无机调理剂对城市污水处理厂污泥二次深度脱水的研究

发布时间：2018-04-02 07:36

本文选题：污泥　切入点：二次深度脱水　出处：《山东大学》2015年硕士论文

【摘要】：城市污水处理厂污泥二次深度脱水是污泥的减量化、资源化和降低污泥处理处置成本的一项十分关键性的环节,但目前国内外对污泥二次深度脱水方面的研究还较少,特别是对小分子无机化学调理剂作用机理的研究。本文旨在探究两种小分子化学调理剂(FeCl3和AICl3)在调理一次脱水污泥时的作用机理,从而揭示影响污泥二次深度脱水性能的主要因素,为小分子无机化学调理剂在污泥二次深度脱水上的应用奠定理论基础。在实验中,以污泥经过压滤脱水后泥饼含水率作为污泥二次深度脱水性能的评价指标,通过研究污泥调理前后污泥内水分分布、颗粒粒径、颗粒表面电荷、胞外聚合物(EPS)组分和絮体微观结构的变化,分析两种调理剂的作用机理。另外,对硅酸盐、FeCl3、AICl3和粉煤灰复配进行研究,进一步改善污泥二次深度脱水性能,探究各种药剂的投加量、投加比、浓度、复配方式和投加顺序对污泥脱水后含水率的影响,其主要结果如下：(1)当使用AICl3调理一次脱水污泥时,随着AICl3投加量的增加,污泥脱水后的含水率先降低后增高,在AICl3投加量为8g/300g原污泥时,污泥含水率可以达到最低的54.03%,污泥颗粒表面的正电性逐渐增强,污泥颗粒粒径先增大后减小,在AICl3投加量为8g/300g原污泥时达到最大的299.56μm,污泥絮体凝聚得越来越紧密,大量的非自由水转化成自由水,在外界压力的作用下得以脱去,从而最终改善了污泥的二次深度脱水性能。(2)当以FeCl3调理一次脱水污泥时,随着FeCl3投加量的增加,污泥脱水后的含水率先降低后增高,在FeCl3投加量为10g/300g原污泥时,污泥含水率可以达到最低的55.7%,污泥颗粒表面负电荷被逐渐中和,颗粒正电性逐渐增强,污泥颗粒粒径从64.26μm增大到97.18μm,最后降低。污泥EPS组分中的蛋白质、多糖和DNA含量都随FeCl3投加量的增加逐渐增大,说明污泥絮体和内部生物颗粒被破坏,同时污泥内部水分分布发生变化,大量的结合水和自由水转变成间隙水,在外界压力的作用下,污泥絮体进一步凝聚,内部的间隙水转化成自由水从污泥中脱去,从而大大提高了污泥二次深度脱水的性能。(3)在使用硅酸盐、FeCl3和粉煤灰复配调理300g原污泥时,K2SiO3对污泥脱水的效果要好于Na2SiO3,K2SiO3、FeCl3和粉煤灰的最佳投加量分别为8g、10g和10g时,污泥的含水率可被降到最低的39.9%,而用K2SiO3、 AlCl3和粉煤灰复配调理300g原污泥,K2SiO3、AlCl3和粉煤灰的最佳投加量分别为8g、8g和10g时,污泥的含水率可被降到的41.5%,几种药剂配成溶液后的浓度对污泥脱水性能的影响可忽略不计,药剂的最佳投加顺序为硅酸盐、FeCl3、粉煤灰和硅酸盐、AlCl3、粉煤灰。
[Abstract]:Secondary deep dewatering of sludge in municipal wastewater treatment plant is a key link of sludge reduction, reuse and reducing the cost of sludge treatment and disposal, but there are few researches on secondary deep dewatering of sludge at home and abroad. Especially the study on the mechanism of small molecule inorganic chemical conditioning agent. This paper aims to explore the action mechanism of two kinds of small molecule chemical conditioning agents (FeCl 3 and AICL 3) in primary dewatering sludge. Thus, the main factors affecting the secondary deep dewatering of sludge were revealed, which laid a theoretical foundation for the application of small molecule inorganic chemical conditioning agent in sludge secondary deep dewatering. The moisture content of sludge cake was used as the evaluation index of sludge secondary deep dehydration. The water distribution, particle size and surface charge of sludge were studied before and after sludge conditioning. The changes of extracellular polymer (EPS) components and the microstructure of flocs were analyzed, and the mechanism of the two conditioners was analyzed. In addition, the mixture of silicate FeCl _ 3, AICL _ 3 and fly ash was studied to further improve the secondary deep dehydration performance of sludge. The effects of dosage, dosage ratio, concentration, combination mode and order of various chemicals on the moisture content after dewatering of sludge were investigated. The main results are as follows: 1) when AICl3 is used to regulate the dewatered sludge, with the increase of the dosage of AICl3, After sludge dewatering, the moisture content of sludge decreased first and then increased. When the AICl3 dosage was 8g/300g raw sludge, the water content of sludge could reach the lowest 54.03. The positive electrical property of sludge granule surface gradually increased, and the diameter of sludge granule increased first and then decreased. When the amount of AICl3 is 299.56 渭 m, the sludge floc is condensed more and more closely, and a large amount of non-free water is converted into free water, which can be removed under external pressure. Thus, the secondary deep dewatering performance of sludge was improved finally. (2) when the sludge was treated with FeCl3, the moisture content of the sludge decreased first and then increased with the increase of FeCl3 dosage, and when the FeCl3 was added to the original sludge of 10g/300g, the water content of the sludge decreased and then increased with the increase of the dosage of FeCl3. The sludge moisture content can reach the lowest 55.7%, the surface negative charge of sludge particle is neutralized gradually, the positive charge of sludge particle increases gradually, the diameter of sludge particle increases from 64.26 渭 m to 97.18 渭 m, and finally decreases. The protein in the EPS component of sludge is reduced. The contents of polysaccharides and DNA increased with the increase of FeCl3 dosage, indicating that sludge flocs and internal biological particles were destroyed, and the water distribution in sludge changed, and a large amount of bound water and free water changed into interstitial water. Under the action of external pressure, sludge flocs are further condensed, and the inner interstitial water is converted into free water to be removed from the sludge. Therefore, the performance of secondary deep dewatering of sludge is greatly improved.) when the mixture of silicate FeCl3 and fly ash is used to treat 300g raw sludge, the effect of K2SiO3 on sludge dewatering is better than that of Na2SiO3K2SiO3FeCl3 and fly ash is 8g 10g and 10g, respectively. The water content of sludge can be reduced to the lowest 39.9g, and the optimum dosage of K2SiO3, AlCl3 and fly ash is 8g and 10g, respectively, when the mixture of K2SiO3AlCl3 and fly ash is used in the treatment of 300g raw sludge, and the optimum dosages of K2SiO3AlCl3 and fly ash are 8g / g and 10g, respectively. The water content of sludge can be reduced to 41.5. The influence of the concentration of several kinds of agents on sludge dewatering performance can be neglected. The optimum dosing order of the agent is silicate FeCl _ 3, fly ash and silicate AlCl _ 3, fly ash.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703

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