微电荷处理印染废水及其在工程中的应用研究

发布时间：2019-04-17 19:55

【摘要】：印染废水是一种常见而多产的工业废水,具有独特的特点。具有排放水量大、色度高、COD高、成分复杂多变,随季节的变化而变化,是工业废水处理的一大难题。其作为工业废水的排放大户,如果不处理,每天都会向环境中排放大量的高分子有机物质,危害水生生物的生长和大气环境,从而危及人类的发展,给环境带来了极大的压力。随着时代的不断进步,人们在服装质量、款式、纺织品的舒服度等方面要求越来越高,这是促成印染行业飞速发展,同时废水成分复杂化、难处理化趋势的主要原因。印染行业所用的染料、助剂都在不断变化,天然纤维逐渐被化学纤维取代,PVA浆料、人造丝碱解物等难生物降解的高分子有机物大量进入废水中,对废水处理技术的要求越来越高。以实际工程案例和所查阅的文献可知,色度和COD指标的控制一直是印染废水行业的瓶颈,本项目依业主要求,也是实际需要,主要控制COD和色度值。在形势所迫之下应用而生的微电荷技术,逐渐以它投资少、运行成本低、效果明显、占地面积少等优势而迅速推广。本项目所采用的微电荷技术不同于常见的铁炭微电解技术,但又有一定的相似性。都是利用了废铁屑这一环保资源,使废水中产生Fe~(2+),起到一定的絮凝作用和在电解过程中使显色基团断裂的原理,铁炭微电解技术的效果有一定局限性。而本项目的微电荷技术是在通有一定的微电流的作用下,增强铁屑的放电功能,电絮凝的效果更强,并且还能自动正负极调换,以防止电极被污染物覆盖而减缓甚至停止反应。本项目小试期间,以专利技术为技术指导,主要试验了三种不同进水(进前微电荷反应器的水)情况下COD和色度的变化情况:(1)进水为原水的情况;(2)进水为原工艺的调节池出水的情况;(3)进水为原工艺的尾水的情况。其中,根据情况在前微电荷反应器内投加一定量的H_2O_2和CaCl_2,投加双氧水的原理:即试验综合微电荷技术和芬顿技术,而铁离子由微电反应放出,生成量不能控制,因此H_2O_2投加量不能确定最佳值,只能通过试验效果来改变投加量,以求找到最佳值;投加CaCl_2的原理:即增加废水中阳离子浓度,试验是否能使废水中微电流增大,增强电絮凝的效果。试验时,根据现场观察到的效果,第一组和第三组投加药剂,两者的投加量在相同的情况下效果差别较明显,试验了投加量不同的多种情况,以工程实际分析的方法找到各自的最佳点。考虑到第二组情况的水是原污水站预处理过后的水,在试验时没有投加任何药剂。最后综合比较,不管是COD去除还是色度去除,第一种情况和第二种情况效果较好,而进水为调节池出水时,因为水质更稳定,效果比进水为原水更稳定,并且最终出水更接近于标准值。
[Abstract]:Printing and dyeing wastewater is a common and productive industrial wastewater with unique characteristics. It is a difficult problem to treat industrial wastewater because of its large discharge, high chromaticity, high COD, complex and changeable composition, which changes with the seasonal change. If it is not treated, it will release a large amount of macromolecule organic substances to the environment every day, endangering the growth of aquatic organisms and the atmospheric environment, thus endangering the development of human beings and bringing great pressure to the environment. With the continuous progress of the times, people in clothing quality, style, textile comfort and other aspects of higher requirements, which promote the rapid development of printing and dyeing industry, at the same time, the composition of wastewater complex, difficult to treat the trend of the main reason. The dyes and auxiliaries used in the printing and dyeing industry are constantly changing. Natural fibers are gradually replaced by chemical fibers, PVA slurry, rayon alkali hydrolysate and other difficult-to-biodegradable high molecular organic compounds enter the wastewater in large quantities. The demand for wastewater treatment technology is getting higher and higher. The control of chromaticity and COD index has always been the bottleneck of printing and dyeing wastewater industry. According to the owner's request, this project mainly controls the COD and chromaticity value according to the requirement of the owner and the actual need. Under the pressure of the situation, the application of the micro-charge technology has been rapidly popularized with its advantages of less investment, lower operation cost, obvious effect and less land area. The micro-charge technology used in this project is different from the common iron-carbon micro-electrolysis technology, but has some similarity. All of them make use of the environmental protection resource of waste iron scrap to produce Fe~ (2) in the waste water, which plays a certain role in flocculation and breaks the chromogenic group in the process of electrolysis. The effect of iron-carbon micro-electrolysis technology has some limitations. In this project, the micro-charge technology is to enhance the discharge function of iron chips under the action of certain micro-current, the electroflocculation effect is stronger, and also can automatically change the positive and negative poles, so as to prevent the electrode from being covered by contaminants and slow down or even stop the reaction. Under the guidance of patented technology, the changes of COD and chromaticity in three different influent (the water of micro-charge reactor) were tested during the pilot project: (1) the influent was the raw water; (2) the influent is the effluent of the regulating tank of the original process; (3) the influent is the tail of the original process. According to the situation, the principle of adding a certain amount of H_2O_2 and CaCl_2, to the pre-microcharge reactor with hydrogen peroxide is as follows: the experimental synthesis of micro-charge technology and Fenton technology, while the iron ion is released by the micro-electric reaction, the amount of production can not be controlled. Therefore, the H_2O_2 dosage can not determine the optimal value, only through the experimental results to change the dosage, in order to find the best value; The principle of adding CaCl_2 to wastewater is to increase the concentration of cation in wastewater and test whether it can increase the micro-current in wastewater and enhance the effect of electroflocculation. In the experiment, according to the effect observed on the spot, the dosages of the first group and the third group were obviously different under the same conditions, and the different dosages of the two groups were tested in a variety of cases. The method of engineering analysis is used to find their best points. Considering that the second group of water is pre-treated water from the original sewage station, no medicament was added to the test. Finally, whether it is COD removal or chrominance removal, the first and second cases have better effect, but when the influent is the effluent of the regulating tank, the water quality is more stable, and the effect is more stable than the influent being the raw water. And the final effluent is closer to the standard value.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X791

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