高盐有机废水中盐的去除研究

发布时间：2018-02-20 04:02

本文关键词： 超临界亚临界类水滑石除盐　出处：《中北大学》2016年硕士论文　论文类型：学位论文

【摘要】：随着我国工业规模不断扩大,高浓度含盐废水中的污染物种类也越来越复杂,废水中高浓度的可溶性无机盐和难降解的有毒有机物会造成严重的环境污染,对土壤及地表水和地下水、地表水造成破坏。目前,传统的除盐方法耗时长、运行费用高、限制条件较多的特点,而超临界水氧化技术在处理这类高盐有机废水时具有去除率高、反应速度快、无二次污染等特点,但是废水中含盐量增多或者含有大量氯离子时,会使超临界水氧化技术(SCWO)反应器发生阻塞和腐蚀,最终迫使SCWO装置停机、清洗、装配、压力测试和重新启动,严重影响了SCWO装置运行的可靠性和经济性。因此,对高盐有机废水中盐的去除研究,对生态保护和人类将康有重大意义。本文的主要研究内容为:(1)在亚临界条件下,实验室配置10%和5%的氯化钠、硫酸钠和硝酸钙溶液,采用控制变量法,分别研究温度和压力对其溶解度的影响。(2)采用制备类水滑石的方法,通过控制二价、三价金属阳离子和阴离子的最佳配比以及各种参数的控制以寻求去除氯离子的最优条件,从而确定最佳参数。在最优参数下,对于实际废水的处理尽可能地将处理成本降至最低,使其达到更好的推广和应用。研究表明:(1)在亚临界条件下,通过控制反应釜内的温度和压强,对不同浓度的NaCl、Na2SO4、硝酸钙溶液进行处理,收集出水、釜底残液及放空阀的出水,最后测定盐的浓度。三种盐均在高温低压条件下获得最优参数:在350℃,5MPa下,NaCl的去除率为83%,达到峰值;在350℃,4MPa下,Na2SO4的去除率为92%,达到峰值;在350℃,7MPa下,Ca(NO3)2的去除率为62%,达到峰值。(2)在实验室条件下,利用氢氧化钙和偏铝酸钠与水中氯离子结合形成不溶性的沉淀物Ca2Al(OH)6Cl,以达到去除氯离子的效果。通过改变原料的投加方,进一步提高氯离子的去除效率。结果表明,Ca2+:Al3+:Cl-摩尔比为10:4:1,投加方式1:2,氯离子去除率高达90%。在最优条件下对山西某发电厂高氯废水进行处理,表现出该方法的实用性。将实验中获得的Ca2Al(OH)6Cl物质投入到实际电厂原废水中,结果发现,原废水中的重金属Mn去除率高达99%,其它重金属离子也具有一定去除效果。
[Abstract]:Along with our country industry continues to expand the scale of high salt concentration in the wastewater pollutants becomes more and more complex, toxic organic soluble inorganic salts with high concentration and difficult degradation in wastewater will cause serious environmental pollution, the soil and surface water and groundwater, surface water damage. At present, the traditional salt removal method long time, high operation cost, limited conditions more features, and supercritical water oxidation technology has high removal rate in handling this kind of organic wastewater with high salinity, fast reaction speed, no two pollution, but the salt content in waste water by increasing or containing large amounts of chloride ions, the supercritical water oxidation (SCWO) reactor blocking and corrosion, forcing SCWO device downtime, cleaning, assembly, pressure test and restart, seriously affect the reliability and economy of SCWO device operation. Therefore, the organic wastewater with high salinity salt Study on the removal of the health is of great significance for the ecological protection and human. The main contents are as follows: (1) under subcritical conditions, laboratory configuration 10% and 5% sodium chloride, sodium sulfate and calcium nitrate solution, using the control variable method, respectively study the effect of temperature and pressure on the solubility (2). The preparation method of hydrotalcite, by controlling the price of two, control of trivalent metal cations and anions and the best ratio of various parameters to find the optimal conditions for removal of chloride ion, so as to determine the optimal parameters. The optimal parameters for the actual wastewater treatment, as far as possible the processing costs to a minimum, to achieve the extension and application. The research results show: (1) under subcritical conditions, by controlling the temperature and pressure in the reaction kettle, Na2SO4 of different concentrations of NaCl, calcium nitrate solution processing, collecting water, bottom residue and vent The valve outlet, the final determination of the concentration of salt. Three kinds of salt were obtained the optimal parameters in the conditions of high temperature and low pressure: 5MPa at 350 C, the removal rate of NaCl was 83%, reached the peak; at 350 C for 4MPa, the removal rate of Na2SO4 is 92%, reached the peak; at 350 C for 7MPa. Ca (NO3) 2 removal rate is 62%, reached the peak. (2) under laboratory conditions, using calcium hydroxide and sodium aluminate and chlorine ion binding to form insoluble precipitates of Ca2Al (OH) 6Cl, in order to achieve the removal of chloride ion effect. By changing the dosage of raw materials, to further improve the removal efficiency of chlorine ion. The results show that Ca2+: Al3+: Cl- = 10:4:1, adding 1:2, the removal rate of chloride ion of high chloride wastewater in a power plant in Shanxi under optimal conditions up to 90%., show the practicability of the proposed method. The obtained Ca2Al (OH) 6Cl material into the actual the original power plant waste water. It is found that the removal rate of heavy metal Mn in the original waste water is as high as 99%, and the other heavy metal ions also have a certain removal effect.

【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X703

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