和反渗透膜之前要进行必要的预处理。因此,开展反渗透海水淡化(SWRO)和蒸馏法海水淡化的预处理工艺研究,改善海水淡化装置的进水水质,减轻蒸馏法海水淡化设备的腐蚀,减缓反渗透膜的污染,对促进海水淡化的产业化进程具有重大意义。课题对浸没式超滤处理海水的工艺进行研究,结果表明,直接超滤和混凝/超滤工艺超滤产水SDI15小于2.0,浊度小于0.2NTU;当超滤前设置混凝装置后,在适宜的絮凝剂投加量下,超滤进水的颗粒物数目减少。与直接超滤工艺相比,超滤膜比通量反洗恢复率提高,过滤后膜表面滤饼层变得疏松多孔,超滤膜比通量衰减速度减缓,膜孔孔径偏移减小。表明了混凝/超滤作为反渗透海水淡化预处理工艺时,产水满足反渗透的进水要求,超滤膜本身污染减轻,反洗恢复率提高。另外,实验又对外压式超滤处理海水的工艺进行探讨,并着重考察超滤的产水水质、跨膜压差变化、过滤通量选择、错流流量对跨膜压差的影响及跨膜压差反洗恢复率的变化。本文针对重金属离子对蒸馏法中采用铝合金作为换热材料的海水淡化装置的腐蚀现象,进行填充有铝合金填料的离子陷阱装置去除海水中Fe3+的实验研究,利用动电位极化电化学测试进行铝合金材料的筛选。加工有效比表面积较大的θ环填料,并将其填充在离子陷阱装置中进行海水流速、初始Fe3+浓度、盐度、pH等不同操作条件对海水中Fe3+去除的影响研究,实验结果表明,离子陷阱装置对海水中Fe3+的去除率可达到95%以上。实验设计加工填充有700Y波纹板整装填料的离子陷阱中试装置,并进行现场试验验证。
[Abstract]:With the development of the economy and the progress of the society, the demand for water resources is becoming more and more large. In addition, the unreasonable exploitation and utilization of water resources, many countries and regions have different degrees of water shortage. The shortage of water resources has become the second world environmental problem second only to the global climate warming. Therefore, the rational exploitation and utilization of the ocean is made. Resources, the development of seawater desalination will be imperative. In recent years, the distillation and reverse osmosis methods have been widely used as the main methods of seawater desalination. However, the difference of water quality in seawater requires the necessary pretreatment of seawater before entering the evaporator and the reverse osmosis membrane. Therefore, the reverse osmosis seawater desalination (SWRO) and distillation method is carried out. Study on pretreatment technology of seawater desalination, improving water quality of seawater desalination plant, reducing the corrosion of desalination equipment and slowing down the pollution of reverse osmosis membrane, is of great significance to promoting the industrialization process of seawater desalination. The ultrafiltration process is less than 2 and the turbidity is less than 2 and the turbidity is less than 0.2NTU. When the coagulation device is set before ultrafiltration, the number of particles in the ultrafiltration is reduced. Compared with the direct ultrafiltration process, the recovery rate of the ultrafiltration membrane is higher than that of the flux, the filter cake layer becomes porous and the ultrafiltration membrane decreases. When the coagulation / ultrafiltration is used as the pre treatment process for reverse osmosis seawater desalination, the water production meets the requirement of the reverse osmosis, the pollution of the ultrafiltration membrane is reduced and the recovery rate of the reverse washing is improved. In addition, the experiment is also discussed in the experiment of the treatment of seawater with external pressure ultrafiltration, and the water producing water of ultrafiltration is investigated. Quality, transmembrane pressure difference, filtration flux selection, the influence of flow rate on cross membrane pressure difference and the change of backwash recovery rate of transmembrane pressure difference. In this paper, the ion trap device filled with aluminum alloy filler is used to remove Fe3 in seawater by heavy metal ions on the corrosion phenomenon of aluminum alloy as heat exchanger in the distillation process. The experimental study of + is used to screen the aluminum alloy materials by electrodynamic polarization electrochemical testing. The effect of different operating conditions on the seawater flow rate, initial Fe3+ concentration, salinity, pH and other operating conditions on the Fe3+ removal in the sea water is studied. The removal rate of Fe3+ in sea water can be over 95% in the trap device. The experimental design and processing is filled with the pilot device of the ion trap in the packing of the 700Y corrugated plate, and the field test is carried out.

【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P747

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