高铁酸盐-Fenton联合氧化法对焦化废水的处理研究

发布时间：2018-04-20 09:42

本文选题：高铁酸盐 + Fenton　；参考：《太原理工大学》2017年硕士论文

【摘要】：随着我国经济、社会、科学技术的迅猛发展,以及人民生活水平的逐步提高,水环境的污染问题也日趋严重。焦化废水是一类难降解的有机废水,多环芳烃是其中一类典型的有机污染物,具有可生化性低、生物毒性高,且致畸、致癌、致突变的性质,因其化学稳定性较高,故在自然界中不易被降解,很可能通过食物链的形式进入生物体内,对人类的发展产生严重的危害。除此之外,焦化废水中还含有大量悬浮的原煤和焦煤颗粒,这种小粒度的悬浮颗粒沉降性能较差,为焦化废水的净化处理带来了一定的麻烦。本文尝试将高铁酸盐氧化法与Fenton氧化法联用,以菲作为研究对象,探索了高铁酸盐-Fenton联合氧化法氧化降解菲的最佳反应条件及其降解效果,随后探究了高铁酸盐-Fenton联合氧化法对水溶液中悬浮煤颗粒的絮凝效果,并考察了此方法对实际焦化废水的处理效果,为实际焦化废水的处理拓展了思路。首先利用单因素实验探索了高铁酸盐氧化法对菲的氧化降解。结果表明,高铁酸钾与菲的反应在100 s后就已基本结束,且pH为中性时,高铁酸钾对菲的氧化效果最好。温度对反应的影响不大,温度的升高有助于高铁酸钾对菲的降解率和反应速率的提升。通过改变反应物浓度发现,高铁酸钾浓度与菲降解率呈现正相关趋势,高铁酸钾浓度的增加能够有效推动反应的进行,而菲初始浓度对反应的影响却很小,随着菲初始浓度的增加,菲的降解率及反应速率有轻微的下降。通过对反应动力学的研究发现,当高铁酸钾或菲初始浓度过量时,高铁酸钾对菲的降解过程符合假一级反应动力学。在单因素实验结果的基础上,设计了高铁酸盐-fenton联合氧化法降解菲的正交试验。结合成本因素,高铁酸盐-fenton联合氧化法降解菲的最佳条件为:初始溶液ph=5、K_2FeO_4反应时间为40s、后续fenton反应时间为15min,试剂投加比例为:phe:K_2FeO_4(n/n)=3:1,phe:H_2O_2(n/n)=1:2。通过对fenton试剂硫酸亚铁投加量的研究发现,过量的硫酸亚铁会导致菲降解率的下降,而从经济方面考虑,硫酸亚铁的投加并不是必要的。测定反应过程中的toc可知,在本实验浓度范围内,对菲的完全降解并未能得以实现。对比高铁酸盐氧化法、fenton氧化法和高铁酸盐-fenton联合氧化法发现,高铁酸盐-fenton联合氧化法有着明显的优势。通过对煤颗粒表面zeta电位的测定,研究高铁酸盐-fenton联合氧化法对煤颗粒絮凝沉降的影响。结果表明,煤颗粒表面带负电,降低溶液ph有利于降低煤颗粒表面zeta电位的绝对值。高铁酸钾在中性溶液中对煤颗粒表面zeta电位的影响较为明显,随着高铁酸钾投加量的增加,煤颗粒表面zeta电位的绝对值先降低后升高。在本实验浓度范围内,无机阳离子的适量加入能够改善煤颗粒的沉降性能。过氧化氢的加入可以与高铁酸钾形成优势互补,说明高铁酸盐-Fenton联合氧化法能够起到促进煤颗粒沉降的效果。最后,考察了高铁酸盐-Fenton联合氧化法对实际焦化废水的处理效果。结果表明,当pH为5、高铁酸钾投加量为6 mmol/L、反应时间为40 s、Fenton试剂过氧化氢与高铁酸钾的摩尔比为6:1、反应时间为15 min时,高铁酸盐-Fenton联合氧化法对实际焦化废水的处理效果最好,此时,COD、氨氮、SS的去除率分别达到了69.27%、75.95%和89.81%。将处理过的水样与原水样相比发现,高铁酸盐-Fenton联合氧化法也会对焦化废水起到较好的脱色作用。
[Abstract]:With the rapid development of economy, society, science and technology and the gradual improvement of people's living standards, the pollution of water environment is becoming more and more serious. The coking wastewater is a kind of refractory organic wastewater. Polycyclic aromatic hydrocarbons are one of the typical organic pollutants, which have low biodegradability, high biological toxicity, teratogenic, carcinogenic and mutagenicity. Because of its high chemical stability, its chemical stability is not easy to be degraded in nature, it is likely to enter the organism through the form of food chain, causing serious harm to human development. In addition, the coking wastewater also contains a large number of suspended raw coal and coking coal particles, and the small particle size of suspended particles has poor settling performance, which is a coking wastewater. This paper attempts to combine the ferrate oxidation method with the Fenton oxidation process and the phenanthrene as the research object, to explore the optimal reaction conditions and degradation effect of the oxidation degradation of phenanthrene by the combined oxidation of ferrate -Fenton, and then explore the combined oxidation of ferrate -Fenton for the suspension of coal in aqueous solution. The effect of the flocculation of the particle on the treatment of the actual coking wastewater was investigated and the thought of the treatment of the actual coking wastewater was expanded. First, the oxidation degradation of phenanthrene by the ferrate oxidation method was explored by single factor experiment. The results showed that the reaction of potassium ferrate to phenanthrene was basically finished after 100 s, and when pH was neutral, high iron was found. The effect of potassium on the oxidation of phenanthrene is the best. Temperature has little effect on the reaction. The increase of temperature can help potassium ferrate to improve the degradation rate and reaction rate of phenanthrene. By changing the concentration