高效反渗透技术处理电厂循环水排污水研究

发布时间：2018-03-26 07:32

本文选题：循环水排污水　切入点：超滤　出处：《北京化工大学》2014年硕士论文

【摘要】：火电厂用水量很大,循环水用量最大占电厂用水总量的70%以上。为了减少补充水量,必须对系统中的水进行脱盐。以往的工艺采用离子交换设备除盐,系统复杂,不易维护,占地面积大,运行使用的酸碱会对环境造成二次污染,运行费用高等缺点。本课题意在为循环水处理提供了一套新的完整、可靠的工业化解决方案,提高循环水回用比例。在国内,高效反渗透技术未进行过处理循环水的中试研究,也从未有项目将此技术用于工程设计。本课题设计了一套高效反渗透工艺,通过石灰软化、脱二氧化碳、超滤和反渗透组成高效反渗透工艺处理循环排污水,并进行了一系列相关实验。另外,本课题以石景山电厂循环排污水处理系统作为一个工程实例进行研究,分析了实际水质和设备运行数据,为将来中试和工程应用提供参考。循环水预处理试验,石灰软化池用于去除循环排污水中的硬度,自清洗盘滤用于滤除废水中的悬浮物和胶体,CO2脱除装置用于去除水中的C02,从而降低碳酸盐硬度。超滤用于去除水中的浊度和悬浮物,并且保证出水中的COD含量满足反渗透装置的进水要求。实验结果表明,废水中的暂时硬度和悬浮物得到了有效地去除,跟循环排污水原水相比CODcr的去除率约为57.4%,浊度去除率约为43%。水中的重碳酸盐和碳酸盐含量大大减少。研究表明,温度和PH值对预处理系统运行有很大影响。合理的超滤反洗周期确定对保护超滤膜和节约能耗也很重要。按照石灰软化池、自清洗盘滤和脱除CO2的预处理工艺处理循环排污水,超滤进水温度调整到30-35℃,超滤产水量为65L/min,反洗周期是45min,在pH调节池将反渗透进水pH调整至8～10,是很合理的运行方法,出水水质能完全满足反渗透的进水要求。反渗透试验,造成反渗透膜结垢的因素主要包括水的硬度和悬浮物含量、水中的SiO2含量,以及废水中的细菌、病毒和其他有机物等。试验研究了SiO2溶解度与温度、pH的关系,计算出了最佳的反渗透运行条件,最大限度地降低反渗透浓水中SiO2造成的膜污堵。结果表明,进水温度在30～35℃,pH值范围为8.5-10,可以有效地提高反渗透水中硅的极限溶解浓度。在阻垢剂投加量的确定试验结果是,阻垢剂加药量推荐为2mg/L,比常规系统投加量大大减少。试验结果,反渗透污堵现象大大改善,脱盐率稳定保持在97%以上,产水回收率达到90%以上,满足火电厂锅炉补给水用水要求。结果证明此工艺可行,并为后续工业化设计提供了数据和参考。由于高效反渗透技术未进行中试研究,未将此技术用于工程设计。本课题以石景山电厂循环排污水处理系统作为一个工程实例进行研究,本系统采用传统UF+RO工艺。研究分析了石景山电厂‘在实行循环排污水利用的新的循环水平衡状况,对系统的装置、水质、运行数据、经济效益进行了详细跟踪观察和研究。掌握了一套完整的预处理系统、超滤系统、反渗透系统运行数据。并与高效反渗透技术进行对比。得出结论,可以实现高效反渗透技术在循环水处理系统的工业化应用。从理论到试验,再到工程实践,本课题为高效反渗透技术应用于循环排污水处理后续工业化设计和应用提供了各种数据和参考。
[Abstract]:Thermal power plant with large amount of water, the maximum amount of circulating water in power plant water accounted for more than 70% of the total. In order to reduce the amount of supplementary water, must carry on the desalination of water in the system. The process of using ion exchange equipment in addition to salt system complex, difficult to maintain, covers an area of large, operation pH can cause two pollution on the environment, higher operation cost disadvantages. This topic provides a new set of complete in the treatment of circulating water, reliable industrial solutions, improve the circulating water reuse ratio. In the domestic, high efficient reverse osmosis technology has not been a pilot Study on the treatment of circulating water in the project will never have the technology for engineering design. This paper designs an efficient reverse osmosis process by lime softening, CO2 removal, ultrafiltration and reverse osmosis, reverse osmosis treatment consisting of circulating sewage process, and conducted a series of experiments. In addition, this topic Taking the wastewater treatment system of Shijingshan power plant as an example, the actual water quality and equipment operation data are analyzed, which will provide references for future pilot and engineering applications.
The test of circulating water pretreatment for the removal of circulating sewage water hardness pool lime softening, self cleaning disc filter for suspended solids and colloidal filter in wastewater, CO2 removal device for the removal of C02, thereby reducing the carbonate hardness. Ultrafiltration for the removal of turbidity and suspended matter, and ensure that the content of COD in the effluent meet the water requirement of reverse osmosis device. The experimental results show that the wastewater in the temporary hardness and suspended solids can be effectively removed, the removal rate of CODcr is about 57.4% compared with the circulating sewage water, the removal rate of turbidity bicarbonate and carbonate content is about 43%. in water is greatly reduced. The results show that the temperature and pH value have great influence for the operation of the system. To determine the pretreatment also is very important to the protection of the ultrafiltration membrane and save energy reasonable ultrafiltration backwashing cycle. According to the lime softening pool, since the pre cleaning disc filter and CO2 removal technology The effluent was adjusted to 30-35 C by ultrafiltration, the water yield of ultrafiltration was 65L/min, the backwash cycle was 45min, and the adjustment of the reverse osmosis water intake pH to pH was adjusted to 8~10, which is a very reasonable operation method. The effluent quality can completely meet the requirements of reverse osmosis water intake.
Reverse osmosis test, resulting in reverse osmosis hardness and suspended solids content in membrane fouling mainly include water, SiO2 content in water and wastewater, bacteria, viruses and other organisms. The experimental study on the solubility of SiO2 and temperature, pH, the anti penetration of the best operating conditions of the calculation, the maximum in order to reduce the reverse osmosis membrane pollution caused by SiO2 concentrated water plugging. The results showed that the water temperature at 30~35 degrees, the pH value is in the range of 8.5-10, can effectively improve the reverse osmosis water. The concentration of dissolved silicon limit in determining the scale inhibitor dosage test result, scale inhibitor dosage recommended for 2mg/L, greatly reduced compared to the conventional dosage system. The test results, the reverse osmosis fouling phenomenon has greatly improved, the desalting rate remained stable at 97% above the water recovery rate reaches above 90%, to meet the requirements of water supply water in the power plant boiler. The results show that this technology is feasible, and for The continued industrial design provides data and reference.
Due to the high efficiency of reverse osmosis technology without pilot study, not the technology for use in engineering design. This paper takes the Shijingshan power plant circulating sewage treatment system as a case study, the traditional UF+RO technology is adopted in this system. Research and analysis of the Shijingshan power plant circulating water balance "in the new implementation of circulating sewage utilization. Device, system of water quality, operation data, carried out a detailed economic observation and research. The pretreatment system, a complete set of ultrafiltration system, reverse osmosis system running data. And compared with the high efficient reverse osmosis technology. The conclusion, can realize high efficient reverse osmosis technology applications in the industrial circulating water system processing.
From theory to experiment, and then to engineering practice, this project provides various data and references for the application of high efficiency reverse osmosis technology in the subsequent industrial design and application of circulating sewage treatment.

【学位授予单位】：北京化工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：X773

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