燃煤电厂脱硫废水处理回用的技术研究

发布时间：2018-06-06 14:43

本文选题：脱硫废水 + 预处理　；参考：《华北电力大学》2017年硕士论文

【摘要】：目前国内大容量燃煤发电机组大多配备湿式烟气脱硫装置,湿法脱硫工艺在对烟气脱硫的同时也会产生大量的脱硫废水。所以研发具有针对性的废水综合回用技术,并对其实际应用效应进行评判是必要的。结合目前脱硫废水回用技术应用现状,在废水水质分析的基础上,进行了预处理、膜浓缩和蒸发结晶实验研究,并采用预处理+石膏晶种法MVR蒸发结晶工艺对脱硫废水进行了现场工程实验研究。通过比对筛选得出:该厂脱硫废水投加氢氧化钙和硫酸钠量依次为13.7g/L、6.0g/L,p H达到12.5,处理后的水质符合石膏晶种法蒸发结晶进水水质要求;DTRO(碟管式反渗透)操作压力较高,在75bar的操作压力下,浓水TDS可达到100000mg/L,产水TDS在1200-1300mg/L;在预处理+石膏晶种法MVR蒸发结晶工艺中试实验中,验证了石膏晶种法MVR蒸发结晶工艺处理脱硫废水的可行性,在“盐腿淘洗+外排母液”的协调作用下,可以达到外排石膏和氯化钠盐的分离,外排结晶盐(氯化钠)为纯白色晶体,各项指标均满足工业盐优级标准,外排二次冷凝水满足回用标准。根据工艺路线比选,针对不同工程需求,可选取适当处理工艺,实现废水大量回用、少排放或者“零排放”。脱硫废水回用技术在燃煤电厂和煤化工行业具有十分广阔的应用前景。在蒸发结晶工艺中,应深入研发结晶盐提纯技术,可作为工业盐产生经济效益。经济可靠的废水回用工艺既有利于工业废水的处理,又可产生较好的环境效益、经济效益和社会效益。
[Abstract]:At present, most large capacity coal-fired generating units in China are equipped with wet flue gas desulfurization (WFGD) devices, and a large amount of desulfurization wastewater will be produced by wet desulfurization process. Therefore, it is necessary to develop a comprehensive reuse technology for wastewater and evaluate its practical application effect. Based on the analysis of wastewater quality, pretreatment, membrane concentration and evaporation crystallization experiments were carried out on the basis of the present application of desulfurization wastewater reuse technology. The field engineering experiment of desulphurization wastewater was carried out by pretreatment gypsum crystal seed MVR evaporation crystallization process. Through comparison and screening, it is concluded that the dosage of calcium hydroxide and sodium sulfate in desulphurization wastewater of this plant is 13.7g / L ~ (-1) L ~ (-1) 路L ~ (-1) 路L ~ (-1) H is 12.5.After treatment, the water quality accords with the water quality requirement of gypsum crystal seed evaporative crystallization influent water quality and the operation pressure of DTRO-type reverse osmosis is higher. Under the operating pressure of 75bar, the TDS of concentrated water can reach 1000 mg / L, the TDS of producing water is 1200-1300 mg / L, the feasibility of treating desulfurization wastewater by MVR evaporation crystallization process of gypsum crystal seed is verified in the pilot-scale experiment of MVR evaporation crystallization process with pre-treated gypsum crystal seed method. Under the coordinated action of "salt leg washing out mother liquor", the separation of gypsum and sodium chloride can be achieved. The outer discharge crystal salt (sodium chloride) is a pure white crystal, and each index meets the standard of industrial salt quality. The secondary condensed water discharged out meets the reuse standard. According to the comparison and selection of the process route, according to the different engineering requirements, the appropriate treatment process can be selected to realize a large amount of waste water reuse, less discharge or "zero discharge". Desulphurization wastewater reuse technology has a very broad application prospect in coal-fired power plant and coal chemical industry. In the process of evaporation and crystallization, the purification technology of crystalline salt should be developed deeply, which can be used as industrial salt to produce economic benefits. The economical and reliable wastewater reuse process is not only beneficial to the treatment of industrial wastewater, but also can produce better environmental, economic and social benefits.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X773

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