of the reactant, it is found that the concentration of potassium ferrate has a positive correlation with the phenanthrene degradation rate, and the increase of the concentration of potassium ferrate can effectively promote the reaction. The effect of the initial concentration of phenanthrene on the reaction was very small. With the increase of the initial concentration of the phenanthrene, the degradation rate and reaction rate of phenanthrene decreased slightly. Through the study of the reaction kinetics, it was found that when the initial concentration of potassium ferrate or phenanthrene was excessive, the degradation process of the phenanthrene accorded with the pseudo first order reaction kinetics. In the single factor experiment results. On the basis of this, the orthogonal experiment of phenanthrene degradation by ferrate -fenton combined oxidation method was designed. Combined with cost factors, the best conditions for the degradation of phenanthrene by the combined oxidation of ferrate -fenton were ph=5, the reaction time of K_2FeO_4 was 40s, the subsequent Fenton reaction time was 15min, and the ratio of the reagent to the reagent was phe:K_2FeO_4 (n/n) =3:1, phe:H_2O_2 (n/n). Through the study of the dosage of Fenton reagent ferrous sulfate, it is found that excessive ferrous sulfate can lead to the decline of phenanthrene degradation rate, and from the economic consideration, the addition of ferrous sulfate is not necessary. The determination of TOC in the reaction process shows that the complete degradation of phenanthrene can not be realized in the concentration range of the experiment. The oxidation method, Fenton oxidation and the combined oxidation of ferrate -fenton have found that the combined oxidation of ferrate -fenton has obvious advantages. By measuring the surface zeta potential of coal particles, the effect of the combined oxidation of ferrate -fenton on the flocculation and settlement of coal particles is studied. The results show that the surface of the coal particles is negatively charged, and the pH of the solution is reduced. The absolute value of the zeta potential on the surface of coal particles is reduced. The effect of Potassium Ferrate on the surface zeta potential of coal particles in neutral solution is more obvious. With the increase of the dosage of potassium ferrate, the absolute value of the zeta potential on the surface of coal particles first decreases and then increases. In the concentration range of this experiment, the amount of inorganic cations can improve the coal particle. The addition of hydrogen peroxide can complementation with potassium ferrate, which indicates that the combined oxidation of ferrate -Fenton can promote the settlement of coal particles. Finally, the treatment effect of the combined oxidation of ferrate -Fenton on the actual coking wastewater is investigated. The results show that when pH is 5, the dosage of potassium ferrate is 6. Mmol/L, the reaction time is 40 s, the molar ratio of Fenton reagent hydrogen peroxide and potassium ferrate is 6:1, the reaction time is 15 min, and the combination of ferrate -Fenton oxidation method is the best for the treatment of the actual coking wastewater. At this time, the removal rate of COD, ammonia nitrogen and SS reached 69.27%, 75.95% and 89.81%. compared with the original water samples. Now, ferrate -Fenton combined oxidation will also play a better role in decolorizing coking wastewater.

【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X784

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